A multiscale mesh generation method for textile composite

In order to solve the problem of distortion, interference and sharpening caused by irregular cross-sectional yarn shape and material boundaries, a mesh method and unit splitting mechanism for textile composites based on fabric microstructure are proposed. In this method, the point cloud of fabric unit-cell micro-geometry is established by textile modeling software DFMA. Based on the structural point cloud, the yarn path and cross-sectional shape are calculated, implementing the modified Delaunay triangulation Alpha-shape algorithm. The yarn surface mesh is then placed in and match with the voxel mesh. The periodic boundary is introduced by grid mapping. Penetration and narrow gap between yarns are eliminated. Finally, split the voxel units to ensure the continuity of the material. The mesh models of plain weave, three-dimensional integral orthogonal and interlayer orthogonal composites are generated using the proposed method. The damage initiation and evolution criteria of textile composites were established based on the strain-continuous damage criterion and exponential decay model. The mechanical properties of plain weave composites under shear load are simulated. The results show that, compared with tetrahedral and hexahedral meshing methods, the proposed mesh method is capable of more accurately restoring the internal geometry of woven composite materials, dealing with sharp borders and complex surfaces in 2D and 3D fabric structures, and obtaining smooth yarn surfaces and clear cross-sectional shapes. The total number of meshes of the proposed mesh model is moderate, and the calculation time is only 15% of that of the TexGen model. The difference between simulation results and experimental results of shear modulus and strength is 8.93% and 3.73% respectively, which verifies the validity and reliability of the model.