三点弯曲蠕变试验中裂缝扩展的有限元计算分析

SIMULATION OF CRACK EXTENSION IN THREE POINT BENDING CREEP TEST

应用破坏接近度的概念，将压应力作用下的非线性粘弹性模型扩张成了拉应力作用下的岩石力学模型。应用该模型，对三点弯曲蠕变试验中裂缝的扩展过程进行了有限元计算，发现裂缝扩展随时间的变化与应力—应变曲线的形状，尤其是强度破坏点以后的曲线形状密切相关。

Crack extension is related to time dependent behaviour, and is one of the basic problems in the field of rock mechanics. In this paper, by using failure severity concept, a non linear rheological model in compression is developed into new model in tension. This model has been applied to simulate the crack extension in three point bending creep test. By comparison with test results, discussion was carried out. It is found that crack extension with time is closely related to the shape of stress strain curve, especially the descending curve in post failure region.