高强度钢板冲压模具强度分析与结构优化

发布时间：2018-02-21 04:21

本文关键词： 高强度钢板压型模具结构优化载荷转换　出处：《湖南大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着人们对汽车的轻量化与安全性能提出更高的要求,高强度钢板正逐渐成为汽车覆盖件的首选材料。高强度钢板具有强度高和塑性低的特点,相比普通钢板,高强度钢板更易造成模具磨损,因此对冲压模具的结构形式提出更高的要求。目前,冲压模具结构在设计时仅依赖于模具设计人员的经验,缺乏可靠准确的分析方法。故其设计时往往忽略了模具的弹性变形,难以精确获得模具的受力情况及板料的成形质量。因此,本文将提出一种新的模具结构优化方法——考虑模具弹性变形,将拓扑优化技术与板料成形数值技术相结合,对模具的结构形式进行优化分析。首先运用LS-DYNA软件建立模具弹塑性的有限元冲压仿真模型,以获得冲压过程中板料对模具的作用力。通过板料成形极限分析以及冲压过程的应力应变结果对传统模具的受力及变形情况进行了全面准确的预测。其次通过载荷转换成功地将数值模拟成形过程中的接触力加载为拓扑优化模型的力边界条件。运用OPTISTRUCT软件对冲压模具进行拓扑优化,并结合汽车覆盖件的铸造工艺特点对优化后的结构进行几何重构。最后将优化前后模具结构的动力分析结果进行对比分析,新结构比传统结构节约重量约26.4%,模具最大应力降低48.3%,最大应变降低64.5%。表明了该模具结构优化方法的有效性。
[Abstract]:High strength steel plate is becoming the first choice material of automobile panel with higher requirement of light weight and safety performance. High strength steel plate has the characteristics of high strength and low plasticity, compared with ordinary steel plate, high strength steel plate is becoming the preferred material for automobile panels. High strength steel plate is more likely to cause die wear, so higher requirements are put forward for the structural form of stamping die. At present, the design of stamping die structure only depends on the experience of the die designer. Because of the lack of reliable and accurate analysis methods, the elastic deformation of the die is often neglected in its design, and it is difficult to accurately obtain the stress of the die and the forming quality of the sheet metal. In this paper, a new method of die structure optimization is proposed. Considering the elastic deformation of die, the topology optimization technique is combined with the numerical technology of sheet metal forming. The structure of die is optimized and analyzed. Firstly, the finite element stamping simulation model of die elastoplasticity is established by using LS-DYNA software. Through the forming limit analysis of sheet metal and the stress and strain result of stamping process, the stress and deformation of traditional die are forecasted comprehensively and accurately. The contact force in the process of numerical simulation is successfully loaded into the force boundary condition of the topology optimization model. The stamping die is topologically optimized by using OPTISTRUCT software. The geometric reconstruction of the optimized structure is carried out according to the casting process characteristics of the automobile panel. Finally, the dynamic analysis results of the die structure before and after the optimization are compared and analyzed. Compared with the traditional structure, the new structure saves about 26.4 weight, reduces the maximum stress of the die by 48.3% and the maximum strain by 64.55.This shows the effectiveness of the optimization method of the die structure.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U466

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