BOUNDARY ELEMENT ANALYSIS OF THIN-WALLED STRUCTURES USING AN EXPANDING ELEMENT INTERPOLATION METHOD

Abstract

Boundary element analysis of thin-walled structures using a new expanding element interpolation method is presented. The element is obtained by adding virtual nodes based on a traditional discontinuous element. Coupled with the virtual nodes, the shape functions become higher order shape functions and are named fine shape functions. The original shape function of the discontinuous element is named raw shape function. With the expanding element, the interpolation accuracy can be increased by at least two orders compared with the original discontinuous element. The elements are able to naturally and accurately interpolate both continuous and discontinuous fields. The virtual nodes can be obtained by those of adjacent source points using the raw shape functions. Furthermore, the boundary integral equations are built up only at the inner nodes. Thus the size of the equations has not changed. Numerical examples are presented to verify our methods. Results demonstrate the accuracy and efficiency of the proposed method.