摘要
采用直接热力耦合的方法,引入7075铝合金高温下的流变应力特征曲线,对不同厚度的7075铝合金板材在实际淬火工艺下的淬火过程进行数值模拟,揭示铝合金板材淬火残余应力分布规律;考虑铝合金板材拉伸过程中的实际夹持方式,对不同厚度7075铝合金板材实际拉伸过程进行数值模拟,分析对比拉伸后残余应力分布规律,并对拉伸工艺进行优化,确定最佳拉伸率和锯切量,揭示厚度变化对淬火残余应力、拉伸后残余应力以及锯切量的影响规律。利用钻孔法对实际拉伸的7075铝合金板材进行拉伸后残余应力的试验测试,数值模拟结果与试验测试结果相吻合。研究结果表明,随着厚度的增加,淬火残余应力、最佳拉伸率以及锯切量都相应增大,锯切量中过渡区长度为板材厚度的60%～70%。
By introducing the flow stress curve,the numerical simulation of stress redistribution during the quenching process for 7075 aluminum alloy plates with different thickness is performed using a direct thermo-mechanical coupled method.Considering the practical clamping,the stretching simulation of 7075 aluminum alloy sheets with different thickness is conducted to analyze the residual stress distribution.Also,the pre-stretching process is optimized to determine the stretch rate and the amount of cutting.Through the analysis,the influences of thickness variation on quenching-induced residual stresses,stretching residual stresses and the amount of cutting are investigated.A practical experiment was conducted to demonstrate the quenching-induced residual stresses distribution using a blind hole measuring method.The result which compares well with the simulation shows that the quenching-induced residual stress,stretch rate and the amount of cutting are increased as the aluminium alloy plate becomes thicker.The length of transition zone is about 60%～70 % of the thickness.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2011年第24期57-62,共6页
Journal of Mechanical Engineering
基金
科技特派计划资助项目(2009GJF10028)
关键词
残余应力
淬火
预拉伸
锯切量
厚度变化
Residual stress
Quenching
Pre-stretching
Amount of cutting
Thickness variation
