LISA Modeling of CLoVER-generated Guided Waves and Their Interaction with Damage in Composite Structures

Guided wave (GW) based structural health monitoring (SHM) requires effective transducers to generate and sense the GWs and a comprehensive understanding of the GW propagation characteristics in practical structures. This paper presents the Composite Long-range Variable-direction Emitting Radar (CLoVER) transducer for efficient damage interrogation in GW SHM systems. Its wedge-shaped anisotropic piezocomposite sectors can be individually excited to interrogate the structure in a particular direction, focusing the energy efficiently. As a sensor, the CLoVER sectors spatially filters incoming signals, reducing coherent noise and improving signal-to-noise ratio. The Local Interaction Simulation Approach (LISA) is introduced in this paper as the numerical method to analyze the GW generation, propagation, and damage interaction in composite structures. Experimental results based on CLoVER transducers generating GWs in composite laminates and their propagation characteristics are used to validate LISA simulations. This paper also presents the CLoVER transducer used as a sensor for damage interaction studies and the results are compared with the LISA simulations. The experimental tests with laser vibrometer measurements allow the spatial and temporal evolution of the solution to be evaluated and compared against LISA simulations. The studies show that the wave form, radial attenuation, and azimuthal distribution are well captured by the numerical simulation.