A numerical study of the effect of penalty parameters for membrane elements with independent rotation fields and penalized equilibrium
We offer a numerical investigation into the effect of penalty parameters in elements with drilling degrees of freedom and penalized equilibrium, for which the stress tensor ? ? is not a priori assumed to be symmetric. The parameters under investigation are ? ? , which relates the in-plane translations to the rotations, and ? ? , which results due to enforcement of stress equilibrium in assumed stress implementations of elements with drill rotations. Rather than simply reporting on the quantitative influence of the penalty parameter ? ? on measures like displacement, rotation and stress, we directly assess the skewness of the nonsymmetric stress tensor ? ? . Results are presented for both isotropic and orthotropic constitutive relationships.
penalty parameter drilling degrees of freedom stress equilibrium