摘要
采用有限元方法分析了钎焊搭接SnAgCu-CNT焊点在125^-40℃温度循环载荷条件下的蠕变应变和应力分布。结果表明,经过4个温度循环周期后,SnAgCu-CNT搭接焊点发生了明显的剪切变形,产生了显著的上下表面相对位移。焊点的最大等效蠕变应变位于焊点与焊盘界面边缘沿长度方向上的中点处,最小蠕变应变位于焊点的中心处。有限元的计算结果与实际热循环试验的结果相一致。最大蠕变应变节点的蠕变应变和应力随时间变化的曲线呈现出明显的周期性和累积效应。
Distribution of creep strain and stress of SnAgCu-CNT lap shear solder was studied under conditions of 125-40 ℃ by means of finite element method(FEM). The results show that obvious shearing deformation is found on the lap solder after 4 thermal cycles, then is the visible displacement on the upper and lower surfaces. Maximum equivalent creep strain lies in the middle of length orientation of solder-pad surfaces, while minimum strain lies in the center of solder. FEM results coincide well with experiment results. The curve of equivalent creep strain and stress versus time in the node of maximum equivalent creep strain exhibit apparent periodicity and build-up effect.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2007年第11期85-88,92,共5页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(50575160)
博士点基金资助项目(20050056035)
