On the source of the thermoelastic response from orthotropic fibre reinforced composite laminates

Abstract

Abstract In thermoelastic stress analysis (TSA) of orthotropic laminated polymer composites, heat transfer influences the measured stress induced temperature change, or ‘thermoelastic response’. The composite constituents, including different fibre types, fibre geometry, ply thickness and resin systems, in combination with the manufacturing process means that, even for nominally identical materials, different conditions are generated for heat transfer. Hence, definitively identifying the ‘source’ of the thermoelastic response for a general composite laminate has remained elusive. A procedure based on the simultaneous application of digital image correlation (DIC) and TSA is devised that enables the source of the thermoelastic response to be established categorically. In glass fibre laminates, it is shown that heat conduction cannot take place so the thermoelastic response emanates from the surface resin rich layer. In similar carbon fibre laminates, adiabatic conditions are only met at higher frequencies with the response emanating from the orthotropic surface ply.