SHM/NDE Research at the Laboratory of Active Materials and Smart Structures

Abstract

AbstractThis paper reviews recent structural health monitoring (SHM) and nondestructive evaluation (NDE) research at the Laboratory for Active Materials and Smart Structures (LAMSS) of the University of South Carolina, USA. A common theme throughout our research efforts is the judicious combination of theoretical exploration, numerical simulation, and experimental measurements. Both passive and active SHM methods have been pursued.The active SHM research has focused on detecting various types of composite damage using guided-wave interrogation and sensing. The composite damage considered covered both seeded delaminations and barely visible impact damage (BVID).The passive SHM research was focused on recording acoustic emission (AE) wave signals created during fatigue loading of aerospace-grade sheet-metal coupons. The AE signals were analyzed for finding specific signatures associated with fatigue crack growth. It was found that not all AE signals were associated with fatigue crack growth, some resulting from the interaction of the faying surfaces.The NDE research was focused on developing novel methods for damage detection with particular focus on composite materials. Remarkable results were obtained in using angle beam transducers (ABT) to selectively excite either quasi-S0 or quasi-SH0 guided waves in composite materials. Eddy current methods were used to detect composites flaws and damage.KeywordsStructural health monitoring (SHM)Nondestructive evaluations (NDE)Acoustic emission (AE)Fatigue crack growthHigh cycle fatigue (HCF) experimentAE signal mode separationPredictive modeling