汽车结构件内高压成形应力极限分析  

Investigation of forming stress limit in tube hydroforming of automobile framework

作　　者：周林[1] 程晓民[1] 薛克敏[2] 李萍[2] 杨文江[3] 崔礼春[3] 

机构地区：[1]宁波工程学院机械工程学院,宁波315016 [2]合肥工业大学材料科学与工程学院,合肥230009 [3]安徽江淮汽车集团汽车技术研究院,合肥230033

出　　处：《塑性工程学报》2008年第5期95-100,共6页Journal of Plasticity Engineering

基　　金：宁波市自然科学基金资助项目(2006A610028);安徽省"十一五"科技攻关资助项目(06012150C)

摘　　要：由极限应力构成的应力成形极限图(FLSD)独立于应变路径,可作为复杂应变路径下成形极限的判据。通过标准成形极限实验获得3A21铝合金板材的成形极限图(FLD);由极限应力应变转换关系,将极限应变转换至主应力空间,建立对应的FLSD;采用LS-DYNA软件对方截面汽车结构件内高压成形过程进行了模拟,应用FLSD预测胀形过程中破裂的发生及极限成形压力。模拟结果与物理实验结果相吻合,证明FLSD可作为管材内高压成形等复杂应变路径下成形极限的判据。The forming limit stress diagram （FLSD） which established with limit stress is independent on the strain paths and it is practical to use as the criterion of forming limit under cmplex strain paths. The forming limit of 3A21 Aluminum alloy sheet was tested and the forming limit diagram （FLD） was determined. Then the FLSD of 3A21 was constituted by transformation formu- las between limit strain and limit stress. This FLSD was used in conjunction with LS-DYNA finite element simulation to predict the onset of fracture and limit forming pressure in tube hydroforming. The simulation result compares well with the experimental result. The FLSD is able to predict the forming limit of tube hydroforming with remarkable accuracy.

关 键 词：内高压成形 破裂缺陷 应力成形极限图 数值模拟 

分 类 号：TG386.43[金属学及工艺—金属压力加工]