the influence of material properties to the stress...
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International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 13
190606-3737-IJMME-IJENS © December 2019 IJENS I J E N S
The Influence of Material Properties to the Stress
Distribution on Piston, Connecting Rod and
Crankshaft of Diesel Engine
Muhammad Vendy Hermawan1, Agus Dwi Anggono2*,
Waluyo Adi Siswanto2, Tri Widodo Besar Riyadi2 1) Department of Mechanical Engineering, Akademi Teknologi Warga Surakarta,
Sukoharjo, Indonesia 2) Master Program of Mechanical Engineering, Universitas Muhammadiyah Surakarta,
Jl. A. Pabelan,Kartasura, Sukoharjo, Indonesia *) Correnponding author, [email protected]
Abstract-- This study aims at evaluating stress on piston,
connecting rod, and the crankshaft of the 4-stroke diesel engine
due to compressive and thermal loads. The study applied the
finite element method, the design was made using CATIA V5,
and analysis was carried out in steady-state using ANSYS R15.
Mechanical and thermal compressive loads were applied based
on the actual combustion chamber condition. The focus of this
study was set up by determining the reference points of
observation. The research variable used different types of
material for each component. The piston used alloy cast iron,
AlSi12 CuNiMg Forged and AlSi18 CuNiMg casting.
Connecting rod used AISI 1045 steel, 42CrMo and alloy cast
iron. Crankshaft uses AlSi18 CuNiMg casting, AISI 1045 steel
and alloy cast iron. The study results showed the maximum
stress depending on the material type which had different
properties. Piston experienced thermal and compressive loads
so that maximum stress influenced by the young modulus and
the thermal expansion coefficient of the material. The
maximum piston stress occurred in alloy cast iron material in
the piston pin area. Connecting rod and crankshaft received a
lot of mechanical compressive load, and the young modulus
value was the most influential thing on the stress that occurred.
The connecting rod experienced the highest stress in the big
end area of the 42CrMo material. Crankshaft experienced the
highest stress in the crank journal fillet area on AISI 1045
material.
Index Term-- Stress, Piston, Connecting rod, Crankshaft,
Simulation, Thermal stress
INTRODUCTION
In this global competition era in the automotive
industry, the attempts to develop product quality through research and development need to be carried out
simultaneously. Research and development includes the
development of an important component of a particular
product. The most important part of a car is the engine,
which generally uses combustion motor as a power-
producing component. Crucial components of the
combustion engine are a piston, connecting rod, and
crankshaft. The mechanical characteristic of combustion
motor components should agree to its function so that it can
accede the loads that arise during the engine operation [1].
The automotive industries must be able to respond to the
challenges and security demands regarding their products.
Finding out the feasibility of a certain product can be done
through finite element analysis on the models through the reverse engineering method [2].
A piston is a combustion motor component that serves
to accept the pressure of the combustion results of the
mixture of fuel and gas in the combustor. Then, the pressure
is continued to the crankshaft by connecting rod. The main
purpose of crankshaft is to transmit mechanical power in the
form of translational motion into rotational motion, which is
then used to rotate the transmission shaft of the vehicle.
Materials that can be used to manufacture the combustion
motor component among others are an aluminum alloy, high
alloy steel, cast iron, and titanium [3]. Material 42CrMo
forged steel is better in terms of basic characteristics than 38MnVS6 [4]. The finite element method can be used to
perform the numerical calculation of a model through finite
element analysis. As an example, stress von misses can be
determined from an LSU-5 axle using the finite element
method without performing a complicated manual
calculation [5]. The size of the FE model mesh influences
the predicted results of the finite element model on a
structure [6].
As computer technology develops, recently there is a
lot of software to be used to perform finite element analysis,
one of which is the ANSYS software. As a result, research can be done through simulation and do not necessarily carry
out an experiment that needs an expensive cost.
ANSYS is one of the software for engineering
commonly used in the aircraft industry, automotive and
other industries. Many research studies have been carried
out using this software. In the case of 3D designing, CATIA
software can be used to support research. So, the
collaboration of both software can ease the researcher to
perform finite element analysis simulations [5].
There are several studies on the analysis of stress due
to loads that occur in the piston, connecting rod, and
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crankshaft. Since combustion motor works at high
workloads and temperatures, the research must cover the
analysis of static and thermal stress [7]. The peak stress
value is used to determine the value of the component's
safety factor and points which experience critical stress.
Research on thermal stress occurred in aluminum alloy piston with variations in the ceramic coating thickness has
ever been done. Piston surface with a minimum thickness of
0.2 mm experiences maximum von mises stresses around
300 MPa, while on the 1.6mm coating thickness, it
experiences von mises stress of 270 MPa [8].
The study of the crack evaluation on diesel engine
crankshaft concludes that the maximum main stress value of
44.8 MPa occurred in the crankshaft journal crank fillet. The
stress value that occurs in the crankpin fillet only reaches
6% of the yield stress of the crankshaft material which is
445 MPa [9]. The elasticity of the crankshaft affects the stress distribution in the crank journal crankshaft bearing, so
that research on the selection of The crankshaft material
must be used to determine the effect of young modulus on
the elasticity of the material [10]. Connecting rod is a
component that supplies power from piston to crankshaft.
By using the finite element method, a maximum stress value
in the connecting rod is 464.27MPa, found in the connecting
rod bolt hole [11].
Crankshaft for vehicles is generally made of cast iron
or forged steel. Considering the high performance of the
machine, the choice often falls on forged steel because it guarantees high mechanical properties [12]. The most
common piston material used is aluminum alloy. The
addition of alumina fibers can improve the anti-ablative
properties of AlSi aluminum alloy piston materials [13].
An evaluation study of the optimization design on the
crankshaft model must be carried out to plan the mechanical
structure of a good diesel engine. This current study was
conducted by analyzing stress that occurs in three types of
crankshaft designs. The focus of the observation was carried
out at 4 focus points in the crank journal fillet and fillet
crankpin areas, where critical stress occurred. Maximum
stress on a diesel engine connecting rod occured at the big end, with a stress value reaching 139.8 MPa. The study was
conducted by simulating the connecting rod components of
a diesel engine. The 3D model was created by using CATIA
software, while the FEA simulation was carried out using
ANSYS software [14]. Other studies have concluded that
there is maximum critical stress in the crank journal and
crankpin fillet areas [15]. The greatest potential for cracking
occurs in the crank journal fillet area [16].
Research in stress and strain analysis on the 3D model
of a thin-walled aluminum cylinder with the finite element
method has been conducted. The study is carried out to determine the effect of the number of elements and speed on
stress in the buckling simulation process. Buckling
simulation is done with the variations in the number of
elements and different speeds to see the results of stress and
strain. For variations in the number of elements, the highest
stress is found in the model 3260 which is equal to
6.0944x108 Pa. As for speed, the highest stress occurred at a
speed of 75, amounting to 3.8456 x 108 Pa [17].
The safety factor is the ratio between the yield stress
and the actual stress. It is important to know the value of the safety factor in planning a structure. Research on the safety
factor of the use of the AISI E4340 crankshaft is carried out
by observing the critical stress that occurs in the diesel
engine crankshaft with a compression ratio of 1: 16.5.
Observations are made at 4 degrees rotation position of the
crankshaft, namely 200o, 400o, 600o, and 800o. As a result,
the most optimal safety factor is achieved at 3.04 [18]. In a
study of stress prediction on the connecting rod, it is found
that 42CrMo material has the highest strength, toughness
and good hardening properties [19].
This current study aimed at determining the amount of
static and thermal stress occurs at each location on a piston, crankshaft and connecting rod using different types of
material. So, the maximum stress analysis can be done and
the safety factor value can be obtained as a reference for the
feasibility of using the material [20]. The 3D design was
created using CATIA V5 software, and stress value data
were obtained through simulation with ANSYS R15
software. It is expected that the data obtained can be used as
a reference in researching potential damage, the selection of
materials for combustion engine components and as
improvements to the quality of materials in the future.
METHODOLOGY
To find out the stress value, this study used a
numerical method. Finite element analysis was used to
determine resulted stress value. The research model used a
4-stroke diesel engine combustion motor component. The
model was made into a 3D design. The design was made
using CATIA V5 software. Stress analysis was carried out
using ANSYS R15.0. software. The analysis was performed
on each component using different material variations. CAE
parameter input covers material property value, thermal
boundary condition, and static load.
Before doing the simulation, software verification was performed. Verification is a checking process if the
operational logic of a computer model/program matches the
logic of a flowchart. Simply, it checks the error in the
program. Verifying means examining whether a simulated
computer program is running as intended, by checking a
computer program [21]. Validation is whether the abstract
simulation model (as opposed to a computer program) is an
accurate representation of the actual model [22].
Verification was done by running the ANSYS
simulation verification program. Three types of verification
simulations were performed, the first with the VMMECH001 code for static structural. The simulation was
done by assembling three prismatic rods in the axial
direction, then clamping at both ends. Furthermore, subject
to axial loads F1 and F2. F1 was applied to the contact
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surface between rods 2 and 3. F2 was applied to the contact
surface between rods 1 and 2. The mesh size was 0.5 inches.
The data being investigated were the maximum stress value
and displacement.
The second verification coded VMMECH005
was applied in steady-state thermal simulation. The simulation model was in the form of two layers of the wall
where The inner wall surface temperature was 3000°F and
the coefficient of surface convection 3.333x10-3
BTU/s.ft2°F. The outside wall had an 80°F ambient
temperature and a 5.556x10-4 BTU/s.ft2°F outer surface
convection coefficient. Thermal stress verification
considered the VMMECH005 verification code by adding a
compressive force of 20000N to the inner surface of the
wall in an axial direction, clamped to the outer wall surface.
The data being investigated were the maximum stress value
3-Dimensional Design The design process was initiated by measuring all
dimensions of the original component. Then, the geometry
data obtained were used to create a design in CATIA V5.
The original component image is shown in figure 1 and the
3D model is shown in figure 2.
a) b)
c)
Fig. 1. Original components a) Piston, b) Connecting rod, c) Crankshaft
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a) b)
c)
Fig. 2. 3-Dimensional model a) Piston, c) Connecting rod, c) Crankshaft
This study was conducted by making reference points as the focus of the observation. The next, stress values at each
reference point were recorded and analyzed. The reference point numbering is shown in figure 3.
a) b)
c) Fig. 3. Reference point numbering as the focus of the observation,
a) piston, b) connecting rod, c) crankshaft
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Boundary Condition
The boundary conditions consist of thermal
boundary conditions that describe the combustion chamber
temperature and static structural conditions by applying the
compressive forces.
Steady-State Thermal Boundary Condition
Thermal boundary conditions completed by
including temperature conditions in combustion chamber.
Heat transfer occurs by means of convection and
conduction. The expected output is the temperature
distribution that occurs in each test component. The thermal
boundary condition parameters are defined in figure 4 (Cerit
& Coban, 2014).
From connecting rod and crankshaft components, it
is assumed that the thermal boundary conditions refer to the inside part of the piston. The ambient temperature is 110oC
and the coefficient of convection heat transfer is 1500
W/m2oC. Thermal boundary condition is illustrated in figure
4
Fig. 4. Thermal boundary condition, a) Piston, b) connecting rod, c) crankshaft
Static-Structural Boundary Condition
The static-structural boundary condition is performed by including the force parameter that occurs in the combustion
chamber and the location of the fix constraint. The expected output from this simulation is the stress data of each component. The compressive force parameter originated from engine specification data on the manual book as presented in table 1.
Tabel I
4-stroke Diesel Engine Specification
Specification
Engine type 4 inline, 16 Valves, DOHC, D-4D
Cylinder volume (cc) 2494
Diameter x Stroke length (mm) 92.0 x 93.8
Maximum Power (Ps/Rpm) 180/2600
Maximum Torque (Nm/Rpm) 183/4000
Fuel system type Common Rail Type
Fuel Diesel
Steering (Power Steering) with (Electric Power Steering)
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From table 1, the maximum force is 180 Ps, which occurred at the rotational speed of 2600 rpm. The required data
are the maximum force that occurred in each cylinder. From the calculation using force and torque basic formula, it is
obtained that the force value is 65141 N or 16200 N for each cylinder.
In the simulation, the application of static boundary conditions is illustrated in figure 5.
Fig. 5. Static structural boundary condition, a) piston, b) connecting rod, c) crankshaft
This current study used variations in the material composition of each component. The difference in the material
type leads to differences in material properties. The piston applied a variety of Aluminum AlSi 18 CuNiMg casting materials,
forged AlSi 12 CuNiMg and cast iron alloys. The connecting rod held a variety of cast iron alloy material, 42CrMo steel, and
AISI 1045 steel. Crankshaft adressed a variety of AISI 1045 steel material, alloy cast iron, and AlSi 18 CuNiMg casting.
The data of the material properties of each material are presented in table 2. Material properties used in this study
taken from Handbook Diesel Engine book [23] and Material Science and Engineering [24].
Table II
Properties of constituent component material
Property Alsi 18
Casting AlSi 12
Forged Cast Iron
Alloy 42 CrMo
Steel AISI 1045
Steel
Density (kg/m³)
2680 2770 7170 7800 7890
Coef. of thermal expansion(x10-
5/ºC)
1.99 1.9 1.098 1.5 1.1
Young modulus(GPa)
68 80 156 210 193
Poisson ratio
0.31 0.33 0.283 0.3 0.269
Tensile yield strength(MPa)
170 280 520 875 515
Thermal conductivity(W/mºC) 143 155 26.6 42 48
RESULTS AND DISCUSSION
From software verification conducted previously, it
was obtained the error value of thermal simulation was
0.20%, thermal stress simulation 0.38 and static structural
0.24. error value was less than 1%, so the software passed
the verification test.
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Stress data were obtained from simulation on a
reference point which became the focus of the observation.
The discussion is presented for each model.
Stress on Piston
Piston stress analysis used three types material
variations, namely alloy cast iron, AlSi 12 CuNiMg forged
Aluminum alloy and AlSi 18 CuNiMg casting. The stress
simulation results are presented in figure 6.
Fig. 6. Results of piston simulation, a) temperature distribution, b) stress distribution
Figure 6.a) shows the piston temperature distribution. Color diffusion occurs in almost all piston bodies. The red
color indicates the area has the highest temperature. It appears that the highest temperature is at the top of the piston and
spreads over the piston surface area. This happens due to the fuel explosion in the area where temperature can reach 700oC. It
can also be seen in the piston body that the temperature gradually decreases. From figure 6.b) in terms of the color contour
distribution, critical stress occurs in the fillet area of the piston surface and the third ring groove. This is because the highest
thermal load is experienced by the upper piston. Thermal loads arise due to high temperatures experienced by the piston.
Critical stress also occurs in the area around the upper piston pinhole. The location is closest to the pedestal area, the piston
pin.
Complete stress value can be seen in the graphic presented in figure 7.
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Fig. 7. Graphic of stress in the piston
From figure 7 the maximum stress value in the alloy cast iron material can be seen, which is 173.73 MPa. It is
because the alloy cast iron has the highest young modulus
value when compared to other piston material variations.
Stress caused by thermal load occurs as a result of rising
piston body temperature. The increase in temperature results
in the expansion of the piston volume where the impact is
the expansion of the piston. The magnitude of expansion is
influenced by the value of the thermal expansion coefficient.
The greater the coefficient value, the greater the volume
expansion. The process of volume expansion is limited by
the cylinder wall at the sides and the piston compressive
force at the top of the piston. This phenomenon causes thermal stress on the piston. This is shown in Figure 6, the
critical distribution of stress occurs in the upper surface area
of the piston and the piston wall around the upper piston
ring area where the maximum temperature is in that area.
The maximum stress value and the stress
distribution trend line for the two types of aluminum
material do not differ much. This is because the young
modulus and the thermal coefficient values of the two
materials do not differ much and are still below the alloy cast iron. Thus, the maximum stress that occurs in
aluminum material does not exceed the stress in the alloy
cast iron. The maximum stress of the forged AlSi 12
CuNiMg is 158.56 MPa, and the AlSi 18 CuNiMg casting is
134.1 MPa. The maximum stress value of the three types of
material occurs in the same area, which is reference point
number 10. This area is the upper part of the piston pin hole,
where this part receives a maximum compressive load and
high temperature.
From the data obtained, the AlSi 18 CuNiMg
casting piston material reduces the most stress because it has
the smallest young modulus value
Stress on Connecting Rod
Figure 8 informs that the maximum stress
distribution occurs in the surface area of the big end
connecting rod hole. The effect of applying compressive
force and thermal conditions causes equal stress in the area.
0
20
40
60
80
100
120
140
160
180
200
1 3 5 7 9 11 13 15 17 19
Cast Iron Alloy
AlSi 12 CuNiMg
forged
AlSi 18 CuNiMg
casting
Reference nodes
Str
ess
(MP
a)
173.73 MPa
134.1 MPa
158.56 MPa
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Fig. 8. Stress distribution on connecting rod Stress distribution also occurs in the small end area and spreads in the trunk area. High compressive load results in
critical stress in the rod area. However, the highest stress occurs in the big end hole where there is connection with the
pedestal. The stress value trendline can be seen in figure 9.
Fig. 9. The graphic of stress value on connecting rod
Figure 9 shown that the maximum pressure value is
occurred in the inner surface area of the big end hole
(reference points 1,2 and 3). The combination of the
compressive load of the piston and the thermal expansion of
the crank journal crankshaft significantly increases stress in
that area. Stress decreases around the rod and rises again in
the fillet area near the small end hole (8th reference point)
and the small end hole area (9th reference point).
0
100
200
300
400
500
600
700
1 2 3 4 5 6 7 8 9 10
Cast iron Alloy
AISI 1045 Steel
42CrMo Steel
Reference nodes
Str
ess
(MP
a)
286.95MPa
356.57MPa
600.33 MPa
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The trend line with the highest stress value is
42CrMo material, with a maximum stress value of 600.33
MPa. When compared to the other types of material,
42CrMo has the highest young modulus value of 210 Gpa.
The AISI 1045 steel material which has a young modulus
value of 193 Gpa with a maximum stress value of 356.57 MPa. Alloy cast iron is the material with the lowest stress
value with a young modulus of 156 Gpa, the smallest of the
other materials with a maximum stress of 286.95 MPa.
Among the three material variations, the highest stress
occurs at the 2nd reference point. The area is the location of
the crank journal shaft. These results inform the 2nd
reference point is the stress center. This occurs as a result of
mechanical compressive loads due to the connecting rod's
compressive forces on the crank journal shaft and volume
expansion of thermal loads. Volume expansion in the area is
blocked by the crank journal shaft, this causes thermal
stress. 42CrMo material has the highest thermal expansion
coefficient value among the three material variations.
Stress on Crankshaft
The focus of the observation on the crankshaft is at
the reference point located in the crank journal fillet and
crankpin fillet areas. The simulation model is shown in
figure 10.
Fig. 10. Stress distribution on the crankshaft
Figure 10 shown that the maximum thermal stress distribution occurs in the fillet area of crank journal. The area is
the closest point to the bearingpoint (metal-bearing) which in the simulation is represented by the fix constraints on the crank
journal surface area. The complete stress value on the crankshaft is presented in figure 11.
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Fig. 11. The graphic of stress value due to temperature load and pressure on the crankshaft
From Figure 11 it can be seen that the stress value caused by
temperature and the compressive load of the piston occurs at
reference points number 1 and 4. The areas are the crank
journal fillet area and are closest to the pedestal location.
The pedestal, in this case, is a metal bearing as a crank
journal support, and the crankshaft pin is paired with the big end hole on the connecting rod. The piston compressive
force distributed by the connecting rod to the crank journal
of the crankshaft. It causes an increase of stress value in the
crank journal area.
The trend line stress value of the three materials is
the same, the highest stress experienced by the AISI 1045
steel material with a maximum stress value of 244.37 MPa
occurring at the 4th reference point. If it is seen from the
material property data in table 3, the AISI 1045 material has
the highest value of young modulus. Then, in the next
sequence is alloy cast iron material. The material with the
smallest young modulus is AlSi 18 CuNiMg casting. Figure
11 informs that the AISI 1045 steel material has the highest
stress value that occurs at the 4th reference point. Alloy cast
iron material ranks second with a maximum stress value of
192.8 MPa occurring at the 1st reference point. The material with the smallest stress value is Aluminum AlSi CuNiMg
18 casting which has maximum stress of 170.84 MPa occurs
at the 1st reference point. The 1st and 4th reference points are
the crank journal crankshaft fillet area.
The material safety factor is very important to be
taken into consideration in the selection of material. This is
to avoid the failure of the engine. Maximum stress on each
component must not exceed the yield stress limits of each
material. A comparison of safety factors is presented in
table 3.
Table III
Comparison of the safety factor of each component
Component Type of Materials Yield strength
(MPa)
Max. stress
(MPa)
Safety factor
Piston
Cast Iron alloy 520 173.73 2.99
AlSi 12 forged 340 158.56 2.14
AlSi 18 casting 210 134.1 1.57
Connecting rod
Cast iron alloy 520 286.95 1.81
AISI 1045 steel 515 356.57 1.44
42 CrMo steel 875 600.33 1.46
Crankshaft
AlSi 18 casting 170 170.84 0.99
Cast iron alloy 520 192.80 2.70
AISI 1045 steel 515 244.37 2.11
The factors influence the value of the safety factor
are the maximum stress and the yield strength of each
material. Safety factor value is the value of the ratio
between yield strength and the maximum stress. In this
120
140
160
180
200
220
240
260
1 2 3 4
AlSi 18 CuNiMg
castingCast iron Alloy
AISI 1045 Steel
Reference nodes
Str
ess
(MP
a)
170.84MPa
192.8MPa
244.37MPa
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study, it is obtained that the young modulus value is the
most influential factor in stress value. The greater the young
modulus, the higher the stress value. In the case of
structures that only experience mechanical loads, the young
modulus is the only value that influences the stress. But in
the case of stress caused by thermal load, the young modulus value and the thermal expansion coefficient affect
the stress value. The relationship between the coefficient
value of thermal expansion to thermal stress occurred is
comparable.
From table 3 it is known that alloy cast iron
material has the highest safety factor on piston, even though
it has the highest stress value. It is because the alloy cast
iron material has the highest yield strength value of 520
MPa. From figure 12, alloy cast iron has the heaviest mass.
This certainly has a poor impact on engine performance.
The safety factor of AlSi 12 forged is quite high but still
below alloy cast iron. AlSi 18 CuNiMg casting material has the lowest safety factor value. Although the AlSi 18 stress
value is quite low, it has the lowest yield strength with a
relatively light mass. From the results of this study, the
material recommended as a piston material is AlSi 12
CuNiMg forged which has a safety factor of 2.14 and a
relatively light mass.
In terms of the connecting rod components, as
provided in table 4, alloy cast iron material has the highest
safety factor at 1.81. So it is most recommended as a
connecting rod material. Table 4 shown that the yield
strength value of alloy cast iron is 520 MPa and the maximum stress that occurs is only 286.95 MPa. In contrast
to 42CrMo steel material which has the highest yield
strength value, but the maximum stress occurred is the
highest at 600.33 MPa. This results in a safety factor of only
1.46, smaller than the alloy cast iron material. The safety
factor value of AISI 1045 material is 1.44. The maximum
stress is greater than alloy cast iron but yield strength is
smaller than alloy cast iron. However, all materials are still within safe limits.
In the crankshaft, cast iron material has the highest
safety factor, followed by AISI 1045. The highest value of
cast iron yield strength when compared to AISI 1045 steel
and AlSi 18 casting. Even though the highest value of the
maximum cast iron stress, the ratio between the value of
yield strength and the stress that occurs is still higher than
the ratio of yield strength to the stress of AISI 1045 steel
material and AlSi 18 casting. The value of the safety factor
of alloy cast iron and AISI 1045 steel is still within safe
limits because it is more than one. AlSi 18 casting material
has a safety factor of less than one, so it is categorized as unsafe material.
The Discussion of the Mass Component Comparison
In material selection, the mass of the model needs
to be taken into account. Material which is too heavy will
slow down the engine performance. The mass of a
component is affected by the density value of the constituent
material. From the simulation data, the comparison of the
mass of each material is shown in figure 12. Steel and alloy
cast iron materials have a high density which can be seen
from their relatively high mass. Aluminum has a relatively low density, this affects the mass of lighter components.
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. Fig. 12. The comparison of mass component
Figure 12 informs that the material with the lightest mass in the piston is the AlSi 18 CuNiMg casting material, 0.362
Kg. The mass of AlSi 12 forged CuNiMg does not differ
much which is equal to 0.374 Kg. Alloy cast iron material
has the heaviest mass. The mass value depends on the
volume and density of the material.
The ratio of connecting rod mass does not have a
significant difference. Of all materials, it only has a
difference of 0.050 Kg. While on the crankshaft, AlSi 18
CuNiMg casting material has the lightest mass of 3,834 Kg,
Alloy cast iron of 10,258 and AISI 1045 of 11,298 Kg.
CONCLUSION
Young modulus value is most influential on the
stress that occurs in components that experience mechanical
compressive loads. The thermal expansion coefficient value
affects the thermal stress that occurs as a result of the
thermal load. The component safety factor is influenced by
the yield strength of its constituent materials.
As a result of thermal and compressive load on the
piston, the young modulus value and the material's thermal
expansion coefficient has the greatest impact on the stresses
in the piston element. The piston analysis results show that
the AlSi 18 CuNiMg casting piston material has the lowest stress with the lowest safety factor value, but still in a safe
category. Forged AlSi 12 CuNiMg material has a relatively
low-stress value and a better safety factor value compared to
AlSi 18. This is because forged AlSi 12 CuNiMg has a low young modulus value, lower expansion coefficient, and
higher yield strength when compared to AlSi CuNiMg
casting. Alloy cast iron material has the best safety factor
value but has the heaviest mass. Thus, AlSi 12 is
recommended as a piston material.
The connecting rod experiences a lot of mechanical
compressive load. The modulus young value influences the
stress the most. The connecting rod analysis shows that the
alloy cast iron material has the lowest stress and the highest
safety factor compared to the other two materials. AISI
1045 steel material has a relatively low-stress value and the lowest safety factor value. 42CrMo steel material has the
highest stress and the lowest safety factor. In terms of mass,
all three materials have almost the same mass. From these
considerations, the alloy cast iron material is the finest when
compared to the other two materials.
The crankshaft continues the compressive force of
the connecting rod, and the mechanical compressive load is
the most dominant cause of the stress. The young modulus
value of the crankshaft material affects the stress that
occurs. Crankshaft analysis shows that the aluminum AlSi
18 CuNiMg casting material has the lowest stress and the
lightest mass, but its safety factor is less than one. Alloy cast iron material has the highest safety factor value. AISI
1045 steel material has the highest stress value but is still
0.362 0.3740.969
0.55 0.605 0.598
3.834
10.258
11.298
0
1
2
3
4
5
6
7
8
9
10
11
12
AlSi
18
casting
AlSi
12
forged
Cast
iron
alloy
Cast
iron
alloy
AISI
1045
steel
42
CrMo
steel
AlSi
18
casting
Cast
iron
alloy
AISI
1045
steel
Piston Connecting rod Crankshaft
Mass
(K
g)
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 26
190606-3737-IJMME-IJENS © December 2019 IJENS I J E N S
within safe limits. So that, the alloy cast iron material is
more recommended.
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