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为了预示曲面翻边成形性能,采用有限元仿真、解析计算与人工神经网络的方法对V型零件翻边成形进行了分析.通过建立有限元模型研究了工艺参数对成形性能的影响;基于全量塑性理论及膜应变假定,推导了轴对称情况的解析计算模型;以数值模拟结果作为训练样本,建立了V型翻边成形性能预测的BP神经网络模型.研究结果表明:工艺条件对翻边成形有较大影响,其中以张角的影响最为显著;解析模型计算简便,但是只适用于零件张角较小以及相对翻边高度较小的情况;有限元仿真与人工智能相结合的BP人工神经网络模型可以快速有效地预测翻边成形性. 相似文献
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异形多腔铝型材在绕弯成形区会出现严重的截面畸变,截面两侧形成宽度差,不满足平面度要求.为解决这一问题,本文采用数值模拟和实验的方法,对绕弯成形特性进行研究,并通过优化截面特征减小了成形后两侧面的宽度差.研究表明:仿真能够有效预测实际成形状态,成弧半径值、包角值及回弹角值的仿真与实际误差分别为6.7%,0.5%和11%.成形区仿真与实验所得外弧面宽度分别为79.42及79.00 mm,内弧面宽度分别为82.76及82.90 mm,误差为0.17%.通过优化产品截面得出:增强壁厚的方式不能够抵抗成形过程中立筋向内倒塌的趋势;采取增加微小凸台的方法,使得成形后右侧面宽度差由1.60 mm减小为0.90 mm,左侧面宽度差由1.74 mm减小为0.50 mm,两侧凸台能够有效地抑制立筋向内倒塌.经分析凸台位置最大主应变为0.21,未超过材料延伸率22%,满足强度要求.在8%的增重比约束范围内,优化方案增重1.8%,明显提升了成形工艺性. 相似文献
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目的基于有限元数值模拟软件Dynaform对三通管的成形工艺进行优化。方法分析不同的初始压力、成形压力、轴向进给力、背压平衡力和合模力等对三通管成形的影响。根据成形过程进行模拟,得到分布应力图、厚向应变图、成形极限图等结果,根据模拟结果对零件的成形性进行分析,预测减薄破裂、起皱和回弹等缺陷。结果初始压力在防止侧推头将管坯推皱的前提下,取值应越小越好。成形压力和最大压力能保证减薄率、增厚率和成形度的要求即可。轴向进给对最终的成形质量影响较大。随着摩擦因数的增大,零件的减薄率不断增加,但是增厚率是先减小后增大。结论根据数值模拟的结果能够很好地优化三通管的成形工艺方案。 相似文献
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This article presents the development and application of a coupled finite element simulation and optimization framework that can be used for design and analysis of sheet-forming processes of varying complexity. The entire forming process from blank gripping and deep drawing to tool release and springback is modelled. The dies, holders, punch and workpiece are modelled with friction, temperature, holder force and punch speed controlled in the process simulation. Both single- and multi-stage sheet-forming processes are investigated. Process simulation is coupled with a nonlinear gradient-based optimization approach for optimizing single or multiple design objectives with imposed sheet-forming response constraints. A MATLAB program is developed and used for data-flow management between process simulation and optimization codes. Thinning, springback, damage and forming limit diagram are used to define failure in the forming process design optimization. Design sensitivity analysis and optimization results of the example problems are presented and discussed. 相似文献
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Abel Cherouat Houman Borouchaki Laurence Giraud-Moreau 《International Journal of Material Forming》2010,3(2):1189-1204
In this paper, we are interested in the forming of composite fabric by deep-drawing. Two approaches (geometrical and mechanical) are proposed for the simulation of the composite fabric forming. The geometrical approach is based on a fishnet model. It is well adapted to preliminary design phase and to give a suitable estimate of the resulting flat patterns. The mechanical approach is based on a meso-structural approach. It allows us to take into account the mechanical properties of composite fabric (fibres and resin) and the various dominant modes of deformation of fabrics during the forming process. During simulation of composite fabric forming, where large displacement and relative rotation of fibres are possible, severe mesh distortions occur after a few incremental steps. Hence an automatic mesh generation with remeshing capabilities is essential to carry out the finite element analysis. Some numerical simulations of forming process are proposed and compared with the experimental results in order to demonstrate the efficiency of the proposed approaches. 相似文献