Crack identification of functionally graded beam using distributed piezoelectric sensor

Abstract

The present paper addresses development of a procedure for crack detection in functionally graded Timoshenko beam using a distributed piezoelectric sensor. Crack is represented by a pair of translational and rotational springs of stiffness calculated from its depth. A piezoelectric layer bonded to the beam is employed as a distributed sensor. Adopting the double beam model for the beam with the sensor, governing equations are conducted and utilized for establishing a database to propose a procedure for detecting a single crack in a functionally graded beam using the sensor output charge. The modal sensor charge provides a novel indicator more efficient for crack identification in functionally graded beams than natural frequencies. The effect of measurement noise, sensor thickness, and material parameters on crack identification has been investigated for beams with different boundary conditions.