research article the effect of rail fastening system ...vossloh clip skl 1 rail pad 1 steel...

Research ArticleThe Effect of Rail Fastening System Modifications onTram Traffic Noise and Vibration

Stjepan LakušiT Ivo Haladin and Maja Ahac

Department for Transportation Engineering Faculty of Civil Engineering University of Zagreb Fra Andrije Kacica Miosica 261000 Zagreb Croatia

Correspondence should be addressed to Ivo Haladin ihaladingradhr

Received 26 December 2015 Accepted 7 March 2016

Academic Editor Rafał Burdzik

Copyright copy 2016 Stjepan Lakusic et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Tram system is a backbone of public transportation in the City of Zagreb In the last decade its fleet has been renewed by 142 newlow-floor trams Shortly after their introduction it was observed that they have a negative impact on the exploitation behavior oftram infrastructure primarily on the durability of rail fastening systems Because of that it was decided to modify existing railfastening systems to the new track exploitation conditions When the (re)construction of tram infrastructure is carried out byapplying new systems and technologies it is necessary to take into account their impact on the future propagation of noise andvibration in the environment This paper gives a short overview of the characteristics of the two newly developed rail fasteningsystems for Zagreb tram tracks their application in construction of experimental track section and performance and comparisonof noise and vibration measurements results Measured data on track vibrations and noise occurring during passage of the tramvehicles is analyzed in terms of track decay rates and equivalent noise levels of passing referent vehicle Vibroacoustic performanceof new fastening systems is evaluated and compared to referent fastening system in order to investigate their ability to absorbvibration energy induced by tram operation and to reduce noise emission

1 Introduction

Tram system is a backbone of public transportation in theCity of Zagreb It consists of more than 116 km of tram tracksused daily by 180 tram vehicles In the last decade systemsmanager Zagreb Electric Tram (ZET) Ltd has renewed itsfleet by purchasing 142 new low-floor trams TMK 2200produced by CROTRAM consortium Another 28 low-floortrams have since then been commissioned from the sameconsortium Shortly after the introduction of new low-floortrams it was observed that this fleet modernization hasincreased exploitation demands on other components of traminfrastructure that is the power supply system and tracksuperstructure

Regarding the effects on the track superstructure themain consequences of the new vehicles introduction havebeen increase in loading forces altered load distributionand altered geometry of wheel and rail contact surface Thisis because new low-floor trams are heavier (on averageup to 60) with differently located center of gravity anddifferent wheel profiles compared to the old ones [1] These

changes in tram track exploitation parameters have causedmore frequent rail fastening system failures which reflectedin the increased rail wear and accelerated track geometrydegradation In event of such mayor rolling stock renewaltrack structure parameters have to be evaluated [2 3] andmodified Because of that ZET Ltd has decided to adjustexisting rail fastening systems to the new track exploitationconditions This was done through technical collaborationwith the University of Zagreb Faculty of Civil Engineeringconsidering the vast experience and expertise in design andsupervision of railway and tram track structures Throughsimilar cooperation there have been several successful designchanges to basic tram track superstructures in order toachieve better vibroacoustic performance and durability thatis in tight curves [4] at busy level crossings [5] and tracksconstructed over underground garage structures [6] Apartfrom acoustic properties major concerns in designing asuitable fastening system are vibrations and impact loads dueto running surface discontinuities which occur at switchesand crossings [7 8]

Hindawi Publishing CorporationShock and VibrationVolume 2016 Article ID 4671302 15 pageshttpdxdoiorg10115520164671302

2 Shock and Vibration

When developing any new rail track system calculationsmodeling and testing of new systems individual componentsmaterial and system as a whole are not sufficient for its directapplication in everyday engineering practice It was thereforedecided to conduct monitoring of new fastening systemsexploitation behavior This was done by construction of thetest track section with built-in new fastening systems [9] Onit the following continuous and periodicmeasurements weremade

(i) Visual inspections of track superstructure

(ii) Measurements of track and weld geometry

(iii) Measurements of stresses and strains of tracks rein-forced concrete foundation slab

(iv) Measurements of the tracks dynamic properties (ievibration damping)

In urban areas due to the proximity between the tram tracksand the residential buildings from the perspective of thesurrounding residents but also the tram users the problemof rail traffic noise and vibrations is particularly pronouncedTherefore if the (re)construction of tram infrastructure iscarried out by applying new systems and technologies it isnecessary to take into account their impact on the futurepropagation of noise and vibration in the environmentThis paper gives a short overview of the characteristics ofthe two newly developed rail fastening systems for Zagrebtram tracks their application in construction of the testtrack section and performance and comparison of noiseand vibration measurements results Data on rail vibrationsoccurring during passage of the tram vehicles will demon-strate the ability of the track experimental constructions toabsorb vibrations and thus prevent their propagation in theenvironment The greater is the ability of the rail fasteningsystems to effectively attenuate rail vibrations induced bypassing tram vehicle the lesser will be the propagation ofnoise and vibration in the environment

2 Development and Characteristics ofNew Rail Fastening Systems

The primary role of the rail fastening system is positioningand fixing of the rails and transferring the vehicle load fromthe rails to the track substructure Generally the type andcharacteristics of fastening system are chosen depending onthe required elasticity of the track planned load and typeof rail On major part of Zagreb tram tracks grooved railsare discreetly laid on the levelling layer made out of microsynthetic concrete and built on reinforced concrete slab Thedistance between levelling layer supports is one meter inthe tram rolling direction Rails are fixed to these blocks byseveral different types of fastening systems [7] mostly by

(i) direct elastic fastening system ZG 32 (Figure 1(a))with 140MNm stiffness developed during the 1980sand still used on about 20 of network

(ii) indirect elastic fastening system with decreased stiff-ness PPE (Figure 1(b)) with 50MNm stiffness devel-oped during the 1990s in order to increase tram tracklife span and used on about 10 of network

(iii) indirect elastic fastening system DEPP (Figure 1(c))with 40MNm stiffness developed in order to solveall the essential flaws of its predecessors and used onabout 50 of network

By reducing the fastening systems stiffness vehicle load istransferred to greater number of bearings (supports) Thisreduces the strain of individual bearing and the speed of loadincrement and prolongs the life of both the bearings and railsReducing the stiffness also lowers the rails frequency whichreflects positively on the overall construction of the track andreduces tram traffic noise and vibration However the above-mentioned indirect elastic fastening systems reflect state ofthe art and the demands on the exploitation behavior of thetracks from the beginning of the 1990s which do not meettodayrsquos highly complex exploitation requirements on Zagrebrsquostram tracks

(i) large tram traffic volume (individual sections ofZagrebrsquos tram tracks that have a traffic volume of upto 15 million gross tons per year)

(ii) high vehicle passing frequency (vehicle frequencywhich is less than 90 seconds between vehicles onindividual sections)

(iii) high wheel loads on low-floor trams (more than 35tons per wheel)

(iv) strict tolerances regarding the narrow 1000mmgauge track geometry

Based on the above requirements during the last few yearsthe faculty has developed five different concepts for newfastening systems Two of them with working titles 21-CTT(Classic Tram Track) (the name was chosen because thestructure of the system is an upgrade of the existing indirectelastic systems) and 21-STT (Slab Tram Track) were chosenfor further development Their characteristics productionrequirements and installation methods best match previousexperiences in the construction and maintenance of tramtracks in Zagreb

21-CTT system (Figure 2(a)) places the rails discreetlyon the levelling layer made out of micro synthetic concretebuilt on reinforced concrete slab (Figure 3) The distancebetween supports is one meter in the tram rolling directionThe rail foot is supported by neoprene pads placed onribbed steel plate laid on the levelling layer To ensure thedurability of individual components and ease the installa-tion during construction and dismantling during the trackreconstruction the underside of the ribbed steel plate is fittedby vulcanization process with elastic pad Vulcanizationprocess enabled production of a compact element electricallyisolated from other components (anchors) but also providedadditional elasticity of the whole fastening system

21-STT system (Figure 2(b)) represents a completelynew solution for tram tracks superstructure constructionin Croatia Its main advantage over the previous systems is

Shock and Vibration 3

ZG 32 Vossloh clip SKL 2Rail pad 1Steel baseplateLevelling layer

(a) ZG 32 fastening system

PPE Vossloh clip SKL 1Rail pad 1Steel baseplateRail pad 2Levelling layer

(b) PPE fastening system

Vossloh clip SKL 1Rail pad 1Steel baseplateRail pad 2Levelling layer

DEPP

(c) DEPP fastening system

Figure 1 Schematic cross sections of rail discrete bearings with ZG-32 PPE and DEPP fastening systems

CTT Vossloh clip SKL 12Rail pad 1Steel ribbed plate RP-180Rail pad 2 (vulcanized)Levelling layer

(a) 21-CTT fastening system

STT Vossloh clip SKL 14Rail pad 1Concrete block

(b) 21-STT fastening system

Figure 2 Schematic cross sections of rail discrete bearings with 21-CTT and 21-STT fastening systems

that the levelling layer (which is quite difficult to construct)is replaced by two block precast concrete sleepers laid onreinforced concrete base slab one meter apart (Figure 4)Upper reinforced concrete slab is constructed after trackhorizontal and vertical alignment adjustmentThis is a directelastic fastening system with one elastic pad between the railfoot and block sleeper

3 Construction of the Test Track Section

In order to determine exploitation characteristics of newlydeveloped tram track fastening systems and get detailedinsight into the behavior of its elements and the trackstructure as a whole in the spring of 2014 a plan and programof test track section construction and monitoring in Savska


Figure 3 Design model of tram track structure with 21-CTTfastening system

Figure 4 Design model of tram track structure with 21-STTfastening system

Street was adopted The said track section was accordingto track maintenance program planned for reconstructiondue to its deterioration For the purpose of the researchthe section was divided into three subsections The firstsubsection is designed as a reference and reconstructed usingthe standard PPE fastening systemThe second reconstructedsubsection is fitted with a 21-CTT fastening system and thethird is reconstructed as 21-STT system (Figure 5)

Figures 6ndash8 show a brief photodocumentation of entiretest track section construction It included the followingphases demolition of existing track (Figure 6(a)) con-struction of the new mechanically compacted base layer(Figure 6(b)) construction of new reinforced concrete slab(Figure 6(c)) construction of the bearings with fasteningsand rail mounting (Figure 7) embedding the tracks withprefabricated concrete plates (Figure 8(a)) and sealing theexpansion joints between the rails and the cover plate(Figure 8(b)) completed tram track and being paved withprefabricated concrete plates in service (Figure 9)

In the phase of construction all three test track subsec-tions were fitted with elements necessary to perform contin-uous and periodic measurements during track exploitationFor the purpose of measurements of stresses and strains oftracks reinforced concrete foundation slab relative deforma-tion (strain) sensors have been built in the concrete slab(Figure 6(c)) For the purpose of visual inspection of bearingsand fastening systems and also for easy access and instal-lation of accelerometers for rail vibration measurementsrevision shafts have been built in prefabricated concreteplates

4 Noise and Vibration Measurements

Themain sources of noise and vibrations on rail tracks are thepropulsion noise of locomotives and power cars coming fromthe engines aerodynamic noise that occurs at very high trainspeeds andwheelrail interactionThe latter is themain noiseand vibrations source in urban rail traffic where the vehiclespeed is not high enough to take into account aerodynamicnoise [12]

When vehicles run on the tracks their weight coupledwith the dynamic forces resulting from running surfaceirregularities causes oscillations that is vibrations of railvehicles and whole track construction At high frequencies(100ndash5000Hz) the energy of these vibrations is propagatedthrough the air in the form of sound waves (noise) Lowerfrequency vibrations (0ndash100Hz) are transmitted from rails tothe lower parts of track structure and surrounding soil [13]

The contribution of noise emitted by rail vibration isa significant component of rolling noise up to 5 kHz [14]One major factor affecting track noise performance has beenidentified to be the attenuation rate of vibration on the railas a function of the distance from the excitation point [15]referred to as track decay rate measured in dBm Namelythe longer the section of the rail that vibrates more noise isemitted to the environment If the rail vibrations attenuaterapidly along the rail and high decay rate is achieved lessnoise is emitted This parameter is often used to describevibroacoustic behavior of a railway track in order to

(i) assess the track side influence on noise level emittedby rail vehicle during pass-by test according to ENISO 3095 [11]

(ii) determine dynamic parameters for separation ofnoise sources [16]

(iii) determine total efective roughness of a vehicle on atest track [17]

(iv) evaluate applied vibration attenuation devices (ierail dampers) [18]

(v) tune and adjust rail dampers [19 20]

On test track in Savska Street noise and vibrations havebeen measured under tram traffic load Measurements havebeen conducted at all three test subsections under referentvehicle that is tram typeTMK2200 (Figure 11) pass-by Pass-by noise and vibration measurements have been conductedunder constant speed of 30 kmh of an empty tram garagenumber TMK 2266 (Figure 13) This measurement setuphas been used in order to establish unified excitation ofnoise and vibrations during the experiments and to measuretrack side contribution to equivalent noise levels Namely byusing unloaded tram with the known characteristics givenin Figure 13 under constant speed throttle condition wheelroughness condition and so forth it was presumed thatdifference in measured equivalent noise levels on differenttest track subsections is solely related to track vibroacousticproperties The measurements were performed during thenight hours in order to eliminate the influence of surround-ing road traffic noise which makes a significant contributionto overall noise levels during daytime


N

WS

E

PPE 21-CTT 21-STT SavskaSavska

Vukovarska

Vukovarska

(a) Test track section layout

PPE 21-CTT 21-STT

55m998400 60m998400 53m998400

Grooved rail Ri-60

Reinforced concrete slab (C 2530 20 cm)Reinforced concrete slab (C 2530 25 cm) Reinforced concrete slab (C 2530 25 cm) constructed after track alignment adjustment

Reinforced concrete slab (C 2025 15 cm)

Subgrade (Ms ge 15 MNm2)

Gravel subbase (Ms ge 50MNm2 min 25 cm)

(b) Test track subsections longitudinal section

Figure 5 Test track section in Savska Street

Accelerometers have been positioned inside each testtrack subsection respecting the minimum distance of 5mfrom rail welds 40m from rail expansion joints according to[17] Based on previous research on these tram track sections[9] it has been established that the substantial length for bothvibration and noise measurements is twice the distance frommicrophone and accelerometer to each side along the trackThis adds up to 10m long track measurement sections (5 toeach side of the microphone and accelerometer position) oneach investigated tram track subsection structure

In lack of regulations related to noise levels of passingtram vehicles as well as vibrations of tram track respon-sible for noise generation European standards suggestedin Comission Regulation (EU) number 13042014 on the

technical specification for interoperability relating to the sub-system ldquorolling stockmdashnoiserdquo [21] have been used Namelyfor type pass-by noise measurements the regulation pre-scribes use of EN ISO 30952013 standard [11] It can beadapted to noise measurements of passing tram vehicleswith certain deviations related to tram speed and distanceof microphone from the track axis The mentioned standardprescribes measurement of two railway track parameters inorder to evaluate the track side contribution to overall noiselevels measured in a typical pass-by test These standards arerelated to rail surface roughness HRN EN 156102009 [22]and to track dynamic properties HRN EN 154612011 [10]Rail surface roughness has not been measured because newlyconstructed experimental track section had the same rails


(a) Demolition of existing tram track

(b) Construction of the new mechanically compacted base layer

(c) Fitting strain gauges to slab reinforcement (left) casting of new reinforced concrete slab (right)

Figure 6 Tram track substructure construction on test track section

installed along all three subsections and they are exposedto same operational conditions hence the rails are assumedto be equally smoothrough in the time on the conductedmeasurements

The parameter that describes the attenuation of the trackvibration amplitude (Figure 10) is referred to as the trackdecay rate (TDR) Track decay rates in vertical and lateraldirection with respect to rail cross section are determinedaccording to [10] by using instrumented hammer as excita-tion force Decay rates can alternatively be measured usingvehicles pass-by and recording time signal of vibrationsin vertical and lateral direction This approach has beenextensively investigated on standard rail track structures anddiscribed in [23ndash27] It has been proposed for inclusionin future version of European standards as an alternative

method of determining track decay rate and is currentlypublished as a CEN Technical Report [17] This approach hasbeen selected for conducting decay rate values of test sectionsdue to several practical reasons that include

(i) shorter measurement procedure (measurements areconducted simultaneously with pass-by noise mea-surements using the same multichannel equipmentfor data acquisition)

(ii) measurements which are performed under realisticloading condition of the track (under dynamic tramvehicle load)

(iii) better coherence of measured data than the measure-ments taken using standardized method [10]


(a) Construction of the levelling layer with PPE fastenings and rail mounting

(b) Construction of the levelling layer with 21-CTT fastenings and rail mounting

(c) Positioning of the sleepers with 21-STT fastenings rail mounting and construction of upper slab

Figure 7 Tram track superstructure construction on track subsections

(iv) less equipment needed for conducting measurements(there is no need for instrumented hammer as vibra-tions are induced by passing vehicle)

(v) avoiding traffic closure and disruption on tramlane (measurements using hammer impact methodrequire around 2 hours on track time which wouldlead to partial traffic closure or a lot of measurementdisruption due to passing rail and road vehicles on thetest site)

(vi) creating safer environment for operators conductingthe measurements (apart from fixing the accelerome-ters to the rail measurements can be made from thesafe distance further away from rail and road vehiclespassing at the test sections)

41 Vibration Measurements Setup Vibration measurementsrelated to dynamic track properties are measured on railfoot and rail head in order to record accelerations in verticaland lateral direction To conduct vibrations measurements


(a) (b)

Figure 8 Embedding the tracks (a) and sealing the expansion joints (b)

Figure 9 Test tram track section after the construction completion

Figure 10 Representation of vertical and lateral vibration decaythrough the rail from the excitation point

at rail cross section certain deviations from the proceduresdescribed in [10 17] had to bemade regarding the positioningand fixing of the accelerometers to the rail Namely measure-ment position in lateral direction had to be moved to thecenter of rail web instead of rail head as described in thestandards due to track being embedded in lane shared withroad vehicles (pavedwithRCplates as described in Section 3)For this reason small revision shafts have been installedduring construction of the track providing the access to therail foot and rail web for accelerometer positioning Rail headouter side had to be sealed in order to create a gap-less surfacefor road vehicles Figure 14 making it impossible to fix thethird prescribed accelerometer

Accelerometers used for conducting measurements arepiezoelectric single directional Bruel and Kjaeligr type 4508Bunits with sensitivity of 100mVG They are fixed to therail by means of magnets and linked to the data acquisitionunit

42 Noise Measurements Setup Noise measurements havebeen conducted in accordance with [11] with the exeption ofpass-by speed that has been limited to 30 kmh (following thenormal operational conditions on tram network in Zagreb)and the distance of microphone to the track axis Thedistance of 25m from track axis has been selected in orderto reduce the influence of the surroundings (reflective andabsorbing surfaces) that coud influence the noise propagationif standardized axis to microphone distance of 75m has beenused Figure 12

For conducting noise measurements microphones Brueland Kjaeligr (type 4189) able to record sound pressure infrequency range from 63Hz to 20 kHz have been usedMicrophone wind guard has been used in order to eliminatethe wind gust effect of a passing tram vehicles Figure 15

43 Data Acquisition For successful determination of equiv-alent noise levels and track decay rates measured quantitieshad to include


TMK 2200

20 20 20

1102 1102

3204

Empty vehicle weightWheel loadConfiguration

Number of passengersMaximum velocityTrack gauge

156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t

Figure 11 Tram type TMK 2200 used as a referent vehicle for pass-by measurements

ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553

ACC 1 and 2 ACC 5 and 6

N

WS

E

Figure 12 Test site layout with marked accelerometer (ACC) and microphone (MIC) positions

Figure 13 Conducting noise and vibration measurements under TMK 2266 pass-by at 30 kmh

(a)

L

V(b) (c)

Figure 14 Accelerometer used for measurements (a) positions of accelerometers on grooved rail cross section green indicates selectedmeasuring positions in vertical and lateral direction and red indicates an accelerometer position proposed in [10] not applicable (b) revisionshaft with accelerometers attached to the rail (c)


(a) (b) (c)

Figure 15 Microphone used for noise measurements (a) data acquisition and microphone positioning on different test sections (b and c)

(i) time record of rail accelerations ndash 119886(119905)[ms2](ii) time record of sound pressure level ndash 119901(119905) [Pa](iii) vehicle pass-by time ndash 119879

119901[s]

(iv) vehicle speed ndash V [ms]

Data acquisition of vibrations and sound pressure has beencarried out using a Bruel and Kjaeligr PULSE Analyzer usingthree input channels two for vibrations and one for soundpressure Data has been acquired using sampling frequencyof 16384 kHz Noise levels have also been measured usinga Bruel and Kjaeligr sound level meter 2270 as a referenceFigure 13

5 Data Processing and Analysis

All gathered vibrations and sound pressure time signals firsthad to be analyzed in time domain in order to identifyvehicle axle positions With known tram geometry and axelpositions (Figure 11) exact vehicle speed and pass-by timecould be derived based on the axel positions identified fromraw acceleration signal in vertical direction (Figure 16) Allvibrations and noise levels observed in frequency domain arethen analyzed and presented in a third octave band of centralfrequencies between 119891

119888= 100Hz and 119891

119888= 5000Hz

51 Vibration Analysis and Track Decay Rate DeterminationFor determining track decay rates out of a time signal ofrail accelerations energy iteration approach has been appliedNamely vibration decay through the rail can be estimatedfor each wheel by fitting a slope to the curve of decayingvibration signal from the point of each wheel passing overthe measuring position [28] The influence of neighboringwheels has to be eliminated in order to achieve comparableresults with standardized method [10] Energy iterationmethod takes into account and eliminates the influence ofneighboring wheels through 2 to 5 steps of iterations

The basic assumption is that the vibration level decaysexponentially from the point 119909 = 0 the point of vibrationexcitation (tram wheel)

119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)

Figure 16 Determining axel positions out of a time signal ofaccelerations of a passing vehicle where119879

119899determines axel position

in a time signal of rail accelerations

119860(119909) presents amplitude of vibrations along the rail 119860(0)presents the amplitude at the wheel-rail contact and 120573 is thevibration decay exponent

According to (1) decay rate can be given as

TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)

TDR can be derived from the ratio 119877(119891119888) This is the ratio of

integrated vibration energy over length 1198712 which includes

the whole vehicle pass-by (1198602sum1198712

(119891119888)) and the integrated

vibration energy on short distance 1198711around the observed

wheel (1198602sum1198711

(119891119888)) 1198711is determined as a shortest distance

between two axels of a vehicle which is in this case equal to18m Observed vibration length around the wheel is minus09mto +09m from the wheel position Figure 17

119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)

asymp 1 minus 119890minus1205731198711 (3)


6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2

Figure 17 Squared vibrations of a tram TMK 2266 passing by (119891119888=

100Hz) 1198821to 1198826are wheel positions TL1 is the integration time

around the wheels and TL2 is integration time over whole trampassing by

where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)

The approximation at the right-hand side in the aboveformula is valid for sufficiently large 119871

2 for example a tram

lengthThequantities1198602

sum1198711

(119891119888) and1198602

sum1198712

(119891119888) can be determined

straightforwardly from measured acceleration signals Thetransducer time signal is passed through third octave bandpass filters resulting in a filtered time signal in range from100Hz to 5000Hz Then for each frequency band theintegrated squared vibration is determined over every wheelover length 119871

1 and for the whole pass-by for 119871

2 Using

Formulae (3) (4) and (5) the vibration energy ratio 119877(119891119888) for

each third octave frequency band is determined [17]Time intervals TL1 that correspond to length 119871

1contain

mostly vibration energy of onewheel but neighboringwheelsalso contribute to energy level especially the wheels on thesame bogie TL1 is hence determined slightly shorter than theshortest distance between the axels on one bogie (18m) inorder to avoid energy overlapping

From (2) and (3) track decay rate can be determined as

TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)

Frequency (Hz)TDR0TDR1TDR2

TDR3TDR4TDR5

Figure 18 Example of determining track decay rate (TDR) invertical direction using energy iteration method for a pass-by of atramTMK2266 on 21-STT section Initially measured level of decayrate is displayed in red and final value of decay rate after 5 steps ofiterations in green

To eliminate the influence of neighboring wheels iterationprocedure is used as follows [17]

(i) A formula for estimating the decay exponent 120573(119891119888) at

each band frequency is based on Formula (3) similarto Formula (5) The vibration energy ratio 119877(119891

119888) is

determined for the whole train pass-by as in Formula(3) and multiplied by 119873119908

119896(119891119888) where 119873 is number

of axles and 119908119896(119891119888) is weighting coefficient

120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)

A starting estimate for the initial decay exponent120573(119891119888) is obtained with119908

1= 2119873This initial condition

assumes that half the vibration energy at each wheeltransmits from other wheels

(ii) The subsequent iterations are then calculated until thedecay exponent 120573(119891

119888) is stable to within 05 dB which

is often achieved after four iteration steps 119896 = 2 to

119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1

119890minus2120573119896minus1|119909119895minus119909119894| (7)

where119909119895minus119909119894is the distance between the currentwheel

119895 and another wheel 119894

The weighting coefficient 119908119896represents a sum of the squared

contributions from all wheels viewed from each wheel andthen summated over all wheels If the decay exponent is largethe effect of adjacent wheels is small and119908

119896quickly converges

to 119908119896=119873 If the decay is small 119908

119896becomes larger Sufficient

convergence is often achieved within around five steps [17]Figure 18

Using this method decay rates on all three test subsec-tions have been determined in vertical and lateral directionDisplayed results are averaged values of track decay rate(TDR) of 3 tram pass-bys


01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)

Frequency (Hz)PPE21-CTT

21-STTLimit V

Figure 19 TDR in vertical direction on three test sections displayedalong with lower limit proposed by [11]

It can be observed from Figure 19 that the vertical trackdecay rates are very similar on all three test sections in lowerfrequency range In frequency range from 1000Hz to 5000Hzbetter performance of vibration attenuation is achieved by21-CTT fastening system 21-STT fastening system has thelowest TDR values that is less vibration attenuation due to itsconstruction with only one elastic under-rail pad and overallstiffer slab track structure Nevertheless all three tested trackconstructions fulfill the standard prescribed lower limits inboth vertical and lateral directions

Lateral track decay rates (Figure 20) are significantlyhigher than the limit values since the rail is embeddedand sealed in a shared running surface of road vehicles asdescribed in Section 3

52 Tram Pass-By Noise As proposed by the Europeanstandards [11] time signals of sound pressure recorded duringtram TMK 2266 pass-by have been expressed as soundpressure level in dB with the reference value 119901

0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)

Time signal of sound pressure levels has to be recorded inminimal length 119879rec which corresponds to 119871

119901119860119890119902125ms levelthat is at least 10 dB lower than sound pressure levels in frontof and after the vehicle (Figure 21)

Measurement time interval 119879119901corresponds to total tram

length which is used for calculation of equivalent soundpressure level of a passing vehicle (119871

119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901

is the 119860-weighted equivalent continuoussound pressure level in dB 119879

119901is the measurement time

interval in s 119901119860(119905) is the 119860-weighted instantaneous sound

01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H

Figure 20 TDR in lateral direction on three test sections displayedalong with lower limit proposed by [11]

950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)

Figure 21 Sound pressure level during tram TMK 2266 passing byon 21-CTT section at 30 kmh 119879

119901represents a measurement time

interval of a whole vehicle pass-by and 119879rec minimal recorded timeinterval

Table 1 Equivalent noise levels of tram TMK 2266 at 30 kmh forall test sections with standard deviation of measured results

Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08

pressure at running time 119905 in Pa and1199010is the reference sound

pressure (1199010= 20120583Pa)

Recorded sound pressure levels of 2 pass-bys at each testsubsection have been recorded for tramTMK 2266 pass-by at30 kmh and the average value is expressed as final equivalentnoise level Table 1

It can be observed that the same referent vehicle atconstant speed of 30 kmh emits different noise levels atdifferent track sections Lowest noise levels are recorded at 21-CTT test section that also corresponds to highest track decayrate measurements At reference test section PPE highestnoise levels are recorded (up to 36 dB higher than 21-CTTand 16 dB higher than on 21-STT subsection)


1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)

Frequency (Hz) Laeq PPELaeq 21-CTTLaeq 21-STT

TDR-V PPETDR-V 21-CTTTDR-V 21-STT

Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)

Figure 22 Spectral representation of equivalent noise levels on testsubsections with respect to track decay rates in vertical direction

In order to assess the influence of track-side contributionto the equivalent noise levels of a passing vehicle at alltest subsections spectral analysis of noise levels has beenconducted in the same frequency range as track decay rates100Hz to 5000Hz in 13 octave bands Figure 22 Verticaldecay rate has been selected for further analysis since it wasconcluded that the horizontal decay rate is much higher dueto rail being embedded in the road surface and had muchlower effect on the noise emissions It can be clearly observedthat the tram pass-by at 30 kmh emits highest noise levels inthe 500Hz to 1000Hz frequency range It has been observedthat there is a correlation between lower noise levels andhigher track decay rates on all three subsections especially in1000Hz to 3150Hz frequency range In this particular rangehighest track decay rate values clearly contribute to lowestnoise levels on 21-CTT subsection This indicates higherdecay rate of the track which still contributes to lower noiseof vehicle pass-bys although the requirement by EN ISO 3095[11] has been met on all subsections Figure 22 Since rollingnoise is not the only contributing factor to overall noiselevels engine noise and other noise sources can also affectequivalent noise level difference between subsections

6 Conclusion

Due to high traffic loads tram tracks in the City of Zagrebare exposed to high stresses they rapidly degrade and deteri-orate To answer the harsh tram traffic operation conditionsand to optimize maintenance procedures two new solutionsfor rail fastening systems were developed named 21-CTT21-STT systems The main objective in developing the newsystemswas to develop a tram track structure whichwould bequick and simple to construct have longer exploitation life beeasy to maintain and have good exploitation characteristicsExploitation characteristics of the developed systems wereinvestigated on the test tram track and compared with areference track built with commonly used PPE fastening

Table 2 Comparison of the characteristics of the surveyed tramwaytrack constructions

Characteristic System21-CTT 21-STT

Constructioninstallation speed = +Constructioninstallation cost + ++Stray current protection ++ +Maintenance = +Exploitation life + ++Vibration attenuation + minus

Noise attenuation ++ += similar to reference PPE track + better than reference PPE track++ significantly better than reference PPE track and minus worse than PPEreference track

system Table 2 gives a summary of the characteristics of thesurveyed track structures

The experience gained during the construction of testsubsection and measurement results led to the followingconclusions

(i) 21-CTT represents an upgrade of existing rail fas-tening solutions For its creation standard rail trackmaterial and elements were used Due to their serialproduction this system can be constructed for muchlower market price By vulcanization of certain partsof the fastening system tram track is isolated andbecomes resistant to the occurrence of stray currents

(ii) 21-STT is a new concept for construction of the tramtrack structures in Croatia It is characterized by veryhigh resistance and low deformation under trafficload and good stress distribution through the trackstructure It is created by using standard elementsof conventional rail tracks its installation is fast andsimple and its maintenance is easy

(iii) Bymeasuring the vibration of track test constructionsand comparing them to reference values recordedon reference PPE subsection it was found that thereis an increase in the overall level of vibration onsubsection 21-STT (caused by the greater stiffnessof track structure) and small reduction of vibrationlevels at the test subsection 21-CTT

(iv) The effect of vibrations on the track noise attenuationhas been observed by determining track decay rateAll three test track subsections arewithin the standardprescribed value It was observed that both new sys-tems have better vibration damping ability at higherfrequencies and that they behave very well in terms oflow noise emission

(v) Results of measuring track decay rate have beenconfirmed by measurements of tram pass-by noiseAt reference test track subsection PPE highest noiselevels are recorded (up to 36 dB higher than 21-CTTand 16 dB higher than on 21-STT subsection)

(vi) 21-CTT makes a commercially cost-effective alterna-tive to existing rail fastening solutions while meeting


all the requirements of amodern tram track structureSuch a system is the optimal solution for the tramtrack superstructure reconstructions

(vii) 21-STT is the optimal choice for the constructionof new and reconstruction of existing tram trackswhen the (re)construction project anticipates theconstruction of new track substructure

Competing Interests

The authors declare that they have no competing interests

Acknowledgments

This work was supported by the Ministry of Science Edu-cation and Sports of the Republic of Croatia within theframework of the Scientific Project ldquoNoise and Vibrationson Tram and Railway Tracksrdquo (Grant no 082-0000000-2185)The authors would also like to express sincere gratitude to theZG Holding doo ZET Edilon)(Sedra HmbH Beton Luckodoo DIV Group doo Gumiimpex-GRP dd Georaddoo and PGP doo for the financial and technologicalsupport given to this study

References

[1] M Ahac Mechanistic-empirical model for tram track gaugedeterioration during exploitation [PhD thesis] University ofZagreb Faculty of Civil Engineering 2013

[2] M Tomicic-Torlakovic G Cirovic S Mitrovic and VBrankovic ldquoOptimisation and ranking of permanent way typesfor light rail systemsrdquo Gradjevinar vol 66 no 10 pp 917ndash9272014

[3] S Jovanovic HGuler and B Coko ldquoTrack degradation analysisin the scope of railway infrastructuremaintenancemanagementsystemsrdquo Gradjevinar vol 67 no 3 pp 247ndash258 2015

[4] S Lakusic V Tkalcevic Lakusic and M Bogut ldquoProtection ofhistorical buildings from rail traffic vibrationsrdquo in Protection ofHistorical Buildings pp 1399ndash1406 CRC PressBalkema Tayloramp Francis Group Rome Italy 2009

[5] I Haladin S Lakusic and M Bogut ldquoAnalysis of tram trafficvibrations in respect to tram track structure and exploitationperiodrdquo in Proceedings of the 20th International Congress onSound and Vibration (ICSV rsquo13) pp 3242ndash3249 InternationalInstitute of Acoustics and Vibration Bangkok Thailand July2013

[6] S Lakusic I Haladin and M Bogut ldquoAnalysis of tram inducedvibration influence on underground garage structure throughexploitationrdquo in Proceedings of the 21st International Congresson Sound and Vibration pp 13ndash17 International Institute ofAcoustics and Vibration Beijing China July 2014

[7] S Lakusic Dynamic behaviour of the tram-track interaction[Doctoral thesis] University of Zagreb Faculty ofCivil Engineer-ing Zagreb Croatia 2003

[8] E Curic D Drenic and Z Grdic ldquoAnalysis of carrying capacityof concrete sleepers for switches and crossings under static anddynamic loadrdquo Gradjevinar vol 66 no 12 pp 1117ndash1124 2014

[9] S Lakusic I Haladin and J Koscak ldquoMonitoring report ontram track fastening system Zagreb 21-CTT and Zagreb 21-STT

on Savska Street in Zagrebrdquo Tech Rep Zagreb MunicipalityTransit System (ZET) University of Zagreb Faculty of CivilEngineering Zagreb Croatia 2015

[10] HRN ldquoRailway applicationsmdashnoise emissionmdashcharacterisa-tion of the dynamic properties of track sections for pass bynoise measurementsrdquo HRN EN 154612011 2011 (HRN EN154612008+A12010)

[11] HRN EN ISO ldquoAcousticsmdashrailway applicationsmdashmeasurementof noise emitted by railbound vehiclesrdquo ISO 3095 2013

[12] B Hemsworth ldquoSTAIRRSmdashstrategies and tools to assess andimplement noise reducing measures for railway systemsrdquo FinalTechnical Report 2003

[13] C EsveldModern Railway Track TU Delft Delft Netherlands2nd edition 2001

[14] D J Thompson and C J C Jones ldquoA review of the modellingof wheelrail noise generationrdquo Journal of Sound and Vibrationvol 231 no 3 pp 519ndash536 2000

[15] C J C Jones D JThompson and R J Diehl ldquoThe use of decayrates to analyse the performance of railway track in rolling noisegenerationrdquo Journal of Sound and Vibration vol 293 no 3ndash5pp 485ndash495 2006

[16] M H A Janssens M G Dittrich F G de Beer and C J CJones ldquoRailway noise measurement method for pass-by noisetotal effective roughness transfer functions and track spatialdecayrdquo Journal of Sound and Vibration vol 293 no 3ndash5 pp1007ndash1028 2006

[17] FprCENTR 16891 ldquoRailway applicationsmdashacousticsmdashmeasurement method for combined roughness track decayrates and transfer functionsrdquo Tech Rep CENTC 256 Institutefor Standardization of Serbia 2016

[18] B Betgen P Bouvet G Squicciarini and D J Thompson ldquoTheSTARDAMP Software an assessment tool for wheel and raildamper efficiency a few words on rolling noise the principles ofrail and wheel dampersrdquo in Proceedings of the AIA-DAGA 2013Conference on Acoustics p 4 Merano Italy 2013

[19] J Maes and H Sol ldquoA double tuned rail dampermdashincreaseddamping at the two first pinnedndashpinned frequenciesrdquo Journalof Sound and Vibration vol 267 no 3 pp 721ndash737 2003

[20] D J Thompson C J C Jones T P Waters and D FarringtonldquoA tuned damping device for reducing noise from railway trackrdquoApplied Acoustics vol 68 no 1 pp 43ndash57 2007

[21] Commission Regulation (EU) No 13042014 of 26 November2014 on the technical specification for interoperability relat-ing to the subsystem lsquorolling stockmdashnoisersquo Official Journalof the European Union p 17 2014 httpeur-lexeuropaeulegal-contentENTXTuri=CELEX32014R1304

[22] ldquoRailway applicationsmdashnoise emissionmdashrail roughness mea-surement related to rolling noise generationrdquo HRN EN156102009 2009

[23] MGDittrich F Letourneaux andHDupuis ldquoBackground foran new standard on pass-by measurement of combined rough-ness track decay rate and vibroacoustic transfer functionsrdquo inNoise and Vibration Mitigation for Rail Transportation Systemsvol 126 pp 197ndash204 Springer Berlin Germany 2013

[24] W Li J Jiang R Dwight and C Schulten ldquoAn investigation of amethod for track decay rate measurement using train pass-bysrdquoin Proceedings of the Australian Acoustical Society Conference2011 Breaking New Ground Acoustics 2011 no 75 pp 563ndash568Gold Coast Austraila November 2011

[25] M G Dittrich ldquoProcedure and applications of combinedwheelrail roughness measurementrdquo in Proceedings of the


NAGDAGA International Conference on Acoustics pp 2ndash4Rotterdam Netherlands March 2009

[26] M G Dittrich ldquoTrack decay rate measurement using thePBA techniquerdquo in Proceedings of the Euronoise 2006 Tam-pereFinland 2006

[27] M T Kalivoda ldquoTrack decay rate of different railway noise testsitesrdquo in Forum Acusticum p 3 Budapest Hungary 2005

[28] M Wirnsberger M G Dittrich J Lub et al ldquoMethodologiesand actions for rail noise and vibration controlrdquo METARAILProject Final Report for Publication 1999

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



When developing any new rail track system calculationsmodeling and testing of new systems individual componentsmaterial and system as a whole are not sufficient for its directapplication in everyday engineering practice It was thereforedecided to conduct monitoring of new fastening systemsexploitation behavior This was done by construction of thetest track section with built-in new fastening systems [9] Onit the following continuous and periodicmeasurements weremade

(i) Visual inspections of track superstructure

(ii) Measurements of track and weld geometry

(iii) Measurements of stresses and strains of tracks rein-forced concrete foundation slab

(iv) Measurements of the tracks dynamic properties (ievibration damping)

In urban areas due to the proximity between the tram tracksand the residential buildings from the perspective of thesurrounding residents but also the tram users the problemof rail traffic noise and vibrations is particularly pronouncedTherefore if the (re)construction of tram infrastructure iscarried out by applying new systems and technologies it isnecessary to take into account their impact on the futurepropagation of noise and vibration in the environmentThis paper gives a short overview of the characteristics ofthe two newly developed rail fastening systems for Zagrebtram tracks their application in construction of the testtrack section and performance and comparison of noiseand vibration measurements results Data on rail vibrationsoccurring during passage of the tram vehicles will demon-strate the ability of the track experimental constructions toabsorb vibrations and thus prevent their propagation in theenvironment The greater is the ability of the rail fasteningsystems to effectively attenuate rail vibrations induced bypassing tram vehicle the lesser will be the propagation ofnoise and vibration in the environment

2 Development and Characteristics ofNew Rail Fastening Systems

The primary role of the rail fastening system is positioningand fixing of the rails and transferring the vehicle load fromthe rails to the track substructure Generally the type andcharacteristics of fastening system are chosen depending onthe required elasticity of the track planned load and typeof rail On major part of Zagreb tram tracks grooved railsare discreetly laid on the levelling layer made out of microsynthetic concrete and built on reinforced concrete slab Thedistance between levelling layer supports is one meter inthe tram rolling direction Rails are fixed to these blocks byseveral different types of fastening systems [7] mostly by

(i) direct elastic fastening system ZG 32 (Figure 1(a))with 140MNm stiffness developed during the 1980sand still used on about 20 of network

(ii) indirect elastic fastening system with decreased stiff-ness PPE (Figure 1(b)) with 50MNm stiffness devel-oped during the 1990s in order to increase tram tracklife span and used on about 10 of network

(iii) indirect elastic fastening system DEPP (Figure 1(c))with 40MNm stiffness developed in order to solveall the essential flaws of its predecessors and used onabout 50 of network

By reducing the fastening systems stiffness vehicle load istransferred to greater number of bearings (supports) Thisreduces the strain of individual bearing and the speed of loadincrement and prolongs the life of both the bearings and railsReducing the stiffness also lowers the rails frequency whichreflects positively on the overall construction of the track andreduces tram traffic noise and vibration However the above-mentioned indirect elastic fastening systems reflect state ofthe art and the demands on the exploitation behavior of thetracks from the beginning of the 1990s which do not meettodayrsquos highly complex exploitation requirements on Zagrebrsquostram tracks

(i) large tram traffic volume (individual sections ofZagrebrsquos tram tracks that have a traffic volume of upto 15 million gross tons per year)

(ii) high vehicle passing frequency (vehicle frequencywhich is less than 90 seconds between vehicles onindividual sections)

(iii) high wheel loads on low-floor trams (more than 35tons per wheel)

(iv) strict tolerances regarding the narrow 1000mmgauge track geometry

Based on the above requirements during the last few yearsthe faculty has developed five different concepts for newfastening systems Two of them with working titles 21-CTT(Classic Tram Track) (the name was chosen because thestructure of the system is an upgrade of the existing indirectelastic systems) and 21-STT (Slab Tram Track) were chosenfor further development Their characteristics productionrequirements and installation methods best match previousexperiences in the construction and maintenance of tramtracks in Zagreb

21-CTT system (Figure 2(a)) places the rails discreetlyon the levelling layer made out of micro synthetic concretebuilt on reinforced concrete slab (Figure 3) The distancebetween supports is one meter in the tram rolling directionThe rail foot is supported by neoprene pads placed onribbed steel plate laid on the levelling layer To ensure thedurability of individual components and ease the installa-tion during construction and dismantling during the trackreconstruction the underside of the ribbed steel plate is fittedby vulcanization process with elastic pad Vulcanizationprocess enabled production of a compact element electricallyisolated from other components (anchors) but also providedadditional elasticity of the whole fastening system

21-STT system (Figure 2(b)) represents a completelynew solution for tram tracks superstructure constructionin Croatia Its main advantage over the previous systems is







DEPP




























N

WS

E


Vukovarska

Vukovarska


PPE 21-CTT 21-STT

55m998400 60m998400 53m998400

Grooved rail Ri-60































(a) (b)










TMK 2200

20 20 20

1102 1102

3204



156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t


ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553


N

WS

E



(a)

L

V(b) (c)



(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation















DEPP




























N

WS

E


Vukovarska

Vukovarska


PPE 21-CTT 21-STT

55m998400 60m998400 53m998400

Grooved rail Ri-60































(a) (b)










TMK 2200

20 20 20

1102 1102

3204



156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t


ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553


N

WS

E



(a)

L

V(b) (c)



(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation


























N

WS

E


Vukovarska

Vukovarska


PPE 21-CTT 21-STT

55m998400 60m998400 53m998400

Grooved rail Ri-60































(a) (b)










TMK 2200

20 20 20

1102 1102

3204



156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t


ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553


N

WS

E



(a)

L

V(b) (c)



(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation






























(a) (b)










TMK 2200

20 20 20

1102 1102

3204



156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t


ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553


N

WS

E



(a)

L

V(b) (c)



(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










TMK 2200

20 20 20

1102 1102

3204



156 + 4670kmh1000 mBo998400Bo998400Bo998400

400 t333 t


ACC 3 and 4

605551654235 1265 835 3465

21-STT21-CTT

2525

25

MIC 3MIC 2PPE MIC 1

183553


N

WS

E



(a)

L

V(b) (c)



(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










(a) (b) (c)



119901[s]





119888= 100Hz and 119891

119888= 5000Hz



119860 (119909) asymp 119860 (0) 119890minus120573|119909| (1)

5 75 10 125 15Time (s)

minus100

minus75

minus50

minus25

0

25

50

75

100T1T2 T3T4 T5T6

Rail

acce

lera

tionmdash

vert

ical

(ms

2)






TDR = 20 log10(119890120573) asymp 8686120573 [dBm] (2)






wheel (1198602sum1198711



119877 (119891119888) =

1198602

sum1198711

(119891119888)

1198602

sum1198712

(119891119888)



6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










6 7 8 9 10 11 12 13 14ALL-time (s)

0

25

5

75

10

125

15W1 W2 W3 W4 W5 W6

ALL

-ACC

-H-S

q1

((m

2)

(s4))

TL1TL1

TL1TL1

TL1TL1

TL2




where

1198602

sum1198711

=

119873

sum

119899=1

1198602

1198991198711

=

119873

sum

119899=1

int

11987112

minus11987112

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198711

120573

119873

sum

119899=1

1198602

119899(119909119899)

1198602

sum1198712

=

119873

sum

119899=1

int

1198712

(119860119899(119909119899) 119890minus120573|119909minus119909

119899|)

2

119889119909

=

1 minus 1198901205731198712

120573

119873

sum

119899=1

1198602

119899(119909119899) asymp

1

120573

119873

sum

119899=1

1198602

119899(119909119899)

(4)




sum1198711

(119891119888) and1198602

sum1198712




2 Using



1contain



TDR (119891119888) = minus

8686

1198711

ln (1 minus 119877 (119891119888)) (5)

10

100

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


TDR3TDR4TDR5





119888) is


119896(119891119888) where 119873 is number


120573119896(119891119888) = minus

ln (1 minus 119877 (119891119888)119873119908

119896(119891119888))

1198711

(6)







119908119896(119891119888) =

119873

sum

119895=1

119873

sum

119894=1












01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit V





0= 20120583Pa

119871119901= 10 log(

119901

1199010

)

2

[dB] (8)





119901119860119890119902119879119901

) according to

119871119901119860119890119902119879

119901

= 10 log( 1119879119901

int

119879119901

0

1199012

119860(119905)

1199012

0

) [dB] (9)

where 119871119901119860119890119902119879

119901




01

10

100

1000

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)


21-STTLimit H


950

900

850

800

750

700

650

60070 80 90 100 110 120 130 140 150

Time (s)

minus10

dB

minus10

dB

Tp

Trec

TMK 2200

LA

(dB(

A) r

ef2

0120583

Pa)





Test section 119871119901119860119890119902119879119901

[dB] SDPPE 845 0321-CTT 809 1421-STT 829 08


pressure (1199010= 20120583Pa)




1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










1

10

100

40455055606570758085

100

125

150

200

250

315

400

500

630

800

1000

1250

1500

2000

2500

3150

4000

5000

Trac

k de

cay

rate

(dB

m)



Equi

vale

nt n

oise

leve

l (dB

(A) r

ef2

0120583

Pa)



6 Conclusion

















Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation












Competing Interests


Acknowledgments


References


































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation
















RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









research article the effect of rail fastening system ...vossloh clip skl 1 rail pad 1 steel...

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