Efficient multiscale analysis method for the compressive progressive damage of 3D braided composites based on FFT

A new efficient multiscale simulation method based on fast Fourier transform (FFT) is developed to analyze the nonlinear behaviors of three-dimensional four-directional braided composites under compressive loading which is the key concern for design in the engineering application. The braid yarns within the composites are represented by the microscale unidirectional representative volume element. Both in microscale and mesoscale, FFT method combined with damage theory is used to simulate the progressive damage and failure of the composites under external loadings, in which the interface between the fiber and matrix and fiber compression instability on the microscale and the shear nonlinearity of the braid yarns under compressive loading on the mesoscale are taken into account comprehensively in the computation model. It is verified that the compressive mechanical properties of the braided composites obtained by the efficient multiscale method are in better agreement with the experimental results.