Delamination detection in buckling laminated composite plates

This paper introduces a new damage detection procedure for laminated composite plates with multiple through-the-width delaminations under compressive loading. The higher-order shear deformation theory is used for the higher-order finite-element formulation. A 13-node triangular element is introduced for finite-element modelling, which includes a parabolic variation of the transverse shear strains through the thickness. As a result, there is no need to use shear correction coefficients in computing the shear stresses. A virtual iso-parametric element is employed to avoid overlapping between delaminated areas. Moreover, w_,n is used as an independent degree of freedom to obtain accurate responses and accelerate the rate of convergence in the finite-element analysis. A two-step genetic algorithm approach for delamination identification is also proposed, which can identify the location and magnitude of delamination in laminated composite plates under compressive loading. By minimising the difference between the analytical responses, resulting from the suggested formulation, and the measured responses, a genetic algorithm identifies the delamination. In this study, some examples are provided to illustrate the accuracy of the formulation.