Detection of flaws in composites from scattered elastic-wave field using an improved μGA and a local optimizer

摘要

An effective technique for flaw detection of composites is proposed. In this technique, the detection problem is formulated as an optimization problem minimizing the difference between the measured and calculated surface dis- placement response derived from scattered elastic-wave fields. A combined optimization technique of using an im- proved μGA and a local optimizer is developed to solve the optimization problem so as to obtain the flaw parameters defining flaw configurations. Guidelines for implementing the detection technique, including formulation of the ob- jective function of the optimization problem using different error norms, improvement of μGA convergence perfor- mance, switch from μGA to local optimizer in optimization process, and suppression of the effect of noise on detection results, are addressed in detail. Numerical examples are presented to demonstrate the effectiveness and efficiency of the proposed detection technique.