Genetic algorithm in structural damage detection

Detection of structural damage is an inverse problem in structural engineer ing. There are three main questions in the damage detection: the existence, location and extent of the damage. In this study, the problem is formulate d as an optimization problem, which is then solved by using genetic algorit hm (GA). Static measurements of displacements at few degrees of freedom (DO Fs) are used to identify the changes of the characteristic properties of st ructural members such as Young's modulus and cross-sectional area, which ar e indicated by the difference of measured and computed responses. In order to avoid structural analyses in fitness evaluation, the displacements at un measured DOFs are also determined by GA. Unlike the traditional mathematica l methods, which guide the direction of hill climbing by the derivatives of objective functions, GA searches the problem domain by the objective funct ion itself at multiple points. The proposed method is able to detect the ap proximate location of the damage, even when practical considerations limit the number of on-site measurements to only a few. (C) 2001 Elsevier Science Ltd. All rights reserved.