【作者】 杜亭；

【导师】 柳玉起；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2004， 硕士

【摘要】 近年来,板料成形的有限元模拟技术已被广泛应用到产品设计开发中,很多企业都开始采用数值方法检查零件的可成形性,预测零件的开裂、起皱、回弹等缺陷,优化成形工艺参数,提高零件的成形工艺性。因此开发性价比高、能够满足企业用户需要的板料成形有限元模拟系统,具有非常高的实际应用价值及市场潜力。本课题由国家自然科学基金重点项目和教育部科学技术研究重点项目联合资助,是“大型复杂模具智能化仿真设计集成系统的研究开发”的重要组成部分。主要针对板料成形模拟问题,在核心算法的基础上,运用系统分析方法建立系统的框架,采用面向对象的设计方法,进行总体设计、数据结构设计、数据流图分析和设计。并对系统前后置处理模块中的一些关键技术进行了研究,针对图形变换、真实感图形显示和图元的动态拾取等方面做了比较深入的探索。建立了基于 Phong 光照模型的真实感光照绘图环境,使用简单,计算速度快,显示效果逼真,满足了软件系统图形显示的要求。在理论研究和系统设计的基础上,开发了完整意义上的面向工艺设计人员的金属板料成形有限元模拟 FASTAMP 软件系统,包括前置处理、求解器和后置处理三大模块:1) 前置处理模块包含了兼容性极高的 IGES 和 VDA 数据交换转换接口,高质量 的快速曲面网格生成器,丰富强大的点/线/曲面/单元编辑功能。2) 简单实用的后置处理模块可用于观察和评估金属冲压成形过程模拟计算的最 终计算结果,主要包括冲压件的厚度变化、应力-应变分布情况、冲压件的皱 曲和破裂情况、拉延筋的阻力效应、坯料的初始形状设计以及各种物理量沿 特定截面的变化趋势等。3) 基于逆算法的求解器能够完成板料冲压成形模具设计与成形性校核,为模具 工艺方案选择、模具结构设计、工艺参数优化提供快速有效的数值分析,也 可以应用于冲压件的可成形性快速模拟。精确反算冲压件或零件的坯料形状; 快速预测冲压件的厚度分布、应变分布、破裂位置、起皱位置等;精确真实 地模拟摩擦、压边力、拉深筋、背压力(托料力)等工艺参数,可以考虑压边 圈、顶柱器、曲压料面的作用情况。更多还原

【Abstract】 Finite element simulation technology of Sheet forming has been widely used in cycleof product design in recent years. It can help to simulate the stamping process oncomputer and find design problems before die manufacturing. If a low-price finite elementsimulation system can be developed and actually meet the practical needs of automobileindustry, it can be predicted that civil automobile industry will be more competitive andstronger by widely using finite element simulation method. The work of this paper is the important part of the project “research and developmentof integrate system for complex die & module intelligent design”, which is based on keyproject of Natural Science Foundation of China and science & technology researchprogram of MOE (ministry of education), People Republic of China. In this paper, the author studied the relative technology to construct the fully sheetmetal forming simulation system and founded the structure of the sheet metal formingsimulation system by using system analysis method and Object-oriented design methodbased on the inverse-approach-based analysis power. The system design, data structureand data flow diagram are also studied to build the Pro- and Post process module of thesheet metal forming simulation system. The author also studied some key technology inPro- and Post module of the sheet metal forming simulation system. Some explore aremade in the fields of Graphic Transfer, realistic image of geometric model and dynamicselecting of displayed node and element etc. The light model of the system is finally basedon the widely used Phong light model, which can easily get realistic image of geometricmodel and meet the needs of Graphic display of the system. Based on the study of finite element theory, the author developed the sheet metalforming simulation solution package - FASTAMP, which combines the analysis power ofFASTAMP_Solver with the streamlined Pre- and Post- processor functions ofHUST/FASTAMP. The Pre-processing module of FASTAMP combines high compatibility data transferinterface of IGES & VDAF, efficient surface mesher and powerful geometry reworkfunctions. Post-processing module provides visualization of the computed results and isvery easy to use. FASTAMP_Solver based on inverse approach can perform die design II<WP=6>and formability simulation of sheet forming to give the numerical analysis reference forprocess design, die structure design and optimization of process parameter. It can not onlydevelops accurate blank shapes for improved material utilization, but can predicatesthickness distribution, strain distribution, fracturing area, shrinking area, and so on.更多还原