John Doyle
Ansys Employee

There are two sets of terms added for Enhanced Strain when it is invoked for SOLID185 via KEYO(2)=2. – one set addresses shear locking (with 9 internal DOF) and another set addresses volumetric locking (with 4 internal DOF), if mixed u-P formulation is inactive, via KEYO(6)=0.  However, if mixed u-P is activated, via KEYO(6)=1, the volumetric locking terms of Enhanced Strain are not added.   


Simplified Enhanced Strain (KEYO(2)=3) adds the same shear locking terms as Enhanced Strain.  However, Simplified Enhanced Strain never includes terms for volumetric locking, even when mixed u-P is inactive (KEYO(6)=0).

Enhanced Strain and Simplified Enhanced Strain are identical when mixed u-P is invoked, via KEYO(6)=1.