层状磁电弹半柱中同轴界面上的裂纹相互作用规律

Interaction between Cracks on Coaxial Interfaces in a Layered Magnetoelectroelastic Semicylinder

针对"磁电弹-正交基体-磁电弹"3层半柱结构中2个同轴界面同时开裂的问题,建立了其断裂力学理论模型。运用位错模拟法和Green函数法,推导了裂纹问题的奇异积分方程组,并得到了应力强度因子的数值解。基于参数分析,讨论了层厚和裂纹的环向相对位置对应力强度因子的影响规律,阐明了其中的刚性边界效应、自由边界效应、屏蔽效应和干涉效应,揭示了屏蔽与干涉相互竞争所引起的局部区域内应力强度因子的特殊振荡现象。相关结论可为层状磁电弹智能器件的防断裂优化设计提供理论参考。

Fracture mechanics theoretical model is established aiming at the problem of multiple unequal coaxial interfaces cracking simultaneously in tri-layered smart semicylinder consisiting of an intermediate orthotropic substrate and two magnetoelectroelastic layers.Both the methods of dislocation simulation and Green's function are employed to derive the singular integral equations,from which the numerical solutions of Stress Intensity Factor(SIF) are further obtained.Then,based on parametric studies,the effects of layer thickness and circumferential relative positions of cracks on SIF are discussed;the stiff-boundary effect,free-boundary effect,shielding effect and interference effect are clarified;and the special local oscillatory phenomenon of SIF induced by competition between the shielding effect and interference effect are also revealed.The research conclusions can serve as references for the fracture-proof optimal design of layered magnetoelectroelastic smart devices.