为解决大尺寸双曲率蒙皮拉伸成形过程中采用传统的经验法进行反复修模、试模,导致的研制周期长、效率低的问题,针对3种不同的拉伸成形工艺参数,采用AI-Form Stretch Forming(AISF)有限元软件进行板料拉伸成形模拟,探究了最佳拉伸成形工艺参数组合,预测了板料在拉伸成形过程中的应变分布情况.研究发现:当模具高度为1000 mm以及增大上模压力至100 k N时,拉伸成形的板料表面变形均匀,最大应变约为0.15,最大贴模间隙小于1 mm.通过工艺试验验证发现,试验与模拟结果较为吻合,最大误差小于2.8%,且能够有效地降低板料拉伸成形过程中的起皱.结果表明,最佳拉伸成形加载参数下能够获得质量较高的蒙皮零件,降低研制周期,提高生产效率.
Numerical simulation and process optimization on longitudinal stretch forming of complex large size skin
In order to solve the problem of long development cycle and low efficiency caused by repeated repair and testing of die when using traditional empirical method in the stretch forming process of large-size double-curvature skin,for three different stretch forming process parameters,the AI-Form Stretch Forming(AISF)finite element software was used to simulate the sheet metal stretch forming,and the optimal combination of stretch forming parameters was explored to predict the strain distribution condition of sheet metal during the stretch forming process.The results show that when the die height is 1000 mm and the upper die pressure is increased to 100 k N,the sur-face deformation of the stretch-formed sheet metal is uniform with the maximum strain of 0.15 and the maximum die clearance less than 1 mm.Through process testing verification,the experimental result is in good agreement with the simulation result with the maximum error of less than 2.8%,which effectively reduces the wrinkling during sheet metal stretch forming process.Thus,the results show that high-quality skin parts are obtained at the optimum stretching loading parameters,reducing the development cycle and improving the production efficiency.
large size skinstretch forming2A97 aluminum lithium alloydie heightupper die pressurestrain
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