基于近场动力学理论的准脆性材料的本构力函数的构建

Construction of the constitutive force function of quasi-brittle materials based on the peridynamic theory

近场动力学理论(PD)是基于非局部思想的连续介质力学新理论,用于研究材料破坏问题。根据准脆性材料破坏的线性和非线性的力学行为,在初始微观弹脆性材料(PMB)的本构力函数中引入了键的损伤模型,将键的断裂过程分成了线性的弹性变形阶段和非线性的损伤变形阶段,以此构建了准脆性材料的本构力函数的基本形式。以典型的准脆性材料为例构建了其本构力函数,通过在压缩载荷下对含预制不同角度单裂纹缺陷的类岩材料的裂纹扩展进行PD数值模拟仿真,裂纹起裂位置和扩展方向与试样试验结果在一定程度上保持了一致,证明了该基于近场动力学理论的典型准脆性材料的本构力函数可用于该类材料的破坏分析。

Peridynamic(PD)theory is a new non-local continuum mechanics theory,which can be used for studying material failure.Based on the linear and nonlinear mechanical behavior of failure process of quasi-brittle materials,the basic form constitutive force function of the quasi-brittle material was built by introducing the damage model of bond,which divided the fracture process of the bond into the linear elastic deformation stage and the nonlinear damage deformation stage,into the constitutive force function of the prototype microelastic brittle(PMB)material.Then,a typical quasi-brittle material was used as an example to build this constitutive force function.Experiment and PD numerical simulation of crack growth in rock-like material model with pre-existing single crack at different angles under a compression load were conducted.The results showed that the position of crack initiation and the direction of crack propagation were consistent to some extent,and verified that the constitutive force function of the typical quasi-brittle material was suitable for failure analysis.