Identification of structural parameters including crack using one dimensional PZT patch model

This article presents a new concept of using the one-dimensional piezo-electric patch on beam model for structural identification (SI). A hybrid element constituted of one-dimensional beam element and a PZT sensor is used with reduced material properties. Accuracy of this element is first verified against a corresponding 3D finite element model. Then SI is carried out as an inverse problem whereby parameters are identified by minimizing the deviation between the predicted and measured voltage response of the patch, when subjected to impulse excitation. A non-classical optimization algorithm Particle Swarm Optimization is used to minimize this objective function. Identified parameters involve stiffness, damping as well as the depth and location of crack in a beam. The validity of the proposed approach is proved by numerical studies on a beam, nine member frame and crack depth and location identification using various patch lengths. The signals are polluted with 5% Gaussian noise to simulate experimental noise. The results show there is a significant improvement in identification accuracy compared to other methods. The proposed method is also successfully verified experimentally.