基于数值模拟的弹性—蠕变双材料界面应力分析  

STRESS ANALYSIS AT THE INTERFACE OF ELASTIC-CREEP BI-MATERIAL BASED ON NUMERICAL SIMULATION

作　　者：陈清琦[1] 轩福贞[1] 涂善东[1] 

机构地区：[1]华东理工大学机械与动力工程学院,上海200237

出　　处：《机械强度》2009年第3期497-502,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金(50505012);上海市青年科技启明星计划(05QMX1416);霍英东青年教师基金(101054)~~

摘　　要：利用ABAQUS大型有限元程序,对比分析线弹性和蠕变两种情况下Silicon/epoxy弹性—蠕变双材料界面应力分布问题。分析结果表明,界面边缘处存在严重的剪应力和剥离应力集中;边缘对齐结构的界面剪应力和剥离应力集中要小于边缘不对齐的情况;随着基体厚度增大,界面剪应力和剥离应力均减小;当基体与薄膜的厚度比增大到临界值时,剥离应力将反向,此时剥离应力的绝对值随着厚度比的增大而增大;蠕变会导致界面边缘附近剪应力和剥离应力松弛,且薄膜的蠕变指数和系数越大,蠕变松弛效应越明显,随时间增大,边缘附近界面上的应力逐渐趋近于零。By using the general finite element program of ABAQUS, a comprehensive stress analysis at interface of Silicon/epoxy elastic-creep hi-material is performed under the conditions of elastic and creep. Results indicated that the interfacial shear and peeling stresses are highly concentrated near the edge of structures. The stress concentration near the edge of FE（finite element） model is clearly affected by the geometrical shape and size. On the one hand, the stress concentration of aligned edge is lower than that of the no-aligned edge. On the other hand, the strain mismatch between the film and substrate is related to the thickness of substrate. With the increasing thickness of substrate, the interfacial shear and peeling stresses decreases. When the ratio of thickness reaches the critical value, the direction of peeling stress will reverse and then its absolute value increases with the increasing ratio of thickness. Under the creep condition, the value of interfacial shear and peel stresses near the edge of structure will reduce due to the relaxation. Moreover, decrease of stress will enlarge with the increasing creep exponent and creep coefficient of film. Consequently, the stress concentration near the edge of structure will vanish with the creeping time extension.

关 键 词：双材料结构 蠕变 界面应力 有限元 

分 类 号：O346[理学—固体力学] TB131[理学—力学]