abaqus建模中,在解析刚体设置参考点后出现了一下的报错,TherigidbodieswiththereferencenodescontainedinnodesetErrNodeRefNodeNoRot1Axishaveatleastoneaxisaboutwhichtherotaryinertiamagnitudeiszero,andtherigidbo

Question

abaqus建模中,在解析刚体设置参考点后出现了一下的报错,
The rigid bodies with the reference nodes contained in node set ErrNodeRefNodeNoRot1Axis have atleast one axis about which the rotary inertia magnitude is zero,and the rigid bodies have atleast one rotational degree of freedom which is unconstrained.Either rotary inertia must be defined at the reference nodes or all of the rotational degrees of freedom at the reference nodes must be constrained.See the status file for further details.

Answer 1

一个刚体,如果在所有自由度上有任一一个自由度方向没有被约束住(或者设置边界条件)的话,那么在收到载荷时,在这个自由度上必然出现无穷大的位移.原因很简单,因为刚体质量为0.即使受到一个很小的力,也会在这个自由度上产生无穷大的加速度.既产生无穷大的位移.
解决的办法是,约束住这个自由度,或者为刚体的参考点设置质量.约束住了自由度,那么刚体就不会"随便"乱跑了.加了质量,那么加速度就不会无穷大.位移也就不会无穷大了.
这个现象不仅仅是刚体,有限元的任意结构都是这样的.