Multiple damage assessment in composite laminates using a Doppler-effect-based fiber-optic sensor

摘要

In this paper, carbon fiber-reinforced plastic (CFRP) laminates are addressed for the purpose of multiple damage assessment. Doppler-effect-based fiber-optic (FOD) sensors were used to capture guided waves propagating in the CFRP laminates. Characteristics of the fundamental symmetric (S_(0)) and anti-symmetric (A_(0)) Lamb waves in captured guided-wave signals were extracted by taking advantage of linear-phase finite impulse response filter and Hilbert transform, so as to systematically investigate the influence of delaminations on guided-wave propagation. Both dispersive characteristics of multi-mode Lamb waves and features of the Lamb wave-excited fundamental shear horizontal (SH_(0)) guided wave were applied for damage evaluation and multiple damage identification. Results demonstrate that the FOD sensor is effective in multiple damage identification for composite laminates because it is omnidirectional in ultrasonic detection.