考虑复杂界面特征的颗粒复合材料线弹性断裂力学行为研究

Fracture damage is one of the most common failure modes of particulate composites. The material interfaces are very complex in particulate composites and it is difficult to obtain fracture mechanics parameters effectively in the complex-interface environment for present fracture mechanics methods, which slow down the development of fracture mechanics study of particulate composites. Addressing the feature that the interfaces in particulate composites are very complex, this project aims to establish a domain-independent interaction integral model for material interfaces-DIIMI model, achieve the goal of effectively solving the fracture mechanics parameters-stress intensity factors and T-stress of particulate composites, and thus provide a theoretical foundation for linear-elastic fracture mechanics study of particulate composites. An efficient analysis method for simulating the linear-elastic fracture mechanics behaviors of particulate composites will be formed by combining the DIIMI model and the extended finite element method both of which have the ability to deal with material interfaces effectively. By a suitable selection of fracture criteria, the numerical analysis techniques mentioned above will be used to simulate the fracture process of particulate composites. The simulations will be compared with the experimental observations to improve the numerical analysis method. The research results of this project are significant for the linear-elastic fracture mechanics study of particulate composites and provide new ideas for further study of the fracture mechanics problems of the materials with complex interfaces.

断裂破坏是颗粒复合材料最常见的一种失效模式。颗粒复合材料内部的材料界面非常复杂，目前的断裂力学方法难以在复杂界面环境下有效获取断裂力学参量，这导致颗粒复合材料断裂力学研究进展缓慢。本项目针对颗粒复合材料内部界面非常复杂这一特征，拟建立对材料界面具有区域无关性的相互作用积分模型- - DIIMI模型，并实现DIIMI模型对颗粒复合材料断裂力学参量- - 应力强度因子和T应力的有效求解这一目标，为颗粒复合材料线弹性断裂力学行为研究奠定理论基础。将同样能够有效处理材料界面的DIIMI模型和扩展有限元方法相结合，为模拟颗粒复合材料线弹性断裂力学行为提供一套高效的分析方法。引入适当的断裂准则，利用上述数值方法模拟颗粒复合材料的断裂过程，并与实验进行对比，改进数值分析方法。项目的研究成果对颗粒复合材料的线弹性断裂力学行为研究具有重要意义，为深入研究含复杂界面材料的断裂力学问题提供了新的思路。

颗粒复合材料常作为结构材料或功能材料广泛应用于工程领域中，复杂的内部结构常导致该材料极易发生断裂破坏。然而，颗粒复合材料断裂力学研究却进展缓慢，其主要原因是现有的断裂力学方法难以有效获取含复杂界面材料的断裂参量。为了量化分析颗粒复合材料的裂纹扩展行为，本项目主要研究如何建立有效获取含复杂界面材料断裂参量的力学方法，主要包括：建立对材料界面具有区域无关性的I积分——DII积分；发展微极材料断裂基本理论及求解其断裂参量的力学方法；完善含复杂界面材料多物理场下断裂力学方法。