摘要
基于有限元软件MSC.Marc,对7075铝合金厚板淬火过程和预拉伸过程进行参数化模拟。以淬火残余应力作为初始条件读入预拉伸模型,利用生死单元技术,对预拉伸机夹具的夹紧和放松进行模拟,并对拉伸机理进行研究。研究结果表明:在拉伸过程中,表层金属应力由受压逐渐变为拉应力,而内层金属一直受拉应力作用,松开夹具后,铝合金厚板回弹,应变出现松弛,应力大大减小;随着拉伸量的增加,残余应力随之减小;而塑性变形随之增加;当拉伸量相同时,残余应力随铝合金板厚的增加而增加,为达到消除残余应力的最佳效果,预拉伸量需随板厚的增加而增加;在满足应力消除效果的前提下,拉伸量应取较小值。
The quenching and pre-stretching process of 7075 aluminum plates were simulated by MSC.Marc FEA program.The quenched residual stress was used as initial condition to apply on the pre-stretch model.The clamp and release of the clamp of pre-stretch machine were simulated using life and death element,and the pre-stretch mechanism was researched.The results show that the stress of the surface metal is changed from compress stress to tensile stress and the center metal stress suffers tensile stress all along in the process of the pre-stretch.When the clamp is released,the aluminum alloy thicken-plate is spring back,the strain is loosen and the stress diminishes greatly.The stress is diminished and the plastic deform is increased along with the increases of stretch value.The residual stress is increased with the increase of thickness of the aluminum alloy plate when the different plates have the same pre-stretching value.In order to diminish efficiently the residual stress,the pre-stretch value should increase with the increase of thickness of the aluminum alloy plate.The pre-stretch value should adopt the small value when the residual stress is diminished.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2011年第8期2303-2308,共6页
Journal of Central South University:Science and Technology
基金
国家重点基础研究发展计划("973"计划)项目(2005CB623708
2010CB731703)
关键词
铝合金厚板
预拉伸
残余应力
有限元法
参数化数值分析
淬火
aluminum alloy thicken-plate
pre-stretching
residual stress
finite element method
parametric numerical simulation
quenching
