Reply To: Mass Normalized Mode Shape Vector extraction from Ansys Workbench

[dlooman]

Modes must be mass normalized {phi'}[M]{phi} = 1.0 to be used in a mode-superposition analysis and that is default.  Sometimes customers aren't going to be doing a mode-superposition and there's an option to scale the mode so that the maximum dof value is 1.0.  Mass scaled modal displacements can be greater than 1.0  If [M] is very small, {phi} must be large to make {phi'}[M]{phi} = 1.0.  Note also that even with unit scaling, total deformation can be greater than 1.0 because it is the SRSS of three dof, all of which could be 1.0 (probably not though.)