Reconstruction method of microstructure and mechanical properties simulation of three-dimensional needling composites

The in-situ tensile X-ray micro-CT technology，image analysis and fine structure reconstruction method are used to complete the quantitative description of complex geometric structures such as fiber and crack of three-dimensional needling composites. The reconstruction model of fibre structures such as needling fiber bundle is established. A multi-scale finite element modeling method for three-dimensional needling composites is proposed and applied to the simulation and analysis of tensile mechanical properties. The results show that the three-dimensional needling composites fracture location under tensile loading shows overall fibre fracture，and woven layer bears more tensile load and has a higher number of broken fibers than other layers. The user subroutine UMAT in ABAQUS software and the method of process parametric modelling，representative volume element is used in unit cell analysis to carry out meso-progressive damage analysis，the process parameter transfer between macro and micro scales is achieved and the predicted value of the tensile modulus is greater than the experimental result，with an error of 9.2%. The research method and results of this paper can provide the basis for the parametric modelling of material needling process and the research of process design and mechanical analysis.