Thermally-induced shapes of unsymmetric laminates

Models to describe the shapes of unsymmetric laminates produced with a flat mould have been already developed by several researchers. These models are reviewed and on some points theory is extended. The experimental work done so far to confirm the developed theoretical models is rather limited. This especially applies for angle-ply laminates, on which no experimental work has been reported yet. This paper presents new experimental work that has been conducted both on cross-ply and angle-ply laminates over a wide range of laminate dimensions. The experiments show that the influence of the side length on the curvature is very well predicted both for cross-ply and angle-ply laminates, also the bifurcation point behaviour is clearly observed. Possible causes of differences between theory and experiment are outlined. The theoretical predictions are especially sensitive to the transverse thermal expansion coefficient of the individual layers.