It is often reported that, to successfully join NiTi shape memory alloys, fusion-based processes with reduced thermal affected regions (as in laser welding) are required. This paper describes an experimental study performed on the tungsten inert gas (TIG) welding of 1.5 mm thick plates of Ni-rich NiTi. The functional behavior of the joints was assessed. The superelasticity was analyzed by cycling tests at maximum imposed strains of 4, 8 and 12% and for a total of 600 cycles, without rupture. The superelastic plateau was observed, in the stress-strain curves, 30 MPa below that of the base material. Shape-memory effect was evidenced by bending tests with full recovery of the initial shape of the welded joints. In parallel, uniaxial tensile tests of the joints showed a tensile strength of 700 MPa and an elongation to rupture of 20%. The elongation is the highest reported for fusion-welding of NiTi, including laser welding. These results can be of great interest for the wide-spread inclusion of NiTi in complex shaped components requiring welding, since TIG is not an expensive process and is simple to operate and implement in industrial environments.

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Bonded joints are also widely used to join tubular components in the pipeline industry, in vehicle frames and in space structures. This work performs an experimental and numerical study of axially-loaded tubular joints between aluminium adherends and bonded with three different adhesives. The effect of the overlap length between inner and outer tubes (L O) was addressed in the experiments and numerical study. A Finite Element Method (FEM) analysis was undertaken to analyse peel () and shear stresses () in the adhesive layer. Cohesive zone models (CZM) were employed to predict the joint strength. The CZM technique was positively validated for the strength analysis of tubular joints.