Caratterizzazione di provini tubolari incollati: regolarizzazione della tensione normale mediante gole schermo

This paper experimentally investigates bonded tubular specimens, which exhibit uniform stress distribution within the adhesive layer. The mechanical properties of a thin adhesive layer, subject to a singularity-free stress distribution, are immediately applicable to the description of real joint behavior. The proposed specimen consists of a tubular butt joint, with circumferentially machined stress-relief grooves adjacent to the adherend-adhesive interface. The groove geometry, simplified with respect to a previous numerical work from the author, allows significant reduction in edge effects - as confirmed by finite element analyses. The experimental campaign involves three variables: presence of the grooves, adherend material and adhesive thickness. The presence of stress-relief grooves gives higher failure loads for steel adherends, whilst aluminum adherends show strength reduction as adhesive thickness increases.