Numerical Guided Wave Analysis of an Isotropic Structure with Optical Fiber Bragg Grating Sensors

Abstract

The use of ultrasonic guided waves (GW) in analyzing structural integrity with Fiber Bragg grating (FBG) sensors is a promising topic to implement more in the industrial world. The paper deals with the GW-based analysis of an isotropic aluminium structure using the numerical finite element method (FEM). A set of hybrid FBG and piezoelectric transducers (PZT) are modelled to check the quick SHM GW process in isotropic structures. The PZTs are used to excite the GW that is sensed by the FBG. Multiple damaged sites with different frequencies are simulated by changing the stiffness matrix at the specified group of 3D elements. The signal processing study involves using cosine distance formulation to identify changes in the signal paths of the GW. The paper highlights the automated process of FEM modeling coupled with Matlab scripting to check FBG/PZT numerical setup effectively and to identify the damage regions in the whole structure for further verification. The FEM work is an extension and verification of the previously proposed experimental study.