Abstract Functionally graded materials are regarded as a special kind of composites capable of eliminating material interfaces and the delamination problems. Stress discontinuity can be avoided owing to smooth composition of the functionally graded ingredients. In this study, a recently emerged effective non-local continuum theory for solving fracture problems in solids and structures, peridynamics, is employed to simulate dynamic wave propagation as well as crack propagation in functionally graded materials. Specifically, the ordinary state-based formulation is adopted. The ordinary state-based formulation is slightly modified for the modelling of functionally graded materials. The averaging technique is employed to determine peridynamic parameters associated with the material properties. Firstly, a benchmark problem is considered to validate the present implementation of ordinary state-based peridynamics for brittle fracture of homogeneous materials. Then, the wave propagation in the functionally graded materials under impact loading is simulated. Finally, dynamic crack propagation in the functionally graded materials is studied. The evaluated crack paths and the displacement waves are compared with reference works including numerical and experimental results. Good agreement between the reference and present results is achieved. It is shown that a simple modification of ordinary state-based formulation has led to simulate dynamic fracture of functionally graded materials.

中文翻译：

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使用基于普通状态的近场动力学对功能梯度材料进行动态断裂分析

摘要 功能梯度材料被认为是一种能够消除材料界面和分层问题的特殊复合材料。由于功能分级成分的平滑组成，可以避免应力不连续。在这项研究中，最近出现的有效的非局部连续介质理论用于解决固体和结构中的断裂问题，近场动力学，用于模拟动态波传播以及功能梯度材料中的裂纹传播。具体来说，采用普通的基于状态的公式。对于功能梯度材料的建模，普通的基于状态的公式略有修改。采用平均技术来确定与材料特性相关的近场动力学参数。首先，一个基准问题被认为是为了验证基于普通状态的近场动力学对均质材料脆性断裂的当前实施。然后，模拟了冲击载荷下功能梯度材料中的波传播。最后，研究了功能梯度材料中的动态裂纹扩展。将评估的裂纹路径和位移波与包括数值和实验结果在内的参考工作进行比较。在参考结果和当前结果之间实现了良好的一致性。结果表明，对普通的基于状态的公式进行简单修改，可以模拟功能梯度材料的动态断裂。模拟了冲击载荷下功能梯度材料中的波传播。最后，研究了功能梯度材料中的动态裂纹扩展。将评估的裂纹路径和位移波与包括数值和实验结果在内的参考工作进行比较。在参考结果和当前结果之间实现了良好的一致性。结果表明，对普通的基于状态的公式进行简单修改，可以模拟功能梯度材料的动态断裂。模拟了冲击载荷下功能梯度材料中的波传播。最后，研究了功能梯度材料中的动态裂纹扩展。将评估的裂纹路径和位移波与包括数值和实验结果在内的参考工作进行比较。在参考结果和当前结果之间实现了良好的一致性。结果表明，对普通的基于状态的公式进行简单修改，可以模拟功能梯度材料的动态断裂。