基于背景网格技术的冲压成形仿真工具自动装配算法

Automatic Tool Assembly Algorithm of Sheet Metal Forming Based on the Background Mesh Projection

通过对汽车覆盖件冲压成形仿真工具预装配方法的研究,指出建立正确的工具与板料位置自动装配算法需满足三个前提条件:一致的工具(凸模、凹模、压边圈等)法线方向、明确的工具属性和正确的工具整体初始法线方向,并提出一种基于背景网格投影的自动装配算法,即将板料和工具节点沿整体法线方向投影并分配到背景网格,通过工具、板料与背景网格的对应关系,计算出工具节点与板料单元的最小值,从而确定工具需要移动的位置,最终自动完成工具与板料位置关系的正确装配。本算法实现了冲压方向和冲压类型的完全解耦,提高了装配算法的效率和程序的适应能力,简化了用户操作步骤。通过大量复杂汽车覆盖件的实践检验,表明提出的基于背景网格的自动装配算法是行之有效的。

According to the research of tool pre-assembly in automotive body panels forming simulation,three preconditions for effective automatic assembly algorithm are presented：Normal consistent algorithm,definite tool property and correct initial normal direction;the automatic assembly algorithm based on the background mesh projection is also presented.Nodes of sheet and tools are projected and distributed onto background mesh along the overall normal direction,and according to the corresponding relation between tools,sheet and background mesh the minimum values of tool nodes and sheet elements are calculated,thereby determining the distance that tools need to be moved.Ultimately,the correct assembly is accomplished automatically.The algorithm eliminates the coupling relationship between stamping type and stamping direction to improve the adaptability of the program and efficiency of the algorithm,it also simplifies the user operation.The practice in the complex industry model proves the feasibility and efficiency of the new self-assemble algorithm satisfying the requirement of the automotive body panels forming simulation.