抄録
For materials showing a clear yield point, the elastic modulus is found within a proportional limit. However, for an unknown yield point material, the relationship between stress and strain is nonlinear. Therefore, it is difficult to find a true elastic modulus. In this report, we analyzed test results mathematically and found that the elastic modulus of nonlinear material. The test results were provided by a universal tester having an intelligent control system. The elasticity-plasticity transition point of nonlinear materials was found by analysis of the data. Therefore, the elasticity region including a nonlinear portion were obtained. We found a true elastic modulus that the behavior of reducibility strain is essentially related to the elastic modulus.
