摘要
针对异形底难成形的问题,以异形底盒形件为研究对象进行了充液拉深有限元数值模拟研究。设计了先预胀后拉深的液压加载路径,对零件成形及贴模性进行有限元数值模拟研究。为了提高成形质量,采用施加主动周向压力的工艺方法,基于数值模拟技术,提出了通过设置局部坐标系来简化周向压力施加复杂的问题;设计了两种坯料形式,四组周向压力加载曲线。又对盒形件壁厚不变线不规则的问题,将板料变形后的形状映射在变形前的板料上,更加清楚地看出各个形状板料在不同周向压力下壁厚不变线的变化规律。模拟实验结果表明:主动径向压力的施加可以使壁厚不变线向盒形件底部下移,减少了减薄区域,提高了盒形件壁厚均匀性;同时提高了贴模性及尺寸精度;在主动径向加压充拉深成形过程中,圆形切弓形状板料相较于圆形板料能更好地成形出内凹底盒形件。
To solve the problem of difficult forming of irregular bottom,the finite element numerical simulation of hydro-filling deep drawing of special-shaped bottom box was studied.The hydraulic loading path of pre-expansion and deep drawing was designed,and the forming and die-sticking properties of the parts were simulated by finite element method.In order to improve the forming quality,the process of applying active circumferential pressure was adopted.Based on the numerical simulation technology,the complex problem of applying circumferential pressure was simplified by setting local coordinate system.Three blank forms and four groups of circumferential pressure loading curves were designed.Aiming at the irregular wall thickness invariant line of box-shaped parts,the shape of deformed sheet metal is mapped on the sheet metal before deformation,and the variation law of wall thickness invariant line of each shape sheet metal under different circumferential pressure is more clearly seen.The simulation results show that the application of active radial pressure can make the wall thickness invariant line move down to the bottom of the box,reduce the thinning area and improve the uniformity of the wall thickness of the box;at the same time,it improves the clamping property and dimensional accuracy;in the process of active radial pressure deep-drawing,the circular cut-bow shape sheet metal can be formed better than the circular and square cut-edge shape sheet metal concave bottom box.
作者
刘晓晶
李连峰
张晓华
潘景浩
LIU Xiao-jing;LI Lian-feng;ZHANG Xiao-hua;PAN Jing-hao(School of Material Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China)
出处
《哈尔滨理工大学学报》
CAS
北大核心
2021年第2期131-138,共8页
Journal of Harbin University of Science and Technology
基金
哈尔滨市创新人才基金(2017RAXXJ008)
国家自然科学基金(51305110).
关键词
预胀
壁厚不变线
数值模拟
主动周向加压
pre-expansion
wall thickness invariant line
numerical simulation
active circumferential pressure
