QUADRILATERAL THIN PLATE ELEMENTS FORMULATED BY THE AREA COORDINATE METHOD AND THE SHAPE FUNCTION SPECTRUM METHOD

A quadrilateral thin plate element is developed in this paper. There are two distinguishing features in the formulation: 1) The quadrilateral area coordinate method is used instead of the isoparametric coordinate method, so that the element developed is insensitive to mesh distortion. 2) The shape function spectrum method is used to develop the new thin plate element. In other words, the new thin plate element and its shape functions (the higher order shape functions) are developed on the basis of the shape functions of the membrane element (the lower order shape functions). The main features of this method are: The shape function spectrum is composed of shape function of lower power and higher power, and the shape functions of higher power are developed on the basis of the shape functions of lower power. The advantages of this method are: The construction of new element is significantly simplified and the new higher power shape functions are succinct.