SOLUTION OF ORTHOTROPIC PLATES BASED ON PARA-EXTENSION OF THE HYBRID-TREFFTZ FINITE-ELEMENT MODEL

The recently presented hybrid-Trefftz (HT) plate elements [J. Jirousek and Lan Guex, Int. J. Numer. Meth. Engng 23, 651-693 (1986); J. Jirousek, Int. J. Numer. Meth. Engng 24, 1367-1393 (1987)] have thus far been limited to isotropic plates. The present paper removes this drawback by extending the library of the optional sets of intraelement displacement functions by a new set of Trefftz functions for orthotropic plates. The new set of trial functions yields as a special case the original isotropic functions, devised so as to preserve the desirable invariant properties of the resulting elements. Numerical examples illustrate the excellent practical efficiency of the formulation and show that the very high accuracy reported for the solution of isotropic plates is preserved for orthotropic plates. © 1989.