面向产品设计的回弹模拟与几何补偿方法研究

发布时间：2018-04-11 19:50

本文选题：先进高强度钢板 + 全工序精细化仿真　；参考：《华中科技大学》2014年博士论文

【摘要】：随着汽车安全性和轻量化要求的不断提高,高强度钢板和铝镁合金等材料应用的比例越来越高,但给产品设计和模具制造带来了很多新的问题。回弹是高强钢板和铝镁合金板冲压成形的主要缺陷之一,严重影响模具试模周期和零件的尺寸精度,是现阶段汽车冲压成形的研究热点。由于回弹的影响因素较多,目前有限元数值模拟技术还不能准确预测成形后的回弹量,主要依靠现场的反复试模来修正回弹量,严重影响了模具制造周期和质量。因此,急需一种从产品设计、模具设计到模具调试过程的解决方案,能够快速预测和补偿回弹,提高先进高强度钢板冲压件的尺寸精度。论文结合国家科技重大专项：““高档数控机床与基础制造装备”的子课题-高强钢板冷冲压成形技术研究”(项目编号2010ZX04014-072)和国家自然科学基金资助项目：“DP和TRIP钢板冲压成形工艺参数及表面损伤的数值建模与模拟研究”(50905066),对汽车先进高强钢板结构件的回弹工艺控制法的试验、全工序精细化回弹仿真、几何回弹补偿算法及系统、面向产品的快速模拟方法进行了深入的研究。并在此基础上,开发了首个应用于冲压同步工程的面向产品开发全流程的集成系统。为了研究高强钢板回弹的工艺控制规律,采用伺服成形技术研究了工艺参数对先进高强钢板和铝板回弹控制的影响,总结了基于伺服成形的冲压成形回弹工艺控制规律。通过反复加载、增加压边力和镦死力、强压负间隙等方法使板料在厚度方向发生了挤压变形,可以有效减少回弹；而保压时间、成形速度的变化对回弹控制影响不大。试验表明,控制工艺参数只能减少回弹,很难达到消除回弹的目标。因此,为了有效解决回弹,需要进一步借助有限元数值模拟和回弹补偿的方法。数值模拟回弹的精度是目前的主要问题,论文结合S_Rail高强钢板零件强压和负间隙成形试验结果,提出了一种基于厚向多点积分的8节点实体壳单元模型MHSSS,解决了板料受厚向挤压变形的数值模拟问题；进一步建立了基于精细数字化模面为核心的全工序精细化回弹模拟方法。精细数字化模面是以CATIA平台为基础,包括真实的拉深筋模型、真实的强压及空开处理、真实的后工序付型空开处理。通过实体壳单元模型和全工序精细化仿真提高了成形和回弹模拟的精度,解决了先进高强钢冲压成形回弹模拟精度不足的问题。为了解决CAE回弹模拟结果无法直接补偿到精细数字化模面上的难点。对汽车结构零件根据其结构特点和回弹补偿思路进行了精细化的分类研究,提出了一种基于UV线的快速几何回弹补偿算法,并在CATIA平台上开发了一套几何回弹补偿系统。实现了对高强钢板零件回弹的精细数字化几何快速补偿。回弹补偿后的模面能够保持与补偿前模面的拓扑关系和曲面连续性,可以直接用于生产加工制造。在产品设计源头控制回弹缺陷是解决回弹最有效的方法之一,因此面向冲压同步工程提出了基于产品的选择性子结构快速分析和中间工序增量法快速分析方法,实现了对产品的局部区域以及中间工序进行快速的精确模拟。最后以产品为导向,开发了一套面向汽车冲压产品全流程的CAD/CAE/CAM集成系统,为冲压同步工程提供了专用CAE软件支撑。
[Abstract]:With the requirement of vehicle safety and light weight increasing, application of high strength steel and aluminum magnesium alloy material is increasingly high proportion, but to the product design and mold manufacturing has brought many new problems. The springback is one of the main defects of high-strength steel and aluminum magnesium alloy sheet forming, influence precision mold test parts of the cycle and serious, is the current hotspot of automobile stamping. There are many factors to influence the springback, finite element numerical simulation technology can not accurately predict the springback after forming, mainly rely on the scene of the repeated test mode to correct the springback, seriously affect the mold manufacturing cycle and quality. Therefore, in urgent need of a from product design, mold design solutions to mold debugging process, can quickly predict and compensate springback, improve the dimensional accuracy of advanced high strength steel stampings.
According to the national science and technology major projects "high-end CNC machine tools and basic manufacturing equipment" Sub Project - high strength steel plate cold stamping technology research "(Project No. 2010ZX04014-072) and National Natural Science Fund Project:" research and numerical simulation modeling process parameters of DP and TRIP steel stamping and surface damage "(50905066) the test, springback of high strength steel structure of advanced vehicle control method, the whole process of fine springback simulation, geometric springback compensation algorithm and system simulation, rapid method for product are studied. And on this basis, developed the first integrated system for whole process products for stamping simultaneous engineering development.
In order to study the process of springback of high strength steel by servo control law, the effect of processing parameters on the impact of advanced high strength steel sheet and aluminum sheet forming Springback Control Technology, summarizes the Springback Control Law of stamping forming based on servo forming. By cyclic loading, increasing the blank holder force and upsetting force, strong negative clearance and other methods to make sheet metal in thickness the direction of extrusion deformation, can effectively reduce the springback; and the pressure holding time variable forming speed has little effect on Springback Control. The results show that the control parameters can reduce the springback, it is difficult to achieve the goal of eliminating the rebound. Therefore, in order to effectively solve the springback, the need for further compensation by means of the finite element numerical simulation and springback method.
The numerical simulation accuracy of springback is the main problem at present, combined with the S_Rail high strength steel parts forming press and negative clearance test results, this paper presents an integral to the multi point based on thick 8 node solid shell element model MHSSS, solved by numerical simulation to the thick sheet extrusion deformation to further establish the whole process; fine fine spring digital die surface based on digital simulation method. The fine die surface based on CATIA, including the true drawbead model, pressure and air handling real, real pay after the process type processing. Through the air solid shell element model and the whole process of fine simulation improves the forming and accuracy of springback simulation, solved the advanced high strength steel stamping springback simulation accuracy is insufficient.
In order to solve the difficulties of CAE springback simulation results can not be compensated directly to the fine digital die face. For automotive structural parts of the classification of fine according to its structural characteristics and springback compensation method, proposes a fast algorithm based on UV line geometry springback compensation, and developed a set of geometric springback compensation system on CATIA platform. To achieve a rapid compensation of fine digital geometry on high strength steel plate springback. Springback compensation mode and compensation after can keep the topological relationship between the surface and the front mold continuity, can be directly used for the production of manufacturing.
In the design of product source control of springback is one of the most effective rebound, so the stampingsimultaneous engineering puts forward fast analysis method of product selection subsystem of rapid analysis and intermediate process based on incremental method, realizes the accurate simulation on the fast product of the local area and the middle process. Finally, product oriented, development a system for automobile stamping product the whole process of the integrated CAD/CAE/CAM system, provides the special CAE software support for stampingsimultaneous engineering.

【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TB472

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