New Time-Domain Spectral Element And Its Application For Simulations Of Lamb Wave Propagation In Plates With PZTs

As an intelligent detecting method, structural health monitoring has been a hot research focus inindustrial and academic community, since it can evaluate the health condition and improve the safetyof structures in real time as well as make a diagnosis before any destruction and reduce themaintenance. Lamb wave, a kind of stress wave, has many advantages such as long propagationdistance, small attenuation along the propagation path, high sensibility to tiny damages and etc.,therefore, active Lamb wave structural health monitoring method has been widely paid attention byresearchers. However, Lamb wave has several modes and all of them shows dispersion in real projects,so building an effective mechanics model for the research of Lamb wave propagation propertieswould be quite meaningful to the designing of structural health monitoring system. In this paper, anew time domain spectral plate element was developed which can model the three dimensionalbehavior of Lamb wave propagation in two dimensional piezoelectric plates. With the performance oflarger time step and smaller numerical error, the Expanded-Chebyshev nodes were selected to beelement nodes. New displacement and electric potential field functions were proposed and two kindsof effective remedies for thickness locking were discussed. Besides, the secondary piezoelectric effect,time step selection and model reduction were also considered during the solution procedures. Afterthat, FORTRAN programs were written and damage localization in a piezoelectric plate wasinvestigated. Numerical results reveal that the proposed spectral plate element and the correspondingalgorithm raised the accuracy and efficiency of numerical simulation, considerably.