应力松驰对估算锡晶须生长的影响  

THE EFFECT OF STRESS RELAXATION ON WHISKER GROWTH ESTIMATION

作　　者：强磊[1] 黄再兴[1] 萧业 高军[1] 

机构地区：[1]南京航空航天大学机械结构力学及控制国家重点实验室,南京210016

出　　处：《机械强度》2015年第5期935-939,共5页Journal of Mechanical Strength

基　　金：航空科学基金(20080252);江苏高校优势学科建设工程项目资助~~

摘　　要：为了描述锡晶须生长过程中的应力生成与应力松驰同时发生的特性,对弹塑性-蠕变本构模型采用返回映射算法,在Abaqus平台上,通过自编的UMAT子程序进行求解。有限元计算表明,与Abaqus自带的弹塑性模型相比,弹塑性-蠕变模型能够有效的反映材料的应力松驰行为。应用该程序,我们计算了无铅焊试样中应力的变化,根据应力的变化估算了锡晶须的生长率,并研究了晶粒尺寸对锡晶须生长率的影响。To describe the phenomenon of the stress generation and stress relaxation occurring simultaneously in the process of whisker growth, a UMAT subroutine in Abaqus is developed to solve the elasto-plastic creep constitutive model by means of the return-mapping algorithm. The finite element simulations show that, compared with the elasto-plastic model in Abaqus, the elasto-plastic creep constitutive model characterizes the stress relaxation of material better. Using this subroutine, we calculate the change of stress in a specimen of Pb-free solder. In terms of the change of stress, the whisker growth rate is evaluated. And the effect of the grain size on the whisker growth rate is discussed.

关 键 词：锡晶须 应力松驰 返回映射算法 弹塑性-蠕变本构模型 

分 类 号：O34[理学—固体力学]