This study presents a peridynamic model with an improved energy-based surface correction to simulate fractures of random porous materials. There exists a surface effect due to incomplete neighborhoods of boundary or near-boundary points in peridynamics. A surface correction approach is proposed to correct the surface effect on or near the boundaries, including outer boundaries of the materials and boundaries of inner pores. The correction factor is obtained based on the equivalence between the strain energy density in classical continuum mechanics and the elastic energy density in peridynamics. The algorithm procedure for the corrected model based on the finite element analysis is brought forward in detail. The availability of the proposed corrected peridynamic model is verified by comparing the results against the results by the classical continuum mechanics model. Moreover, the effect of the surface correction on the crack growth path and the impact of random distributions of pores on the fractures of porous materials are also investigated. Numerical results demonstrate that the present method can effectively correct the surface effect of random porous materials, especially around the boundary of inner pores, where shows a more obvious surface effect.

这项研究提出了一种基于动力学的表面动力学模型，该模型具有改进的基于能量的表面校正，可以模拟随机多孔材料的断裂。由于周边动力学中边界点或近边界点的邻域不完整，因此存在表面效应。提出了一种表面校正方法来校正边界上或边界附近的表面效应，边界包括材料的外边界和内孔的边界。根据经典连续统力学中的应变能密度与周边动力学中的弹性能密度之间的等价关系获得校正因子。提出了基于有限元分析的修正模型的算法程序。通过将结果与经典连续力学模型的结果进行比较，可以验证所提出的修正后的动力学模型的可用性。此外，还研究了表面校正对裂纹扩展路径的影响以及孔的随机分布对多孔材料断裂的影响。数值结果表明，该方法可以有效地校正随机多孔材料的表面效应，尤其是内孔边界附近，表面效应更为明显。