Simulation-Based Design of a Guided-Wave Structural Health Monitoring System for a Plate-Stiffener Configuration

摘要

Through the use of integrated sensing and signal processing for damage detection, structural health monitoring (SHM) technologies are expected to improve system life cycle management. In particular, guided waves have been successfully utilized for damage identification in pipes and other structures. However, the design of guided wave applications becomes significantly more challenging as the geometric complexity of the structure increases. Structural components for aircraft wings, container tanks, and other applications often have one or more substructures that consist of plates with stiffeners. The application of both higher frequency Rayleigh waves and lower frequency Lamb waves were considered for the inspection of a plate-stiffener configuration for fatigue cracks, with each providing advantages and challenges for practical application. The finite element method was used to better understand both mode conversion and scattering characteristics associated with the crack relative to the rib joint geometry. The multi-objective optimization scheme coupled with a parametric numerical model is lastly discussed for SHM design optimization in terms of maximizing the sensitivity of signal processing measures to crack length while minimizing the significance of secondary signals due to the part geometry and a varying material state.