离散压边冲压成形性能的数值模拟研究

发布时间：2018-06-01 15:12

本文选题：冲压成形 + 离散压边　；参考：《吉林大学》2016年硕士论文

【摘要】：冲压成形作为板料成形领域应用最广的一类生产工艺,具有制件美观、尺寸稳定、生产率高等一系列优点。对于市场上大多数冲压件,拉深过程中通常需要设置压边装置配合模具完成零件的成形,压边形式以及压边力设置合理与否显著影响其成形性能。整体压边工艺可以保证形状简单的零件的成形性能,而由于形状复杂的零件材料流动复杂,变形程度不一致,易导致起皱、破裂等缺陷产生。随着复杂曲面零件和各种高强度材料的面世,整体压边工艺已难以保证其成形性能。在压边装置设计中融入多点成形中的离散化思想,可以将传统冲压工艺中的整体压边圈离散化,使用相互独立的压边块进行有序组合,作为通用的离散压边装置。通过对不同变形区域压边力大小的合理调整,可有效改善起皱、破裂等缺陷,提高成形性能。本文主要研究内容和结论如下:1、建立有限元数值模拟模型建立了盒形件在整体压边和离散压边两种压边工艺时的有限元模型和复杂曲面件离散压边有限元模型,对边界条件、接触设置及网格划分等对计算结果有显著影响的设置进行了详细讨论。2、盒形件整体压边和离散压边成形性能对比分析从厚度分布和成形深度等角度对两种压边工艺成形性能进行了对比分析。同等成形深度下,两种工艺成形后的零件厚度分布差异较小;最大成形深度方面,离散压边成形深度达到80mm,与整体压边相比提高了一倍,证明离散压边工艺通过调整压边力分布可以有效提高成形性能。3、工艺参数对深拉深盒形件离散压边成形性能的影响分析探究离散压边工艺成形深度为70mm的盒形件时,坯料尺寸和形状、坯料和柔性压边圈间摩擦系数以及柔性压边圈厚度对成形性能的影响。成形深度较大时,坯料尺寸和形状、坯料和柔性压边圈间摩擦系数对盒形件成形性能的影响较为显著,柔性压边圈厚度对盒形件成形性能的影响较小。4、复杂曲面件离散压边冲压成形性能研究利用数值模拟方法探究复杂曲面件采用离散压边工艺时的成形性能。通过综合考量各因素成形结果,经过不断调整参数,得到了采用离散压边工艺的优化数值模拟成形结果,并对该成形结果进行了数值模拟结果验证,证明离散压边工艺可有效提高复杂曲面件的成形性能。
[Abstract]:As the most widely used production technology in sheet metal forming, stamping forming has a series of advantages, such as beautiful parts, stable size, high productivity and so on. For the majority of stamping parts in the market, it is usually necessary to set the blank holder device to complete the forming of the part with the die during the drawing process, and the shape of the blank holder and the setting of the blank holder force have a significant effect on the forming performance of the blank holder. The integral blank pressing process can guarantee the formability of the parts with simple shape, but because the material flow of the parts with complicated shape is complicated and the degree of deformation is not consistent, the defects such as wrinkling and cracking are easy to occur. With the appearance of complex curved surface parts and various high strength materials, it is difficult to guarantee the formability of the whole blank holder technology. The idea of discretization in multi-point forming can be incorporated into the design of the blank holder, and the integral blank holder can be discretized in the traditional stamping process, and the mutually independent blank holder can be combined in an orderly manner, which can be used as a general discrete blank holder. Through the reasonable adjustment of the blank holder force in different deformation regions, the wrinkling and cracking defects can be effectively improved and the formability can be improved. The main contents and conclusions of this paper are as follows: 1. The numerical simulation model of finite element is established. The finite element model of the box-shaped parts in the whole and discrete blank holder processes and the discrete blank holder finite element model of complex curved parts are established, and the boundary conditions are also discussed. This paper discusses in detail the setting of contact setting and mesh generation, which have a significant influence on the calculation results. The comparison and analysis of the overall and discrete blank holder formability of box-shaped parts from the angle of thickness distribution and forming depth are carried out to analyze the two kinds of blank holder workpieces from the point of view of thickness distribution and forming depth. The formability was compared and analyzed. At the same forming depth, the difference of the thickness distribution between the two processes is small. In the maximum forming depth, the discrete blank holder depth is 80 mm, which is twice as high as that of the whole blank holder. It is proved that the discrete blank holder process can effectively improve the formability by adjusting the distribution of the blank holder force, and the influence of the process parameters on the forming performance of the discrete blank holder of deep drawing box parts is analyzed. When the forming depth of the discrete blank holder process is 70mm, it is found that the forming depth of the discrete blank holder is 70mm. The influence of the size and shape of the blank, the friction coefficient between the blank and the flexible blank holder ring and the thickness of the flexible blank holder ring on the formability. When the forming depth is high, the size and shape of the blank and the friction coefficient between the blank and the flexible blank holder ring have a significant effect on the forming properties of the box parts. The influence of the thickness of the flexible blank holder on the formability of box parts is small. 4. The research on the forming performance of complex curved parts with discrete blank holder using numerical simulation method is carried out to explore the formability of complex curved parts with discrete blank holder. After considering the forming results of various factors and adjusting the parameters continuously, the optimized numerical simulation results using discrete blank holder process are obtained, and the results are verified by the numerical simulation results. It is proved that the discrete blank holder process can effectively improve the formability of complex curved surface parts.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG386

【参考文献】