摘要
考虑了温度改变对高聚物材料体积变化的影响,将材料的不可压缩假定修正为可压缩假定.对具有neo-Hookea特征的高聚物电子封装材料在回流焊过程中由于湿热所引发的"爆米花"式的孔穴破裂现象进行了理论研究.利用有限变形的理论给出此类材料在计及体积改变效应下的孔穴增长和吸湿产生的蒸气压力与热应力之间的广义解析关系.该广义解析关系包含了不可压缩条件下的解析关系.分析结果表明:当温度改变引起的可压缩效应较大时,利用可压缩假定分析得到的极限载荷值与利用不可压缩假定分析得到的极限载荷值相比有所提高.但当温度改变引起的可压缩效应较小时,利用两种假定分析得到的极限载荷值相差不大.在温度变化范围不大的情况下,采用不可压缩的假定是合理的.
The assumption of materials＇ incompressibility was amended to compressibility when the effect of temperature change on the volume of polymer materials was taken into account.Theoretical analysis of the popcorn void crack in the neo-Hookea polymer materials undcr the effect of hygro thermal during reflow soldering was achieved.Based on finite deformation theory,a general analytical solution relating the void growth to the vapor presser and thermal stress was obtained when the volume of material changes due to temperature.The general analytical solution included the analytical solution of the incompressible material as a special case.The analysis results showed that,taking the effect of volume expansion of polymer materials into account,the critical load would be increased.If the expansion coefficient is smaller,the effect of volume expansion on the evolution of the void will be less.Therefore,the incompressible hypothesis is reasonable when the temperature variation range is small.
出处
《固体力学学报》
CAS
CSCD
北大核心
2013年第5期487-492,共6页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金资助项目(11172195)
山西省自然科学基金(2012011019-4)资助
