Hygrothermal effects in composites: Influence of geometry and determination of transverse coefficient of thermal expansion

This work evaluates the influence of geometric properties, the length-to-width ratio, named Aspect Ratio, on curvatures in [theta - 90/theta](T) carbon/epoxy composite laminates at room temperature due to thermal residual stresses. A new method to determine experimentally thermal residual curvatures in composites laminates by defining small-length increments on the surface of deformed plate has been exposed. [-45(4)/45(4)](T) was considered to obtain a simple analytical expression of twisting curvature. A new way to determine transverse coefficient of thermal expansion alpha(2) is proposed in squared laminates based on experimental values of twisting curvatures of [-45(4)/45(4)](T) laminates.