Analysis of thermal stresses in unsymmetric cross-ply composite strips

An approach based on the hypotheses of the classical beam theory for determining thermal stresses in unsymmetric cross-ply strips has been developed. The material behavior is considered linear elastic, and viscoelastic effects are not considered. By supposing linear strain distribution in the cross-sections, the position of the neutral axis, the radius of curvature and the distribution of thermal stresses have been determined. The analysis is valid in the case of large displacements, since the curvature is constant and the deformed shape is an arc of circumference. Five different lay-up configurations of strip geometry specimens have been used for experimental verification. Mid-point deflections have been measured and compared with theoretical values, applying both the proposed approach and the classical laminated plates theory.