繰返し応力ひずみ曲線を用いた弾塑性変形挙動解析法の検討

抄録

This paper presents the results of the elastic-plastic deformation analysis using a cyclic stress-strain curve with an intention to apply this method for predicting the low-cycle fatigue life.
Uniaxial plastic cycling tests were performed on 21/4Cr-1Mo steel to investigate the correspondence between the cyclic stress-strain curve and the hysteresis loop, and also to determine what mathematical model should be used for analysis of deformation at stress reversal.
Furthermore, a cyclic in-plane bending test was performed on a flat plate to clarify the validity of the cyclic stress-strain curve-based theoretical analysis.
The results obtained are as follows:
(1) The cyclic stress-strain curve corresponds nearly to the ascending curve of hysteresis loop scaled by a factor of 1/2 for both stress and strain. Therefore, the cyclic stress-strain curve can be determined from the shape of hysteresis loop, for simplicity.
(2) To perform the elastic-plastic deformation analysis using the cyclic stress-strain curve is both practical and effective for predicting the cyclic elastic-plastic deformation of structures at the stage of advanced cycles. And Masing model can serve as a suitable mathematical model for such a deformation analysis.