Optimal Wave Propagation-Based Nondestructive Test Design for Quantitative Damage Characterization

A generalized approach for optimal wave propagation-based nondestructive test (NDT) design for potential applications in damage characterization and other characterization problems, is presented and numerically evaluated. More specifically, the objective of this work is to improve the accuracy and efficiency of material characterization processes by optimizing the parameters of the associated NDT, such as the locations of sensors and actuators. The NDT design approach is an extension of prior work to consider wave propagation-based NDT, and is based on maximizing the sensitivity of the NDT response measurements to changes in the material properties to be determined by the evaluation, while simultaneously minimizing the redundancy of response measurements. Two simulated case studies are presented to evaluate the performance of the optimal wave propagation-based NDT design approach. Both examples consider thin plate structures with a damage field that was assumed to be able to be represented by changes in the Young's modulus distribution throughout the structure. The NDT method considered was based on commonly used ultrasonic testing with piezoelectric sensors and actuators. The Optimal NDT designs corresponding to maximized sensitivity and minimized response redundancy are shown to provide substantially improved evaluation solution efficiency and accuracy for quantitative damage characterization in comparison to more standard NDT designs.