基于拓扑优化的锻造预成形设计研究

Research on forging preform design based on topology optimization

开展了基于拓扑优化的预成形设计方法研究,以坯料完全充满型腔和锻件整体变形均匀为优化目标,提出了一种基于充填性、变形均匀性以及形状控制的多目标增删准则。详细给出了基于拓扑优化的预成形设计实现步骤和算法,包括单元场量追踪和传递、单元增删过程、单元增删数目的确定以及边界节点的拟合。基于拓扑优化算法,结合Deform-2D有限元模拟软件,开发了预成形优化设计程序。利用预成形拓扑优化程序对H形锻件预成形形状进行了优化设计。采用优化后的预成形方法进行终锻成形。结果表明,材料能完全充满型腔,飞边较小,没有折叠缺陷,应变均匀性得到了改善,最大成形载荷大大降低。优化后的预成形形状与终锻件的外形相似,形状复杂度适中,验证了算法的可靠性。

The preform design method based on topology optimization was studied.Taking the complete cavity filling of blank and overall deformation uniformity of forging as the optimization objectives,a multi-objective addition and deletion criterion based on filling property,deformation uniformity and shape control was proposed.The implementation steps and algorithms of preform design based on topology optimization were given in detail,including element field tracking and transmission,element addition and deletion process,determination of element addition and deletion number and fitting of boundary nodes.Based on the topology optimization algorithm and Deform-2D finite element simulation software,the preform optimization design program was developed.The preform shape of H-shaped forging was optimized using preform topology optimization program.Final forging was carried out using the optimized preform method.The results show that the material can completely fill the cavity and the flash is small without folding defects,the strain uniformity is improved,and the maximum forming load is greatly reduced.The optimized preform shape is similar to that of the final forging,and the shape complexity is moderate,which verifies the reliability of the algorithm.