Mechanical modelling of stay-cables under thermal loads

This paper aims at investigating the effects of thermal loads on the elastic response of cables in cable-stayed structures. Starting from a catenary-based approach, an analytical model for evaluating the cable's stress variation induced by a thermal load linearly distributed along the stay chord is proposed, accounting for sag effect as well as for the stiffness of the stay-supported structure. Moreover, the Dischinger's equivalent modulus formulation is generalized to include inelastic thermal contributions, deducing generalized Dischinger-type secant and tangent equivalent elastic moduli, and refining the quasi-secant theory recently proposed. The influence of temperature variations on the mechanical response of typical stays employed in long-span cable-stayed bridges is highlighted through several numerical applications, confirming soundness and effectiveness of the proposed formulation.