In peridynamic models for fracture, the dissipated fracture energy is regularized over a non-local region denoted as the peridynamic horizon. This paper investigates the influence of this parameter on the dynamic fracture process in brittle solids, using two as well as three dimensional simulations of dynamic fracture propagation in a notched plate for two loading cases. The predicted crack speed for the various scenarios of the initially stored energy, also known as the velocity toughening behavior as well as characteristics of the crack surface topology obtained in different crack propagation regimes in 3D computational simulations are compared with the experimentally observed crack velocity and fracture surfaces for Polymethyl Methacrylate (PMMA) specimens. In addition, we investigate the influence of the specimen size on the dynamic fracture process using two dimensional peridynamic simulations. The fracture strengths and the velocity toughening relationship obtained from different specimen sizes are compared with the Linear Elastic Fracture Mechanics (LEFM) size effect relationship and with results from experiments, respectively.

在骨折的动力学模型中，耗散的骨折能量在表示为力学视野的非局部区域上被规范化。本文使用二维和三维模拟在两个加载工况下带凹口的板中动态断裂扩展，研究了该参数对脆性固体中动态断裂过程的影响。在3D计算仿真中，将初始存储的能量在各种情况下的预测裂纹速度（也称为速度增韧行为）以及在不同裂纹扩展方式下获得的裂纹表面拓扑特征与实验观察到的裂纹速度和断裂进行比较聚甲基丙烯酸甲酯（PMMA）标本的表面。此外，我们使用二维周边动力学模拟研究了试样尺寸对动态断裂过程的影响。将不同试样尺寸获得的断裂强度和速度增韧关系与线性弹性断裂力学（LEFM）尺寸效应关系进行比较，并与实验结果进行比较。