Investigations of in-plane shear properties of ±45°-carbon/epoxy composites using tensile testing and optical deformation analysis

Shear properties of carbon/epoxy composites with 0°/90° textile reinforcement structures and different layer thickness have been examined under ±45° tensile loading. Deformation process on specimen surfaces during loading was studied using an optical whole-field measuring method. The results show that the shear behaviour is affected by the layer thickness and/or by the weight per unit area of the reinforcement. The optical deformation analysis of the sample’s surfaces did not show an equal strain distribution, as expected. Moreover, large deviations from the calculated average strain values are obtained. As consequence, the dimensioning of construction units might be influenced by this fact.