摘要
将变形前后各个单元相对厚度变化之和作为目标函数,来衡量成形零件的变形均匀性,以单位长度拉延筋阻力为优化设计变量,采用灵敏度分析的方法,对拉延筋阻力的布置优化进行研究。推导了目标函数对设计变量、节点位移和节点残余力(包括外力)对设计变量、目标函数对节点位移等的灵敏度。将这些灵敏度信息以及反向模拟法计算的应力应变信息,提供给优化算法—非线性规划算法FSQP,通过优化算法,更新设计变量,实现目标函数最小化,直至迭代平衡,输出优化结果。通过NUMISHEET93实例中与增量模拟软件eta/DYNAFORM计算结果的比较,验证了反向模拟法可以快速获取优化的成形工艺参数及优化后的冲压件成形性能。
Since the thickness variation appears to be a good indicator of quality, the objective function is expressed by the thick-ness variation of each element before and after deformation. The intensities of the drawbead restraining forces are supposed to be design variables vector. For sensitivity analysis is implemented to optimize the distribution of drawbead restraining forces, the gradients of the objective function, nodal displacements and nodal residual forces including nodal external forces with respect to the design variables, the gradients of the objective function with respect to the nodal displacement are obtained. These sensitivity information and the resulting strains and stresses distribution by inverse analysis method are given to the nonlinear constrained optimization algorithm FSQP, which updates the design variables in order to minimize the objective function. The optimized results are output until the iterations convergence. NUMISHEET＇93 square box drawing benchmark demonstrates that this strategy can quickly obtain the optimized process parameters. Verifications of the formability with the optimized process parameters have been carried out using incremental theory based software eta/DYNAFORM to show the reliability of the proposed strategy.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2008年第5期155-159,共5页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(10472058)
山东建筑大学博士科研启动基金资助项目
关键词
反向模拟法
灵敏度分析
板料成形
拉延筋设计
inverse analysis method
sensitivity analysis
sheet metal stamping
drawbead design
