2006 年 72 巻 718 号 p. 864-871
In this paper, elastoplastic crushing behavior of circular tubes under axial compressive loading is studied by using nonlinear finite element analysis software MSC.Marc. In particular, effects of strain hardening on the average crushing load P ave in axial collapse are investigated. It is found that the average load P ave depends on the scale of strain-hardening, and the theoretical result of P ave for rigid perfectly plastic material cannot be used to evaluate the load P ave with strain-hardening material. So in order to take into consideration the strain hardening effect on the average load P ave , we propose an energy equivalent flow stress σ flow defined by the value of average effective plastic strain ε p, eq which arises in one folded wrinkle, and evaluate the average load P ave by using σ flow instead of yield stress σ y . This approximate evaluation agrees well with the experimental result.