摘要
板料在冲压成形过程中经常出现起皱、鼓包及拉裂等缺陷。板料成形过程包括了非常复杂的物理现象 ,涉及力学中的几何非线性、物理非线形和边界非线性 ,很难用解析法研究。利用大型非线性有限元软件ANSYS/LS -DYNA ,对板料拉深过程进行了数值模拟 ,分析了成形后可能发生的缺陷 ,讨论了冲压速度、摩擦系数及压边力等因素对板料成形质量的影响。结果表明 ,凸模和凹模交界处的板料首先变形 ,应力及应变最大值出现在凸模圆角部位外侧板料上。板料凸缘增厚量最大 ,凹模圆角处板料减薄量最大 ;凸模与板料间摩擦系数越大 ,边缘应力越大 ,板料凸缘越不易起皱 ,而侧壁应力受凸模与板料间摩擦系数的影响较复杂 ;适当的增加凸模虚拟模拟速度可以提高计算效率 。
In the process of forming, the sheet often appearscrinkle?bloating and rip. The sheet's forming process includescomplex physical phenomena such as non-linear of geometry?material and boundary, so it is very difficult to be solved by means of analytic method. Numerical simulation of sheet metal drawing was made by means of ANSYS/LS-DYNA and the position of potential flaw was forecast. At the same time, the factor of infecting sheet's forming, punching velocity, fiction coefficient and press force were discussed. The results show that the sheet in the adjacent area of die and punch deforms primarily. The maximal value of stress and strain appears in the sheet of outboard punch round corners. The maximal bodiness is sheet flange and the maximal attenuateis the sheet of die round corners ; The more fiction coefficient between die and punch the brim stress is great and the wrinkle isn't easily emergent in the rim of sheet; The effect of fiction coefficient on parietal stress is complex. Enhancing punch velocity properly not only boosts efficiency of operation but also assures precision of calculation.
出处
《辽宁省交通高等专科学校学报》
2005年第1期44-46,共3页
Journal of Liaoning Provincial College of Communications
