基于预偏移的激光拼焊板焊缝优化补偿方法

激光拼焊板成形时,由于两侧母材性能不同会产生焊缝移动现象,造成实际焊缝与设计焊缝位置不符。利用增量有限元解算工具,针对激光拼焊板的拉深成形过程,提出一种基于预偏移的激光拼焊板焊缝补偿方法。建立激光拼焊板成形有限元分析网格模型,通过对比成形前后设计焊缝和实际焊缝之间的差异,推导拼焊板焊缝偏差评价模型。以毛坯焊缝节点的位移预偏移量作为设计变量,以成形后的焊缝位置与设计焊缝位置的偏差最小作为优化目标,建立优化设计的数学模型。利用坯料网格的变形实现焊缝的预偏移,自定义外部优化程序实现预偏移策略。通过有限元迭代求解,补偿拼焊板成形过程中的焊缝移动,使成形后的焊缝位置与设计焊缝位置保持一致,对所提方法的有效性进行实例验证。

Pre-offset-based Approach to Optimizing and Compensating Weld-line of Tailor-welded Blanks

In forming process of tailor welded blanks(TWBs),weld-line movement leads to the inconsistency between the design weld-line and the actual weld-line.Therefore,aimed at the deep drawing process of TWBs,a weld-line compensating approach based on pre-offset is proposed,which employs the incremental finite element method(FEM) solver.A mesh model for FEM analysis is created.By comparing the difference between the designed and the formed weld-line,an estimation method is deducted.An optimization model is established,in which the nodal pre-offsets of the weld-line are selected as design variables and the minimum deviation between the designed and formed weld-lines is selected as the objective function.The weld-line movement during the forming process is compensated through FEM iterative solving,thus reaching a positional agreement between the formed weld-line and the designed one.An example shows the feasibility of the proposed approach.