基于精确几何拟协调技术的金属板材大步长隐式成形及回弹算法研究

项目名称： 基于精确几何拟协调技术的金属板材大步长隐式成形及回弹算法研究

项目编号： No.11472071

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 张向奎

作者单位： 大连理工大学

项目金额： 85万元

中文摘要： 全球环境与能源问题的日趋恶化，使汽车的轻量化研究成为当今国际汽车行业和学术界的最热点的研究方向和永恒的研究主题之一。轿车车身重量占整车重量的相当大比重，减小白车身自重是降油耗及减排放的最有效措施之一。当前在车身制造工艺上主要采用高强钢板同时满足轻量化和安全性方面的需求，但高强钢板的回弹问题往往较之普通钢板更为显著，这成为制约高强钢板应用的最主要瓶颈之一。本项目将基于精确几何拟协调技术建立Rotation-Free的高阶NURBS退化壳单元模型，研究NURBS条件下基于物质点映射的中间构型技术，有效解决金属板材冲压成形仿真大步长静力隐式算法中由于刚度矩阵奇异和接触非线性导致的效率、收敛性和求解稳定性等关键问题，在此基础上研究NURBS条件下的回弹预测及补偿算法，为开发具有自主知识产权的高精度金属板材成形和回弹商品化仿真软件包打下良好基础。

中文关键词： 精确几何；拟协调；金属板材成形；回弹；大步长隐式算法

英文摘要： With the deterioration of the global environment and energy problems, lightweight research of vehicles has become one of the hottest research directions and eternal topics of today's international automotive industry and academia. Car Body weight accounts for a large proportion of the vehicle weight, so reducing white body weight is one of the most effective measures to reduce fuel consumption and exhaust gases emission. Currently car body manufacturing mainly applies high-strength steel to simultaneously meet the requirements of cars' lightweight and security design, but the spring-back problem of high-strength steel is often more significant than ordinary steel , which becomes one of the most important constraint bottlenecks in the application of high-strength steel. This project will establish a high-level Rotation-Free NURBS degenerated shell element model based on exact-geometry quasi-conforming technique, and study intermediate configuration technology based on material point mapping under NURBS condition. It could effectively solve these key problems of efficiency, convergence and stability, which are caused by singular stiffness matrix and the contact nonlinear quality in large step static implicit algorithms of sheet metal forming simulation. Based on this study, spring-back prediction and compensation algorithms under NURBS conditions could be further researched, which would lay a good foundation for the development of commercial high precision sheet metal forming and spring-back simulation software with fully independent intellectual property.

英文关键词： NURBS;Quasi-Conforming;Sheet Metal Forming;Springback;Large Time step Implicit Algorithm