A boundary element model for piezoelectric dynamic strain sensing of cracked structures

A piezoelectric sensor model is here presented for the Structural Health Monitoring (SHM) of damaged structures. A boundary element approach based on the Dual Reciprocity BEM is then used to model and analyze the transient response of a piezoelectric patch bonded on a cracked beam. The BE model is written for the piezoelectric problem employing generalized displacements. The multidomain boundary element technique is implemented to model non-homogeneous and cracked configuration, taking contact conditions into account. Analyses have been carried out for an isotropic beam with a piezoelectric strip attached on it and dynamical results for the undamaged structure have been compared with FE results showing good agreement. Parametric analysis is performed with the aim to characterize the sensitiveness of the piezoelectric patch by varying the crack positioning along the beam span. More particularly, seven electrodes are considered on the piezoelectric patch and the electrical response of the SHM piezoelectric sensor is characterized by means of a damage index in order to locate the crack.