縦衝撃を受ける２本の弾・塑性棒の最大衝撃応力の評価について

Abstract

When an elasto-plastic bar collides with an elastic bar longitudinally, the true stress at its impact end can be detected by using the strain gages glued on the elastic bar with the help of an one -dimensional elastic wave propagation theory. When two elasto-plastic bars collide each other as in the case of the present study, however, the stress at the impact end of the bar can not be detected using the same method, since the plastic deformation occures at the impact ends of the two bars.This paper is concerned with the estimation of the maximum plastic impact stress at the impact end occured by the collision of the two elasto-plastic bars. The integrated value of stress with respect to the whole impact time corresponding to the impulse is introduced to estimate the maximum plastic impact stress at the impact end. The numerical and experimental results are arranged using the integrated value of the impact stress. The results show that the integrated value is maintained constant, when the stress wave propagates in the bar, and increases linearly with increasing the maximum impact stress at the impact end whether the wave is an elastic wave or a plastic one. Accordingly, the integrated value is useful to estimate the maximum plastic stress at the impact end when two elasto -plastic bars are put into longitudinal collision.