Impact Tensile Properties And Finite Element Analysis Of3-D Angle-interlock Carbon Woven Fabric

Three-dimensional angle-interlock woven fabrics (3DAWF) are widely used in impact loading application such as personnel ballistic armor, structural and aerospace system, because of its structure which consists of multiple layers of yarns. Compared to laminates,3DAWF has superior strength-to-weight ratio and high tolerance to impact damage. However, these materials can exhibit different mechanical properties when subjected to loading at different strain rates.This paper presents the investigation of the tensile tests on3DAWF under quasi-static and high speed loading. The tensile property and strain rate effect of3DAWF were obtained under different strain rates and when compared, it showed different failure mechanism. A finite element model on the yam level was established to predict the failure mechanism of the3DAWF under high strain rates.The main research was conducted as follows:(1) Sample preparation:Preparing for quasi-static test samples and impact test samples respectively.(2) The tensile behaviors of3DAWF were explored via quasi-static (1×10-3s-1) tests using a MTS810Material Test System. The stress-strain response and fracture morphology at low strain rates were obtained under quasi-static loading.(3) A series of impact tensile tests under different high strain rates were conducted using a self-designed split Hopkinson tension bar (SHTB) apparatus. The stress-strain responses and fracture morphologies were obtained when subjected to loading at different high strain rates.(4) The FEM analysis was based on micro-structure at yarn level to calculate the tensile property which could reveal the failure mechanism under different high strain rates.From the research, the differences in the stress-strain curves under different strain rates confirmed that the3DAWF was highly sensitive to strain rate. This was because3DAWF consisted of multiple layers of yams and when subjected to loading at different strain rates, the interaction between warps and wefts were different.3DAWF showed different mechanical properties under different strain rates because the yarns were breaking at different time interval.