On the thermoelastic response of woven composite materials

The thermoelastic response from a woven composite component is complicated because of the variation in material properties across its surface. In this paper the response is interpreted by treating the woven structure as a 'patchwork' of unidirectional cells and considering each in isolation. To make matters as simple as possible, single-ply specimens loaded in uniaxial tension are studied. The experiments show that, even for this simple tensile case, the strain field is non-uniform and the approach fails to produce any correlation with predictions based on treating each cell in isolation. In deriving the predicted response a detailed knowledge of the material properties required for thermoelastic stress analysis (TSA) is necessary. It is demonstrated that the response is sensitive to small variations in certain quantities and this is discussed in detail in the paper. The TSA is carried out using a new system and a description of this together with the motion compensation techniques used in the analysis of the high-resolution data is provided.