AN EIGEN-FORCE METHOD FOR FINITE ELEMENT ANALYSIS AND REANALYSIS

This paper presents a force-based Þnite element method that involves eigen-space transformation of element sti¤ness matrices in the Þrst analysis. In each subsequent analysis (ÔreanalysisÕ) associated with structural variations, the solution obtained previously is modiÞed making use of intrinsic properties of eigen solutions and avoiding the time-consuming task of solving a large system of equations. The structural variations may involve changes in material properties, birth or death of elements, or change in boundary conditions. Numerical examples are presented to compare the accuracy and computational e¦ciency of the proposed method with the displacement-based Þnite element method