Damage Characterization and Remaining Life Assessment of Structural Components with Nonlinear Vibro-Acoustic Technique

Intelligent Sensing Technologies, LLC (IST) received a Phase I SBIR contract to determine feasibility to accurately measure controlled damage accumulation in the samples using nonlinear acoustic techniques and establish the correlation between the parameters of nonlinear response and damage accumulation in various airframe materials. This objective has been met and it has been shown that VMT is capable of detecting and monitoring fatigue damage at an early stage. The primary goal of the Phase II efforts is to develop a damage evaluation model that will establish relationships between the level of modulation and the microcrack parameters (density, size, internal stress). We will demonstrate the accuracy of the models to predict the useful remaining life of the materials. We are planning to achieve this goal through development of phenomenological continuum damage model and experimental validation of the model and measuring technique using statistical and micrographical analysis. In addition, we will explore new measuring methodologies based on physics of sonic/vibration interaction with damaged material utilizing different types and modes of ultrasound and vibration. The proposed efforts will lead to development and demonstration of a prototype system incorporating measuring technique and algorithms for damage detection, characterization, and prediction.