A Hybrid Particle Swarm Optimization (PSO)-Simplex Algorithm for Damage Identification of Delaminated Beams

Delamination is a type of representative damage in composite structures, severely degrading structural integrity and reliability. The identification of delamination is commonly treated as an issue of nondestructive testing. Differing from existing studies, a hybrid optimization algorithm HOA , combining particle swarm optimization PSO with simplex method SM , is proposed to identify delamination in laminated beams. The objective function of the optimization problem is created using delamination variables optimization parameters together with actually measured modal frequencies. The HOA adopts a hierarchical and cooperative regime of global search and local search to optimize the objective function. The PSO performs global search for objective function space to achieve a preliminary solution specifying a local potential space. Initialized by this preliminary solution, the SM executes local search for the local potential space to explore the optimal solution. The HOA is validated by a series of simulated delamination scenarios, and the results show that it can identify delamination in laminated beamswith decent accuracy, reliability and efficiency. Themethod proposed holds promise for establishing online damage detection system beneficial for health monitoring of laminated composite structures.