Dynamics-based Nondestructive Structural Health Monitoring Techniques

The objective of the proposed research program is to advance the state-of-the-art in structural health monitoring (SHM) through an innovative research program, which effectively addresses the need for an approach capable of detection, diagnosis, and prognosis of damage in aerospace structures. More specific objectives are to use Guided Wave (GW) inspection in conjunction with full-field measurements as the basis for the development of novel analysis tools, which estimate phase gradients of propagating waves for an accurate damage location, predict mode conversion coefficients for damage quantification, evaluate scattering patterns for detailed damage characterization, and allow the determination of Stress Intensity Factors related to different types of damages. The development of the analysis tools will rely on novel and efficient analytical and numerical techniques, including spectral finite element methods and perturbation methods, for the simulation of the interaction of waves propagating in one-dimensional (1D) and two-dimensional (2D) complex structures with various types of defects. Finally the developed concepts and techniques will be transitioned from the laboratory to the field using a novel ultrasonic scanning Laser system, capable of simultaneously recording in-plane and out-of-plane velocity components at extremely high frequencies. BENEFIT: Robust damage detection techniques for deplot level application - detection of fatigue, corrosion, delamination, and disbond type damages - Future developments for onboard sensors for continuous monitoring - Shift of paradigm from scheduled based maintenance to condition based maintenance - Increased flight safety and higher mission readiness - Lower down time for the aircraft