ITERATIVE MATRIX APPROXIMATION FOR MODEL UPDATING

Alternating projection algorithms for matrix approximation are applied for structural model updating. Desired matrix properties such as spar sity, definiteness, and satisfaction of eigenconstraints are imposed a s side constraints for a minimisation problem formulated to produce an updated matrix model which better matches measured data. Included are formulations of the update problem and discussion of the determinatio n of solutions, convergence of the alternating projections approach as seen through geometric interpretations, and experimental verification . These approaches are verified through an application to locate damag e in a laboratory truss structure using stiffness matrix approximation with experimental vibration measurements. (C) 1998 Academic Press Lim ited.