巴西圆盘劈裂破坏的近场动力学建模与分析

Peridynamic modeling and analysis on split failure of Brazilian disks

基于非局部近场动力学(Peridynamics,PD)理论,对含预置裂纹的混凝土巴西圆盘劈裂破坏问题进行建模分析.将结构离散为包含混凝土材料信息的粒子,引入动态松弛、分级加载和失衡力守恒等粒子系统数值算法,构建可以自然模拟脆性裂纹扩展的PD算法体系.对含不同角度单预置中心裂纹巴西圆盘的裂纹扩展过程进行数值模拟,所得结果与试验结果吻合较好,验证所提出的模型和算法正确.进一步采用该方法模拟双预置裂纹巴西圆盘劈裂破坏过程中的裂纹扩展、交汇、贯通过程,通过将所得模拟结果与试验结果进行比较分析,探究该方法处理多裂纹扩展问题的可行性.

The concrete cracked chevron notched Brazilian disks with split are modeled and analyzed based on the nonlocal Peridynamic（PD） theory. The structure is discretized as material points containing concrete material information, and a series of numerical algorithms of particle system including dynamic relaxation, step-by-step loading and non-equilibrium criterion are introduced into the framework of PD for naturally simulating crack growth. The crack propagation process of Brazilian disks with single pre-existing central crack under different initial angles is numerically simulated, and the result is in good consistence with the test result, which verifies the proposed model and algorithm. The crack propagation, intersection and coalescence process in double-notched Brazilian disks are simulated by the method. The feasibility to study multiple crack growth problems using the proposed method is investigated through the comparison and analysis of the simulation results and the test results.