A recurring theme in ANSYS Technical Support queries involves the separation of rigid-body from material deformations without performing an additional analysis. Many users simply assume this capability should exist as a simple post-processing query(or that in any case, this shouldn\u2019t be a difficult operation). \u201cRigid-Body\u201d displacements implies a transient dynamic analysis (as such displacements should not occur in static analyses), but as we\u2019ll see, there are contexts within static structural environments where this concept DOES play an important engineering role. In static structural contexts, such rigid-body motion implies motion transmitted across multiple-bodies. There are two important and loosely related contexts we\u2019ll look at; zero strain rotations of the CG and those rotations combined with strain-based displacement.<\/p>\n\n\n\n
The following presentation explains the issues including the math behind it, offers solutions including useful APDL macros, and then gives examples.<\/p>\n\n\n\n
The models and macros used are in this zip file:<\/p>\n\n\n\n