Tensile Behaviors Of Basalt Fiber Plain Woven/epoxy Resin Composite Under Quasi-static And High Strain Rates

Woven reinforced composite structures will undergo different loading conditions during the service life, for example, the impact loadings. It is highly important to understand their mechanical behaviors for structure design. This thesis reports the tensile behaviors of the single-layer plain woven basalt/epoxy composites under quasi-static and high strain rate loading. The fabric samples were prepared with three different weaving densities, and consolidated with vacuum assisted resin transfer molding (VARTM) technique. The tensile tests were conducted on MTS-810.23for quasi static tensile and the split Hopkinson tension bar (SHTB) system for high strain rate tension tests respectively. From the test results, it was found that the tensile behaviors of the basalt/epoxy plain woven composite materials are strain-rate dependent. The tensile modulus and tensile strength increased monotonously with the increase of the strain rate. The failure strain decreased monotonously with the increase of the strain rate. The resilient energy increased firstly and then decreased with the increase of the strain rate. It was also found that the failure morphologies are also sensitive to the strain rate. In quasi-static tensile tests, the fractorgraph was flat with slight resin fracture, little fiber pull-out and few yarns slip out. While in high strain-rate tensile, the fractorgraph was characterized with complete resin fracture, substantial fiber pull-out, serious slippage between warp and weft. In finite element analysis (FEA), a microstructure geometrical model was established to find the failure mechanisms of the plain woven composites under high strain rate and quasi static tensions. The damage morphologies and failure mechanisms were discussed and verified through comparisons of finite element results and experimental results under different strain rates.The finite element analysis was in general agreement with experimental results. Composite failure mechanisms characterized by initial damage of matrix and followed by breakage of load bearing weft yarns. The results show that mechanical properties are dependent on the weaving density of the fabric.