Dynamic analysis of frames by a two-level finite element method

Abstract

A two-level finite element technique of constructing a frame super-element is introduced to reduce the computational efforts for solving large scale frame problems. The ordinary finite element method is used first to yield matrices for the beam members. Then the nodal displacements of all the nodes are related to those of a small number of selected joints (master nodes) in the frame by means of global finite element interpolating functions. Thus the order of the overall matrices is greatly reduced and the frame may be considered as a super-element to be connected to other elements by means of the master nodes. The accuracy of solution may be improved either with finer subdivision or by taking more master nodes inside each super-element.