Peridynamic含初始缺陷中心平行双裂纹扩展分析

Analysis of the center parallel double-crack propagation with initial casting defects by peridynamics

为了更好地模拟裂纹扩展行为,一种基于非局部理论——近场动力学被提出,PD采用积分的方法避免了传统方法存在的问题,并采用相邻质点间距离和临界延伸率sc的变化来描述物体受力变化规律,更好地模拟了裂纹扩展及多裂纹融合。本文基于PD模拟了没有缺陷不同间距的中心平行双裂纹扩展路径,然后采用降低质点间键的强度,模拟了含随机分布初始缺陷(气孔,夹杂,未熔合)的中心平行双裂纹扩展路径。得到了初始缺陷对不同纵向间距中心平行双裂纹扩展融合及背离路径的影响规律。

To better simulate the crack propagation,a non-local peridynamics(PD)theory was proposed.The PD method uses the integral method to avoid the problem of traditional methods and uses the distance between adjacent particles and the critical elongation change to describe the force variation law.It simulates the behavior of crack propagation and multi-crack fusion better than the traditional method.In this paper,we first simulate defect-free centrally parallel double-crack propagation paths with different initial distances by PD and then reduce the strength of the bonds between the particles to simulate the centrally parallel double-crack propagation path with random distribution initial defects(porosity,inclusion,and incomplete fusion).Finally,we obtain the influence of initial defects on the fusion and deviation path of the center parallel double crack propagation with different longitudinal spacings.