【摘要】 模具补偿是金属板料成形中控制回弹的主要方法.针对迭代修正方法在三维模具补偿中效率低、精度差的问题,提出一种基于插值求解与数值模拟的模具补偿方法.通过定义成形后工件形状误差与模具型面偏差之间的函数关系,求解得到了工件成形所需的理想模具补偿量;在有限元模拟中,沿回弹前后节点连线方向进行工件网格面节点反向调整,并对补偿后的节点群进行逆向处理,实现模具补偿面重构.该方法简化了三维模具型面的补偿流程,可实现模具型面内不同位置的独立、非均匀补偿,并保障了模具补偿型面的光顺性.以轨道车辆司机室车顶蒙皮为例,对比了不同模具补偿型面成形后工件的回弹量和形状偏差,并采用研究中获取的理想模具型面进行工件试制,结果表明成形件满足精度要求.更多还原

【Abstract】 Die compensation is the major method to suppress springback for sheet metal forming. Aiming at the limitations of iterative correction method,a die surface compensation method based on interpolation solution and finite element( FE) simulation is proposed. By defining the functional relation between work-piece shape error and die surface deviation,the ideal die compensation quantity is solved in the work-piece forming process. In FE simulation,the grid nodes are reversely adjusted along the node connection direction,and the compensated node group is reversely processed to realize die compensation surface reconstruction. This method simplifies the 3 D die surface compensation process,realizes the independent and inhomogeneous compensation in different positions,and ensures the die smoothness. The roof covering skin of railway train is chosen as the research object,the springback and shape error with different die compensation surfaces are compared. The obtained ideal die surface is utilized to guide the forming experiment,and the result shows that the formed work-piece meets the requirement of precision.更多还原