含初始裂纹巴西圆盘劈裂问题的非局部近场动力学建模

采用近场动力学方法对巴西圆盘劈裂破坏问题进行建模分析.在非局部键型近场动力学(Peridynamics,PD)理论基础上,通过引入物质点对的转动自由度构建双参数微观弹脆性近场动力学本构模型以突破常规模型的应用范围限制,并考虑岩石混凝土类固体材料的宏观拉压异性和断裂特征.引入动态松弛、粒子系统力边界条件和平衡收敛准则等算法,构建了完备的PD求解体系.实现了含不同倾角中心裂纹巴西圆盘受压劈裂破坏全过程的近场动力学数值模拟,裂纹扩展路径及破坏形式均与试验结果高度吻合.进一步分析了初始中心裂纹倾角及其相对长度对巴西圆盘破坏荷载的影响.

Nonlocal peridynamic modeling for split of notched Brazilian disk

The split of Brazilian disk has attracted serious concern of researchers from the fields of elasticity and rock mechanics and engineering. In this paper a modified two-parameter micro-elastic prototyped brittle peridynamic constitutive model was proposed considering the relative rotation of the interactive bonds of material points based on the recently developed nonlocal peridynamic theory, and the mechanical behavior and fracture characteristics of rock-like materials were also taken into account. By introducing a series of physical algorithms including local damping, force boundary, equilibrium and dynamic relaxation of particle system, the failure process of a pre-notched rock-like Brazilian disk with different central cracks were studied with the proposed peridynamic simulation method. The crack propagation paths and failure mode agree well with experimental observation, which provides a promising alternative for numerical simulation of crack growth and fracture.