This study investigates the mechanical behavior of mooring lines in floating offshore units subjected to thermal variations along the water column, employing a static numerical model based on a heterogeneous extensible catenary formulation. The growing global energy demand and the expansion of deepwater operations have increased the importance of mooring systems for platform stability and station-keeping. As key structural elements, mooring lines provide essential horizontal stiffness, govern restoring forces, and ensure structural integrity. However, conventional design models frequently neglect thermal effects, particularly the influence of depth-dependent temperature variations on deformed configuration of the line and its overall performance. To address this limitation, the proposed model incorporates both multimaterial line segments and vertical oceanic temperature profiles to evaluate their combined impact on horizontal stiffness and restoring capability. Results demonstrate that these thermal variations substantially alter the mechanical response of the line, directly affecting its interaction with the platform. This methodology enhances the reliability of mooring system design and contributes to a better understanding of thermo-mechanical behavior of mooring lines in offshore engineering.
