高速冲击破坏的近场动力学与连续介质力学耦合模型及其算法研究

A high speed impact failure is a dynamics problem with nonlinearity. Under a high speed impact loading, the material near the contact point responds vigorously, such as large deformation and fragmentation, in a very short period of time, whereas the material away from the contact point responds with a smaller strain state. Therefore, a simulation of high speed impact failure faces significant challenges, such as high computational cost, synchronous propagations of massive cracks and multi-timescale responses in one material. This project will carry out coupling modeling and numerical method studies on fundamental science problems in the simulation of high speed impact failure, by combining novel peridynamics and classical continuum mechanics. The main research contents include: developing coupling models between non-ordinary state-based peridynamics and continuum mechanics; establishing dynamic fracture criterion of peridynamic bonds; developing a multi-time-step algorithm for adaptive domain decompositions and developing the relavant software function modules. The main objective of the project is to propose a systematic solution from four aspects including theoretical modeling, failure criterion, numerical method and software development, aimed at particularity of high speed impact failure, for providing valuable knowledge and strong supports to relevant academic researches and national important demands.

高速冲击破坏是非线性动力学问题。在高速冲击载荷下，材料在接触点局部短时间内发生剧烈响应，如大变形和碎裂，而在远离接触点的地方材料处于较低的应变响应状态。因此，模拟高速冲击破坏需要面对计算量巨大、局部巨量裂纹同步扩展以及材料具有多时间尺度响应等重大挑战。本项目将围绕高速冲击破坏模拟中涉及的基础科学问题，结合新兴的近场动力学与传统的连续介质力学，开展耦合建模和数值方法研究。研究内容包括发展耦合非常规态型近场动力学与连续介质力学的新模型；建立近场动力学的动态“键”断裂准则；发展适用于自适应区域分解的多时间步长算法以及开发相应的软件功能模块。项目的研究目标是针对高速冲击破坏的特殊性从理论建模、破坏准则、数值方法和软件开发四个方面着手提出系统性的解决方案，为涉及高速冲击破坏模拟的学科前沿研究和国家重大需求提供有价值的参考和强有力的技术支持。

面向高速冲击条件下结构及其材料的破坏过程，本项目深入研究了近场动力学及其与连续介质力学的耦合模型和高效能算法；发展了适用于模拟高速冲击破坏的耦合模型和动态断裂准则；在数值实现层面开展了高效的多时间步长算法研究；基于我国自主知识产权的大型CAE生态化软件平台Genvi，将本项目提出的先进算法与代码集成到该平台，开发出了具有自主知识产权的近场动力学软件。在国际顶级和知名的计算力学或断裂力学期刊上发表学术论文12篇；申请技术发明专利2项，其中国际专利1项；申请软件著作权10项；在国际著名的计算力学大会上做学术报告2次，收到国内外同行的广泛关注。相关理论成果为近场动力学软件的国产化奠定了坚实的基础，相关软件成果在面向结构及其材料的断裂问题分析中具有广阔的应用前景。