应力波作用下直杆塑性分叉动力失稳分析

Analysis of dynamic buckling of bars under plastic compression wave with finite element eigenvalue

运用有限元特征值分析方法对应力波作用下直杆塑性分叉动力失稳问题进行了研究.基于应力波理论和相邻平衡准则导出了直杆塑性动力失稳时的有限元特征方程,方程中考虑了应力波效应及横向惯性效应,把直杆的塑性动力失稳问题归结为特征值问题.通过引入直杆塑性动力失稳时的波前约束条件实现了此类问题的有限元特征值解法.

Dynamic buckling of bars under plastic compression wave was studied by finite element method. The finite element characteristic equations were derived on the basis of the adjacent-equilibrium criterion, in which the compression wave propagation and the transverse inertia effect were taken into consideration. And by the use of the dynamic buckling supplementary restraint conditions at the compression wave front of bars at the instant when the buckling occurs, the critical-load and dynamic buckling modes of bars are calculated from the solutions of the finite element characteristic equations.