Experimental Confirmation of the Theory of Elastic Moduli of Fabric Composites

Abstract

Some experiments for measuring the elastic moduli of fabric composites are con ducted in order to evaluate the theoretical predictions developed by the authors in their previous work. Experimental results coincide very well with the theory for 8 harness satin carbon/epoxy systems. There exists some discrepancy between theories for con strained and unconstrained local warping in the case of plain weave composites. Ex perimental results are bounded by these two theories. The dependency of elastic moduli on laminate ply number is discovered in plain weave composites. The ratio of ply thickness to thread width is also a very important parameter, which strongly affects the elastic moduli of plain weave composites. The in-plane shear modulus of fabric composites is mainly influenced by fiber volume fraction, which varies linearly with ng. Off-axis properties of fabric composites are measured and compared with theories. The experimental results essentially confirm the validity of the author's theoretical predictions.