Fast Fourier transform solver for damage modeling of composite materials

In the case of highly heterogeneous microstructures, such as textile composites herein, conformal FE meshes are difficult to generate for image-based modeling. As an alternative way regular meshing based on the initial image discretization can be used. However, it requires a large number of elements to reduce undesirable effects due to the voxelized discretization of the phase, such as so-called checkerboard pattern. In this work FAST Fourier transform (FFT) based method has been employed by virtue of its simplicity of meshing and efficiency of parallel computation. One of the major contributions is the extension of the FFT method to nonlinear material modeling based on continuous damage mechanics (CDM). Simple test cases are provided to validate the model. In the last part, the FFT with CDM modeling is applied to a real mesostructure of 3D interlock composite from X-ray computed tomography image.