警告: FLEX_BODY 1: Attachment node 28330 has zero translational mode shapes for all active modes. The flexible body may behave more rigid than expected if its translational DOFs are constrained. 警告: FLEX_BODY 1: Attachment node 28330 has zero translational mode shapes for all active modes. The flexible body may behave more rigid than expected if its translational DOFs are constrained. 错误: HHT_INT: model could not be assembled when setting up integrator.