——焊点失效的主控力学因素
(1. 哈尔滨工业大学 现代焊接生产技术国家重点实验室， 哈尔滨 150001；
2. 广岛大学 工学部弹塑性工学研究室， 日本， 739)
摘 要: 温度循环载荷可以在焊点界面处形成足以导致空洞损伤发生的高应力三轴度。 针对温度循环载荷下软钎焊焊点界面空洞损伤的失效行为特点，结合焊点内部应力—应变场分布特征及其温度历史相关性， 提出了相对损伤应力这一概念，并以此作为温度循环载荷下软钎焊焊点失效的主控力学因素。分析了温度历史不同阶段对焊点失效行为的影响，结果表明高温保温阶段焊点内部最容易发生空洞损伤。
关键字: 相对损伤应力； 主控力学因素； 空洞损伤；温度历史
characteristics in SMT solder joints(Ⅱ)
——Dominant mechanical factor responsible for failure of solder joint
（1. National Key Laboratory of Welding, Harbin Institute of Technology, Harbin 150001, P.R.China;
2. Department of Mechanical Engineering, Hiroshima University, HigashiHiroshima, 739, Japan）
Abstract:Interface void damage is the failure characteristic of solder joint under temperature cycling. Based on the distribution feature and temperature history relativity of stressstrain field in the solder joint, the concept of relative damage stress was put forward as dominant mechanical factor responsible for the failure of solder joint. Analysis results showed that it is easiest for void damage to occur in the high temperature holding time during temperature cycling history.
Key words: relative damage stress； dominant mechanical factor； void damage； temperature history
