关于ansys mechanical总是出现接触、边界条件冲突?
在采用ansys对模型进行静力学分析时,总是会出现未知错误和两个警告,警告分别是“一个或多个MPC接触区域或远程边界条件可能与施加的其他边界条件、接触或对称区起冲突”“两个或更多远程边界条件共享一个公共面、边或定点”。
查看求解方案信息,里面提到的内容是“Overconstraint may occur for Lagrange multiplier or MPC based contact algorithm. The reasons for possible overconstraint are: ”然后紧跟着下一个警告:“Boundary conditions, coupling, and/or constraint equations have been applied on certain contact nodes (for example 204892). ”和“Certain contact elements (for example 934739 & 917158) overlap with other. ”。
还提到:“Multiple constraints have been applied on degree of freedom 3 of contact node 1164102. The program will remove certain internal MPCs. Please check the model carefully. ”
最后:“The dependent term of internal constraint equation 247416 created by contact pair could not be identified. It is likely that either a displacement boundary condition has been applied directly onto a constraint equation or two or more constraint equations share too many degrees of freedom. ”
查找节点ID号后发现有几个是弹簧选择的面上的节点,还有几个居然是纯平面上的节点,我将弹簧抑制后,还是有问题。警告中多次提到“过约束”,我怀疑可能是多孔共用回转约束的问题。我想倾角一下,当五个连杆,从左到右编号分别是1,2,3,4,5,它们一端共用一个销轴,且满足1和5同步运动,2和4同步运动(即认为是一个杆),这种情况下应当如何定义接触?我现在的接触定义是:选择“几何体-几何体”中的“回转”,将1和5的同轴心面作为“参考”,将2和4作为“移动”,然后再插入“几何体-几何体”中的“回转”,还是选择1和5作为“参考”,然后将3作为“移动”。这种分配方法是否有严重后果?理应如何定义三杆同销轴?