Dynamic micromechanical modeling of textile composites with cohesive interface failure

Micromechanical finite element modeling has been employed to investigate the failure of several compositionally varied textile composite materials under dynamic loading. A previously developed cohesive element failure model for interface strength is employed at the phase boundary between the fiber tows and the interstitial matrix to determine the effects of interface properties on the failure behavior of a 2D plain weave and 3D orthogonal weave S2 glass/BMI composite. Thus, tow pullout and separation have been included in addition to more classical micro-level failure modes such as fiber breakage and matrix microcracking. The dynamic response of a representative volume element (RVE) is determined at strain rates of 1000 and 10,000 strain/s in an explicit finite element formulation. A parametric study has investigated compositional effects on impact strengths of two weave geometries with a relatively 'strong' versus 'weak' interface property at 10,000 and 1000 strain/s in tension and compression. The successful implementation of the cohesive failure scheme into the textile RVE framework is shown, and fundamental macro-level failure cases are investigated to relate micromechanical parametric variation to consequent strength effects.