Dynamic micromechanical modeling for investigation of interface and tow property effects on strength of 2D and 3D woven composites
Conference
Karkkainen, RL, Yen, CF, Boesl, B. (2011). Dynamic micromechanical modeling for investigation of interface and tow property effects on strength of 2D and 3D woven composites
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Karkkainen, RL, Yen, CF, Boesl, B. (2011). Dynamic micromechanical modeling for investigation of interface and tow property effects on strength of 2D and 3D woven composites
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Dynamic micromechanical modeling has been employed to investigate the relationship between several compositional properties and consequent effects on macroscale impact performance. A previously developed model for interface strength is employed at the tow-interstitial matrix boundaries to determine the effects of interface properties on the failure and failure modes of a 2D plain weave and 3D orthogonal weave S2 glass / BMI composite. Strain rate effects and fracture mode effects are implemented to modify the allowable strain to failure at the interface. Establishing the effect of weave of microgeometry and compositional parameters on consequent mechanical response enables a roadmap for a materials-by-design approach to material development. 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. Interface failure, matrix microcracking, and inter-tow fiber failure modes are incorporated in the total micromechanical failure model. Dynamic behavior and failure modes such as impedance mismatch effects of stress wave propagation and interface failure leading to crack propagation and tow pullout are observed. Macro-level failure envelopes are developed which relate micromechanical parametric variation to strength effects in failure spaces involving axial normal waves as well as dynamic transverse shear loading. Varying effects on failure strain are observed for each parametric combination of: 3D orthogonal vs. 2D plain weave architecture, 10k strain/s vs. 1k strain/s impact loading rate, a relatively "strong" vs. "weak" interface property, and tension vs. compression.
