【作者】 刘宝荣；

【导师】 宋天舒；

【作者基本信息】 哈尔滨工程大学 ， 结构工程， 2009， 硕士

【摘要】 压电材料在智能材料中使用非常广泛,例如力电传感器,传输器和执行器,因为它们有较好的力电耦合特性。本文采用有限元法研究双相压电介质中近场椭圆形孔洞对瞬态SH波的散射和动应力集中问题。有限元法在数学上是将偏微分方程的初边值问题划归一组常微分方程的初值问题或一组规则代数方程。然后,用NEWMARK直接积分进行求解,得到各节点和单元的位移、应力的时程解。用有限元模拟波动问题,其首要问题是人工边界的设置问题,由于要从无限域中截取有限区域来模拟无限域,所以要引入人工边界。其次是解决时空离散带来的各种影响,以减少误差。还要考虑荷载的施加问题以及模型大小对解题的影响问题。本文对要解决的问题建立了有限元模型,并用通用有限元分析软件ANSYS进行计算,给出了部分节点的位移、应力时程解和孔边动应力集中系数,并对结果进行了讨论。本文的具体工作如下：研究了瞬态SH波入射到双相压电介质中界面上椭圆孔引起散射时,讨论的是在上部压电介质不同时和长、短轴比变化时对应力、位移和动应力集中系数影响；并且研究了瞬态SH波入射到双相压电介质中界面附近含椭圆孔引起散射时,讨论的是在上部压电介质不同时对应力、位移和动应力集中系数影响。更多还原

【Abstract】 Piezoelectric materials have been more and more widely used in smart matrials such as electromechanical sensors, transducers and actuators due to their strong electromechanical coupling characteristics. The present thesis investigates the scattering problems and the dynamic stress concentration problems of SH-wave by ellips cavities in near field by the method of FEM.The FEM is a method of which transform the partial differential-coefficient equation’s initial and boundary value issue to ordinary differential-coefficient equation’s initial an boundary value problem or a set of regular algebra equation.Then,use the direct integral calculus method of NEWMARK to solve solution,and get each node and element’s displacement and stress vs. time.There are two problems in simulation SH-wave issue by finite element method.The first is establishing artificial boundary problem,because of simulating the infinite field from the finite field in which intercept from the infinite field,so we introduce in space-time dispersing to reduce error.In additional,the problems of load’s infliction an model’s size should be considered.In this article,we found the finite element model in allusion to the problem above,solved the equation by the general finite element analysis software ANSYS,gave some node’s displacement and stress solution vs.time and the dynamic stress concentration at edge of cavity,discussed the result.The present work is mainly as follows:Scattering of transient SH-wave and dynamic stress conceatration problem are investigated by interface ellipse cavities in two dissimilar piezeoelectric media.The influence on stress and displacement and dynamic stress concentration of different piezeoelectric media and the cavities’radius are discussed. Then,Scattering of transient SH-wave and dynamic stress conceatration problem are investigated by an elliptic cavity in two dissimilar piezeoelectric media.The influence on stress and displacement and dynamic stress concentration of different piezeoelectric media is discussed.更多还原