計装化シャルピー試験による動的弾塑性破壊靱性の測定精度上の問題点

抄録

It had been developed in the previous study that dynamic elastic-plastic fracture toughness parameters J_d and T_mat could be evaluated from Instrumented Charpy impact test. However, to popularize this method, strict neasuring method and judging standard on validity of obtained values must be established. One old and important problem to be clarified is a relationship between an instrumented energy (E_t) obtained from area under a load-deflection curve and a dial reading energy (E_r) calculated from a potential energy of hammer.
The purpose of this study is, therefore, to solve this problem at first and also to clarify the dynamic phenomena accompanying with the measurement of load-deflection curve. It is concluded that the energy condition necessary for test without changing the load-deflection relationship is E₀(applied energy)≥ 3E(total absorbed energy). This is the necessary condition to evaluate meaningful values of J_d and tearing modulus (T_mat). Moreover, it is shown how the vibrational wave superimposes the load-deflection curve analyzing the vibrational mode shape of the hammer.