Tensile properties of 3D multi-layer wrapping braided composite: Progressive damage analysis

摘要

An experimental and numerical study on mechanical properties and damage behavior of 3D multi-layer wrapping braided composite under axial tensile load is presented. The braiding process of this material is introduced and its tensile properties are obtained in tensile tests. Numerical simulations employ periodical boundary conditions, with interface elements between yarns and matrix added to improve the accuracy of prediction. 3D Hashin-type criteria and Von-Mises stress criterion are employed as damage initiation criteria for yams and matrix, respectively. The obtained numerical results show a good agreement with the experimental data. The load-bearing capacity and failure mechanisms of 3D multi-layer wrapping braided composites under axial tensile loading are also discussed. A stress distribution shows that the axial yarns are the main load-bearing component of the composite. The main failure mode of the yams is the yam-matrix tensile cracking in the width direction, followed by the yam-matrix tensile cracking in the thickness direction and fibre tensile failure. When the fibres in axial yams begin to break, the material loses its load-bearing capacity.