Flexible tubular metal-polymer adhesive joints under torsion loading

Bonded tubular joints are currently found in many different engineering applications, ranging from large scale structures to smaller technological subsystems, providing an efficient method for joining dissimilar materials while ensuring excellent sealing capabilities. In the present work, a flexible tubular metal-polymer adhesive joint was studied. This joint is used in the construction of a liquid cooling system, and is designed to withstand large torsional deflections. Three different layouts were considered, in order to assess the influence of the manufacturing procedure on joint performance, especially with regards to the optimal surface treatment and the geometrical parameters of the adhesive layer. The substrate materials were characterized to better understand the joint behaviour and a custom bonding fixture was designed to produce this type of joint. Results show that the layout of the joint, considering its geometry and materials, has a major influence on the mechanical performance of the joint and the torsion test results allowed to identify an effective overlap length, supporting numerically obtained results from a complementary work.