电磁固体表面Maxwell应力对固体断裂的效应

Using theoretical and experimental approaches together with macroscopic and microscopic analyses, this project is focused on studying the fracture behaviors of electromagnetic solid subjected to surface Maxwell stresses. In theoretical research, emphasis is on the investigation of effects of Maxwell stresses on the fracture of the solid which is under electric or magnetic fields, mechanical-electric-magnetic coupling fields, and dynamic electromagnetic fields, respectively; in addition, the influences of micro-structure evolution on fracture is also taken into account. In experimental research, stress is on the fracture tests of electromagnetic solids, in order to explore the effects of Maxwell stresses at the interface of a bimaterial system. Novel points in this project include: several new crack models, for example, "Coulomb-bridging-crack" and "variable capacitor" models are proposed, which are expected to be used for explaining the energy dissipation mechanism in electromagnetic solids. Through the above theoretical and experimental works, the outcomes can be used to explore the failure mechanism of electromagnetic solids, to develop the fracture mechanics of electromagnetic materials, to establish the macro-micro fracture criterion, and finally to lay a theoretical foundation of reliability design for electromagnetic devices.

应用理论和实验相结合、宏观分析与微观分析相结合的方法,研究电磁固体在 其表面Maxwell 作用下的断裂行为。在理论研究方面，重点研究电磁固体分别在电磁场作用 下，在力-电-磁耦合载荷作用下、在动态电磁场作用下固体表面Maxwell 应力对断裂的效应； 同时考虑材料的微结构演化对裂纹扩展的影响。在实验研究方面，重点进行电磁材料在电磁 场作用下的断裂实验，探索不同材料界面上Maxwell 应力的效应。创新点包括：提出"Coulomb 裂纹桥"和"可变电容器"裂纹模型等，从而可望揭示在电磁场作用下电磁固体内部能量耗 散的机理。通过上述研究，加深人们对电磁固体断裂失效机理的认识，发展电磁固体断裂力 学理论，建立宏-微观断裂失效准则，为智能器件的可靠性设计奠定理论基础。

本项目应用理论和实验相结合、宏观分析与微观分析相结合的方法,研究电磁固体在其表面Maxwell应力作用下的断裂行为。在理论研究方面，重点研究电磁固体分别在电磁场作用下，在力-电-磁耦合载荷作用下、在动态电磁场作用下固体表面Maxwell应力对断裂的效应；同时考虑材料的微结构演化对裂纹扩展的影响。创新点包括：研究了压电体中MAXWELL应力对三维断裂问题的影响和表面效应对纳米孔洞/夹杂的影响，揭示了在电磁场作用下电磁固体内部能量耗散的机理。发展了电磁固体断裂力学理论，建立宏-微观断裂失效准则，为智能器件的可靠性设计提供了理论基础。