Sequential quantification strategy of delamination in composite laminate via collaborative active and passive monitoring

Abstract

The weak interlaminar strength of composite laminate and rough load environment cause unavoidable invisible delamination and make online delamination identification challenging. In this paper, a sequential quantification method for delamination in thin-walled fiber-reinforced composite laminate by combining active piezoelectric sensors with passive strain sensors is proposed. First, based on the guided wave generated by the alternate active excitation, we accurately estimate the center and boundary points of the delamination sequentially according to the wave propagation characteristics. The reliable boundary characterization of delamination can be achieved. Secondly, we build the mathematical model under the framework of Bayesian posterior inference to match the numerical and the physical damage model. By updating the posterior probability model through the strain measurement, the depth of delamination can be identified finally. Numerical and experimental cases are presented to demonstrate the feasibility, accuracy, and efficiency of the proposed methodology. The robustness is elaborated in detail by the discussion about key parameters and noisy interference.