An experimentally validated damage detection theory in smart structures

A method for the non-destructive detection and location of damage using parameterized partial differential equations and Galerkin approximation techniques is presented. Damages in a structure cause changes in the physical coefficients of mass density, elastic modulus and damping coefficients. This paper examines the use of beam like structures with piezoceramic sensors and actuators to perform identification of those physical parameters, and hence to detect the damage. The method casts the inverse problem as an optimization problem. The iterative method is based on enhanced least-square error minimization. Experimental results are presented from tests on cantilevered aluminum beams damaged at different locations and with damage of different dimensions. It is demonstrated that the method can sense the presence of damage, and locate and characterize the damage to a satisfactory precision. (C) 1996 Academic Press Limited