A Stabilized MITC finite element for accurate wave response in Reissner-Mindlin plates

Lonny L. Thompson and Sri Ramkumar Thangavelu

Advanced Computational Mechanics Research Laboratory
Department of Mechanical Engineering and Engineering Mechanics
Clemson University
Clemson, South Carolina 29634-0921

Proceedings, Published by Elsevier Science Ltd. Paper MIT41.

First MIT Conference on Computational Fluid and Solid Mechanics, 12-15, June 2001, Cambridge, MA.

Abstract

Residual based finite element methods are developed for accurate time-harmonic wave response of the Reissner-Mindlin plate model. The methods are obtained by appending a generalized least-squares term to the mixed variational form for the finite element approximation. Through judicious selection of the design parameters inherent in the least-squares modification, this formulation provides a consistent and general framework for enhancing the wave accuracy of mixed plate elements. In this paper, the mixed interpolation technique of the well-established MITC4 element is used to develop a new mixed least-squares (MLS4) 4-node quadrilateral plate element with improved wave accuracy. Complex wave number dispersion analysis is used to design optimal mesh parameters, which for a given wave angle, match both propagating and evanescent analytical wave numbers for Reissner-Mindlin plates. Numerical results demonstrates the significantly improved accuracy of the new MLS4 plate element compared to the underlying MITC4 element.