Mechanical Behavior of a Triaxial Woven Fabric Composite

The results of an experimental and finite-element investigation on a single-ply triaxial woven fabric composite loaded in tension are presented. The fabric is made of graphite yarns oriented in the 0 degrees and plus/minus 60 degrees directions and a thermoset resin. It is used by EMS Technologies Canada Ltd. for the manufacturing of super-lightweight spaceborne antenna reflectors. Two types of tensile test specimens were evaluated, straight and dog-bone, as well as three methods for bonding the strain gauges to the specimen. The effects of the specimen shape and bonding methods were evaluated. A finite-element model was developed to predict the behavior of the specimen under tensile conditions. The measured data provide information on the elastic properties and ultimate strength of the composite when subjected to loads acting either along the axial yarns or perpendicular to them.