Multiscale failure analysis of 3d braided composite structure by coupling FEM and FFT method

The progressive damage behavior of three dimensional (3D) braided composite beam is studied by using a more efficient multiscale coupling method including fast Fourier transformation (FFT)-based method and finite element (FE) method. FFT-based method with variational principle is used to overcome the poor convergence for composites with large jumps of material properties in mesoscale. The mechanical response of the braided composites is studied using finite element (FE) method in the macro-scale. The predicted strength and dominated failure modes of the braided composites structure obtained by the proposed method are in good agreement with the experimental results. The high computation efficiency is attractive for large structure with the nonlinear mechanical behavior.