Smoothing interface stress oscillation of composite materials in FFT method by laminate theory

Fast Fourier Transforms (FFT) method can directly use the microstructure images to study the responses of composites, which can avoid meshing geometry and assembling stiffness matrix. To alleviate the local stress oscillation due to the Fourier-type discretization, a restructuring pixels technique based on data compression is proposed. Based on quantitative discussion of the effect of the interface grid layer number, the effective laminate stiffness and strength can be assigned to interface constituted by proper laminates. The proposed method is then developed to analyze the damage and failure of composites, which ensure the correct damage and failure mode prediction.