Elastic Wave-based Damage Detection Using Active Sensor Network

Though serving as competitive candidates to meet §future challenges imposed on aeronautical vehicles, §composite structures run a high risk of losing §efficiency as a result of damage if §without timely detection. Cost-effective and §reliable damage detection techniques are therefore §critical for the confident acceptance of composite §structures. This book presents an elastic wave-based §damage identification technique and an online §structural health diagnosis system for in-service §composite structures, based on investigation of §propagation characteristics of guided elastic waves §in beams and plates bearing damage, in particular §Lamb waves in composite laminates with through-hole §or delamination. Fundamental and mechanism §studies encompass theoretical analysis, finite §element simulation and experimental verification. §Following a review of the state of the art in this §field, the book introduces a signal processing §technique, termed Digital Damage Fingerprints (DDF); §an inverse identification algorithm using a §feedforward artificial neural network (ANN); and an §active sensor network technique based on a novel §concept, Standard Sensor Unit (SSU).