三维超塑成形扩散连接过程的接触算法

FEM CONTACTING ALGORITHM OF 3-D SUPERPLASTIC FORMING & DIFFUSION BONDING

对 SPF/DB加工过程中板材的动态扩散连接问题进行了分析 ,该过程属于有限元分析中粘着式接触问题 ,并提出了新的接触判断方法 ,同时采用 Mindlin壳元 ,对非对称双室盒形件的

The dynamic process of SPF/DB is analyzed as an adhesion contact problem in FEM analysis. During the process, contact occurs not only between the tool and the sheet but also between different parts of the sheet. Some approaches for contact search have existed, but most of them are for the contact problem between the tool and the blank. In order to solve the contact problem of different parts of the blank, a new algorithm for contacting judgment is proposed. The basic idea is as follows: after the convergent value of velocity field is acquired, contact search is performed for every node on the slave surface in the possible contacting zone with respect to the elements of master body, and the distance between them is calculated. According to the relation of the distance vector and the vector of contacting element area, and the condition of contact, it can be judged whether or not a node on the slave surface and the corresponding master surface are in the state of SPF/DB. Finally, the Mindin shell element is employed to simulate the SPF/DB process of an asymmetry double cell cup to examine the efficiency of the new algorithm.