a students martin brabec ...characterizationofmechanicalbehaviourof oakwood((((quercus, ,, ,...
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CCCCHARACTERIZATIONHARACTERIZATIONHARACTERIZATIONHARACTERIZATION OFOFOFOF MECHANICALMECHANICALMECHANICALMECHANICAL BEHAVIOURBEHAVIOURBEHAVIOURBEHAVIOUR OFOFOFOFOAKOAKOAKOAK WOODWOODWOODWOOD ((((QQQQUERCUSUERCUSUERCUSUERCUS, , , , LLLL.) U.) U.) U.) UNDERNDERNDERNDER DIFFERENTDIFFERENTDIFFERENTDIFFERENT MOISTUREMOISTUREMOISTUREMOISTURE
CONDITIONSCONDITIONSCONDITIONSCONDITIONS
(R(R(R(REPORTEPORTEPORTEPORT 2222/3 /3 /3 /3 –––– 2020202020202020))))
STUDENTS
This work was supported by the Specific University Research Fund of This work was supported by the Specific University Research Fund of This work was supported by the Specific University Research Fund of This work was supported by the Specific University Research Fund of the FFWT Mendel University in Brno (Grant No. LDF_TP_2019015).the FFWT Mendel University in Brno (Grant No. LDF_TP_2019015).the FFWT Mendel University in Brno (Grant No. LDF_TP_2019015).the FFWT Mendel University in Brno (Grant No. LDF_TP_2019015).
Valentino CRISTINIValentino CRISTINIValentino CRISTINIValentino CRISTINIGinevra MANZOGinevra MANZOGinevra MANZOGinevra MANZO
Petr ZATLOUKALPetr ZATLOUKALPetr ZATLOUKALPetr ZATLOUKALAnna OBERLEAnna OBERLEAnna OBERLEAnna OBERLEDominik HESSDominik HESSDominik HESSDominik HESS
Pavlína SUCHOMELOVÁPavlína SUCHOMELOVÁPavlína SUCHOMELOVÁPavlína SUCHOMELOVÁ
ACADEMIC STAFF
David DĚCKÝDavid DĚCKÝDavid DĚCKÝDavid DĚCKÝJakub DÖMÉNYJakub DÖMÉNYJakub DÖMÉNYJakub DÖMÉNYJaromír MILCHJaromír MILCHJaromír MILCHJaromír MILCHPetr ČERMÁKPetr ČERMÁKPetr ČERMÁKPetr ČERMÁKJan TIPPNERJan TIPPNERJan TIPPNERJan TIPPNERMartin BRABECMartin BRABECMartin BRABECMartin BRABEC
Samuel KRAMÁRSamuel KRAMÁRSamuel KRAMÁRSamuel KRAMÁR Jan ZLÁMALJan ZLÁMALJan ZLÁMALJan ZLÁMAL
ldf.mendelu.cz
A source material for this study originated from21212121 DIFFERENTDIFFERENTDIFFERENTDIFFERENT OAKOAKOAKOAK ((((QQQQUERCUSUERCUSUERCUSUERCUS,,,, LLLL....)))) TREES grown closedto Brno was used.
1. S1. S1. S1. SELECTIONELECTIONELECTIONELECTION OFOFOFOF SOURCESOURCESOURCESOURCE MATERIALMATERIALMATERIALMATERIAL
IIIII. PI. PI. PI. PRODUCINGRODUCINGRODUCINGRODUCING OFOFOFOF LUMBERLUMBERLUMBERLUMBER
IIIIII. CII. CII. CII. CONDITIONINGONDITIONINGONDITIONINGONDITIONING OFOFOFOF HALFHALFHALFHALF----PRODUCTSPRODUCTSPRODUCTSPRODUCTS
IIIIVVVVAAAA. P. P. P. PRODUCINGRODUCINGRODUCINGRODUCING OFOFOFOF SPECIMENSSPECIMENSSPECIMENSSPECIMENS
V. PV. PV. PV. PREPARINGREPARINGREPARINGREPARING OFOFOFOF SPECIMENSPECIMENSPECIMENSPECIMEN''''SSSS CAPTUREDCAPTUREDCAPTUREDCAPTURED SURFACESURFACESURFACESURFACE
VI. PVI. PVI. PVI. PERFORMINGERFORMINGERFORMINGERFORMING OFOFOFOF STANDARDIZEDSTANDARDIZEDSTANDARDIZEDSTANDARDIZED MECHANICALMECHANICALMECHANICALMECHANICAL TESTSTESTSTESTSTESTS
VII. PVII. PVII. PVII. PROCESSINGROCESSINGROCESSINGROCESSING OFOFOFOF MEASUREDMEASUREDMEASUREDMEASURED CHARACTERISTICSCHARACTERISTICSCHARACTERISTICSCHARACTERISTICS
The 21 pith quarter-sawn boards originated from21 different trees were OPENOPENOPENOPEN AIRAIRAIRAIR---- ANDANDANDAND KILNKILNKILNKILN----DRIEDDRIEDDRIEDDRIED toequilibrium moisture content (EMC) equal to 12 %.
The two-step making of specimens was employed. The lamellasmade in the first step were conditioned to a target EMCEMCEMCEMC ((((0000 %%%%,,,, 6666 %%%%,,,,12121212 %%%%,,,, 18181818 %%%% ANDANDANDAND 24242424 %%%%)))) and then cut into specimens.
The specimens for TENSIONTENSIONTENSIONTENSION,,,, COMPRESSIONCOMPRESSIONCOMPRESSIONCOMPRESSIONANDANDANDAND SHEARSHEARSHEARSHEAR TESTSTESTSTESTSTESTS in all of three directions(L,L,L,L, R,R,R,R, TTTT) were made.
On the specimens’ surface to be measured in the full-field mode theSTOCHASTICSTOCHASTICSTOCHASTICSTOCHASTIC ANDANDANDAND HIGHHIGHHIGHHIGH----CONTRASTCONTRASTCONTRASTCONTRAST SPECKLESPECKLESPECKLESPECKLE PATTERNPATTERNPATTERNPATTERN sprayed as basic whitethin paint covered by black variously sized speckles was made.
All mechanical tests are carried out by UNIVERSALUNIVERSALUNIVERSALUNIVERSAL TESTINGTESTINGTESTINGTESTING MACHINEMACHINEMACHINEMACHINE ZZZZWICKWICKWICKWICK ZZZZ050050050050/TH/TH/TH/TH 3333AAAAequipped with 50 kN load cell. The displacements and strains were determined bymeans of THETHETHETHE OPTICALOPTICALOPTICALOPTICAL TECHNIQUETECHNIQUETECHNIQUETECHNIQUE BASEDBASEDBASEDBASED ONONONON DDDDIGITALIGITALIGITALIGITAL IIIIMAGEMAGEMAGEMAGE CCCCORRELATIONORRELATIONORRELATIONORRELATION (DIC)(DIC)(DIC)(DIC).
The statistical processing of the results showedAAAA LOWLOWLOWLOW DEPENDENCYDEPENDENCYDEPENDENCYDEPENDENCY OFOFOFOF some characteristics suchas PPPPOISSONOISSONOISSONOISSON''''SSSS RATIOSRATIOSRATIOSRATIOS ONONONON ALLALLALLALL TESTEDTESTEDTESTEDTESTED TOTOTOTO EMCEMCEMCEMC LEVELSLEVELSLEVELSLEVELS.
From the point of view of different mechanicalbehavior under TENSILETENSILETENSILETENSILE ANDANDANDAND COMPRESSIVECOMPRESSIVECOMPRESSIVECOMPRESSIVE LOADLOADLOADLOAD,the results point to STATISTICALLYSTATISTICALLYSTATISTICALLYSTATISTICALLY SIGNIFICANTSIGNIFICANTSIGNIFICANTSIGNIFICANTDIFFERENCESDIFFERENCESDIFFERENCESDIFFERENCES between most materialcharacteristics FORFORFORFOR ALLALLALLALL TESTEDTESTEDTESTEDTESTED EMCEMCEMCEMC LEVELSLEVELSLEVELSLEVELS.
The specimens were cut as clearlaboratory-sized orthotropic blocksaccording to INTERNATIONALINTERNATIONALINTERNATIONALINTERNATIONAL STANDARDSSTANDARDSSTANDARDSSTANDARDS.
IIIIVVVVBBBB. P. P. P. PRODUCINGRODUCINGRODUCINGRODUCING OFOFOFOF SPECIMENSSPECIMENSSPECIMENSSPECIMENS
1
0.9
0.8
Poi
sson
'sra
tio[-
]
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0μTL, 0 % μTL, 6 %
μTR, 0 % μTR, 6 % μTR, 18 % μTR, 24 %
μTL, 12 % μTL, 18 % μTL, 24 %