Research On Multi-scale Modeling And Analysis Of Damage And Energy Absorption Of Woven Composite Structures

Woven composite materials are generally composed of two materials with different mechanical properties,such as fiber bundles and matrix.High toughness,low density and good integrity make them widely used in lower temperature components of aircraft engines.High-speed impact damage caused by foreign objects has become a major concern in the application of woven composites.Therefore,in this paper,through the combination of experiments and multi-scale simulation modeling,the energy absorbing behavior of woven composite materials and its influencing factors were studied.Firstly,the 1000D629T/EPMOLD110 domestic aramid woven composite material prepared by vacuum assisted resin infusion(VARI)was taken as the research object.Starting from the constituent and microstructure of the woven composite material,based on the mean field homogeneity model,the meso representative volume element(RVE)was established.Through quasi-static tensile tests,shear tests and in-plane compression tests,the basic mechanical properties of the material were obtained.A progressive damage model including an exponential evolution law was assigned to the RVE,and the constitutive relationship of the meso-structure model was verified by comparison with the tests.Secondly,the ballistic impact tests of the aramid woven composite plates were carried out,and its damage behavior was investigated by experiments,including the residual velocity,energy absorbing characteristic,failure morphology and other related parameters.The influences of the thickness of the target plate,the preparation technology and hybrid aramid/carbon fabric lay-up materials on the damage and energy absorption of woven composites were further explored.Studies have shown that an increase in the thickness of the target plate can significantly increase the ballistic limit and critical energy absorption,but it will reduce the critical energy absorption efficiency;the improvement of the preparation technology can improve the overall impact resistance of the material;the influence of the hybrid material lay-up on the energy absorbing characteristics will vary with the number and location of carbon fabrics in the lay-up,and needs further study.Considering the mechanical response in the fiber direction and shear response of the woven composite materials,combined with the inter-lamina failure model,the macroscopic material constitutive input parameters were fitted and calibrated based on the meso-model,thereby establishing the woven composite multiscale finite element model under high-speed impact.Compared with experiments,the finite element model can capture the damage and energy-absorbing behavior of woven composites.Based on the established finite element model,the effects of hybrid material lay-up sequence and hybrid ply orientation on material energy absorption were further identified.Studies found that replacing the 2/3 of the aramid composite material in the middle of the target plate with the carbon fiber composite material can effectively improve its ballistic limit and energy absorption capacity;changing [0/90]3s lay-up to [0/90/45/-45/45/-45]s lay-up is a simple method that can effectively improve the energy absorption efficiency of the target plate without increasing the material thickness,hybrid different materials or improving the preparation technology,which provides a reference for engineering applications.