Anisotropy influence on guided wave scattering for composite structure monitoring

Composite structures are widely used for aerospace applications but prone to barely visible impact damage from low velocity impacts. Guided wave measurements using sparse arrays of distributed sensors provide an important structural health monitoring (SHM) tool detecting and localizing in composites. However, the anisotropy composites needs be considered as it can affect guided propagation scattering, impacting imaging performance. Improved defect characterization achieved by considering scattering characteristics signal processing. Scattering around two different types multiple incident directions a quasi-isotropic carbon fiber reinforced polymer (CFRP) panel were investigated. Full 3D Finite Element (FE) simulations compared measured scattered field at artificial insert delamination. Permanent magnets mounted on undamaged region plate targets both numerical experimental patterns delamination results. Strong directional dependency was observed types, with energy focusing along outer ply layers. For delamination, mostly forward is all directions, whereas magnet blocked transmission directions. 2D matrices calculated, demonstrating distinct behavior each type. Implications angular SHM array discussed.