A combined genetic and eigensensitivity algorithm for the location of damage in structures

Genetic algorithms have been the subject of considerable interest in recent years, since they appear to provide a robust search procedure for solving difficult problems. Due to the way the genetic algorithm explores the region of interest it avoids getting stuck at a particular local minimum and locates the global optimum. The genetic algorithm is slow in execution and is best applied to difficult problems. This paper applies a genetic algorithm to the problem of damage detection using vibration data. The objective is to identify the position of one or more damage sites in a structure, and to estimate the extent of the damage at these sites. The genetic algorithm is used to optimize the discrete damage location variables. For a given damage location site or sites, a Standard eigensensitivity method is used to optimize the damage extent. This two-level approach incorporates the advantages of both the genetic algorithm and the eigensensitivity methods. The method is demonstrated on a simulated beam example and an experimental plate example. (C) 1998 Elsevier Science Ltd, All rights reserved.