损伤模型在界面元方法中的应用

Application of damage model to interface stress element method

界面元方法只需考虑界面上的正应力和剪应力,因此通常采用低抗拉的Mohr Coulomb屈服准则。考虑到Mohr Coulomb准则不能模拟材料的破坏过程,故本文在界面材料的本构关系中引入了损伤变量,利用标量形式的等效应变衡量材料的受损程度,因而可以有效地模拟材料损伤后应力逐渐减小的过程。与最大拉应力准则相比,损伤方法更能体现材料屈服后实际承载力的弱化过程。数值算例结果与试验结果吻合,证实了本方法在数值模拟方面的正确性。以拱坝作为工程算例,计算变容重加载时坝体损伤变化趋势,并与地质力学模型试验结果加以对比,研究其损伤演化和破坏过程。

The damage variable is introduced into the constitutive relationship of interface material, and the equivalent strain in scalar mode is used to weigh the damage level of the material. Thus, the stress reduction process of the material after damage can be effectively simulated. By using this method the bearing capacity weakening process of the material after yielding can be calculated. The numerical calculation result is in good agreement with experimental data. Furthermore, the calculation result of an arch dam is compared with the experimental data of geological mechanical model to investigate the evolution and process of failure.