受内压圆管破坏过程的有限元模拟

THE SIMULATION OF COLLAPSE PROCESS FOR CIRCULAR TUBES UNDER INTERNAL PRESSURE BY FEM

本文用有限元方法模拟受内压圆管的弹塑性、大变形破坏过程。在内压达最大值之后出现的分叉现象.将使管子局部管壁明显变薄,并凸出直至胀裂。为能反映破坏进程中压力下降的情形,使计算不出现全面弹性卸载的非真实结果,采用了内面积增大控制的降阶法。

This paper simulated elastic-plastic collapse process of circular tubes with large deformation under internal pressure by finite element method. After internal pressure achieves its maximum value bifurcation phenomena appear, then the local thicknes of tube wall becomes thiner obviously, and protrusion takes place untill collapse. For the present case, to simulate thedecrease of internal pressure during the collapse process, i. e, to avoid unreasonable results of total elastic unloading, a condensation algorithm to control the increase of internal area was used.