Microscopic structure model and finite element simulation of mechanical properties of fiber-bar composites reinforced by three dimensional weaving

Aiming at the requirement of interlaminar reinforcing of composites, the geometrical structure of fiber-bar composites reinforced by three dimensional weaving was proposed. Three single-cell finite element models based on 0°/90°, 45°/135° and 0°/90°/45°/135° weaving schemes were presented respectively, which can really reflect the mutual squeezing of fiber bundles and fiber-bars in weaving fabrics. Coupled with the periodical displacement boundary condition, the equivalent elastic property parameters of composites based on three different weaving schemes were predicted by the single-cell finite element model. The relationship of elastic properties of composites with weaving scheme and yarn packing factor were studied. The microscopic stress field distributions of single cell based on three different weaving schemes under uniaxial tensile load were analyzed. Several qualified models were made and relevant tests were performed. Results indicate that simulation results obtained by single-cell finite element model make well agreement with the experimental results. The yarn packing factor makes different effect on the elastic constants of the weaving composites. The mechanical properties of composites also vary as the difference of weaving schemes, which mainly result from the arrangement of fiber bundles inside fabrics based on different weaving schemes. The stress field distributions of three weaving single-cell models were exhibited, which provide basis for the fabrics optimization of the fiber-bar composites reinforced by three dimensional weaving.