A QUADRILATERAL PLATE BENDING ELEMENT BY USING AREA COORDINATE METHOD

A quadrilateral plate bending element with 12 degrees of freedom, ACQ, is developed by using the area coordinate method and the generalized conforming approach. The deflection field of the element is expressed with a polynomial of area coordinates which is corresponding to a polynomial of 4th order in Cartesian coordinates (x,y). The twelve generalized compatibility conditions used are 4 point and 4 line compatibility conditions for the deflection w and 4 line compatibility conditions for the normal slope Ψ_n. Since the transform relation between area coordinates and Cartesian coordinates is linear, the formulation of the element stiffness matrix is rather simple. Numerical examples show that the present element has the advantage of high accuracy, good convergence, insensitivity to geometric distorsion and reliability.