Micromechanical Strength Modeling and Investigation of Stitch Density Effects on 3D Orthogonal Composites

Abstract

A 3D orthogonal woven S2-glass composite is investigated using finite element micromechanics to characterize the stiffness and the strength. The methods are applied to a targeted parametric investigation of the effects of stitch density on strength properties and potential benefits of through-thickness reinforcement, such as resistance to transverse shear and delamination, with some consequent loss of in-plane properties. Direct modeling of the exact microstructure from scanning electron microscope visualization provides a precise knowledge of the mechanics and the failure modes of the microstructure under various loading conditions. Modeling results are verified by comparison to experimental data. In-plane stiffness and strength are predicted with 90% or better accuracy. Transverse shear stiffness was less well predicted, but strength was still predicted within 86% accuracy.

Computation of the effective mechanical properties including nonclassical moduli of 2.5D and 3D interlocks by micromechanical approaches

“…Numerical models include the representative volume element (RVE) [37,38], the repeated unit cell (RUC) [29,39e41], micromechanics strengths model [42] and other models as reviewed in Ref. [43].…”

Numerical identification of classical and nonclassical moduli of 3D woven textiles and analysis of scale effects

“…Numerical models include the representative volume element (RVE) [30,31], the repeated unit cell (RUC) [28,[32][33][34], micromechanics strengths model [35] and other models as reviewed in [36]. These models rely on different simplifications on the fabric architecture and may not be able to accurately describe the local stress distributions at the fiber or yarn scales.…”

Micro/meso-scale damage analysis of three-dimensional orthogonal woven composites based on sub-repeating unit cells

“…The quasi-static mechanical properties of 3DOWCs were investigated mainly by experimental methods, such as tensile strength and failure mechanisms, 17–25 compressive characteristics 26–29 and shear responses. 26,30 For the theoretical analysis, the investigations are usually focused on analyzing a representative volume element (RVE) 31,32 or repeating unit cell (RUC) models, 33–42 micromechanical strength model 43 and much more modeling strategies for other types of 3D woven composites can be referred to the review article by Ansar et al 44 and many references therein. The above-mentioned RVE models including direct numerical simulation (DNS), laminate block, mosaic models and micromechanical strength model have made different degrees of simplification on the complex fabric architecture in the 3DOWC and may not be able to provide accurate details of local stress distributions at fiber or fiber yarn scales.…”