Effect of Residual Thermal Stresses in Curing Process on the Deformation of Flat and Cylindrical Composite Laminates
Unsymmetrical composite laminates deform from the flat state in curing process. According to the "lamination theory" the cured shape of unsymmetrical laminates should always be saddle-like, while considering parameters like specimen lengths and cure temperature, it may lead to two cylindrical shapes. In addition it is necessary to consider geometrical non-linearity for the uneven plates. By considering specimen dimensions, Rayleigh-Ritz energy method precisely predicts the room-temperature shapes of the unsymmetrical polymer composite laminates. In this research, energy equations are developed to determine curvatures of unsymmetrical composite thin laminates at higher scales. Cylindrical cross-ply composite shells are selected to investigate energy method with higher degrees. Cured shape of composite shells is mainly dependent on the stacking sequences, mold radius, layer thickness and cure temperature. Therefore, the changes of these parameters are studied and consequently appropriate assessments are made on the results obtained.
کلیدواژه ها [English]
thermal stresses, polymer composite, unsymetric laminates, deformation, energy methode