Modulus of Elasticity

1
Modulus of Elasticity Modulus of Rigidity
from Tensile Test
2
Introduction
??????????????????????????????
?????????????????????
???????????????
??? E ??? G
Objective
????? E ???????????? G ???????? tensile test ???
Al 7075 T6 ?????????????????????????????????????
????????????????
3
Theoretical Background
Modulus of elasticity
Stress
Strian
4
Theoretical Background
Modulus of rigidity
Poissons Ratio
Strain Meter
5
Experiment Setup
DRD E
6
Experiment Setup
DRD G
7
Experiment Setup
Instruments
Vernier calipers
Tensometer
Strain gage on specimen
8
Experiment Setup
Instruments
Wheatstone bridge circuit
Strain meter
9
Experiment Setup
Experimental Conditions
1. ???????????????????? ?????????????????? 2.
??? strain gage ??????????????????????????????????
????????? ?????? strain gage ???????????????????
?????????????????????????? 3.
???????????????????????? elastic 4. ??????????
wheatstone bridge ????????????????
????????????????????????? ??????????????????????
????? ???????????????????????????????????????????
? ?????????????????????????????????
??????????????????? wheatstone bridge
?????????????????????????
10
Experiment Setup
Assumptions
1. Strain gage ??????????????????????????????????
??? 2. ?????????????????????????????????????????
??????? ???????????????????? ???????????
???????????????????????????????????? 3.
?????????????????? isotropic
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Experiment Setup
Experimental Principles
12
Experiment Setup
Procedure
13
Experiment Setup
Strain gages setup E
14
Experiment Setup
Strain gages setup G
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Result
Modulus of elasticity E
Test E (GPa)
1 65.1
2 69.7
3 69.1
4 69.0
5 67.2
E 68.0 1.8 GPa _at_ 95 confidence
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Result
Modulus of rigidity G
Test G (GPa)
1 26.5
2 26.4
3 27.1
4 26.3
5 26.3
G 26.5 0.6 GPa _at_ 95 confidence
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Discussion
???????????????????????? elastic
??????????????????????????????? ?
???? elastic
????????????? ????????????????? - ??????????
??????????????????????????? ?????????????????????
?????????? elastic ????????????????????????
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Discussion
E ??? G ??????????? ??????????????????????????????
??????????? ?
?????????????? ????????? ??????????????? ????????????????
Modulus of elasticity 1.8 GPa 3.6 GPa 3.4 4.0
Modulus of rigidity 0.6 GPa 1.4 GPa 0.4 1.5
??????????????????????????????? E ??? G
????????????????????????? ??????? E ??? G
??????????? ?????????????????????????????????????
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Conclusion
?????????????? modulus of elasticity ??????? 68
2 GPa ??? modulus of rigidity ??????? 27 1 GPa
????????????????????????????????????????????????
??????????? ????????????????????????????????????
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