Abstract
The paper presents an analysis of tensile tests for welded specimens made of 6061-T6 aluminium alloy. Three kinds of lap joins were made by Refill Friction Spot Stir Welding (RFSSW). The each specimen has one joint, but they were varied in the position of the sheets. In the first, the angle between sheets axes was 0º, to determine the tensile capacity of the joint. In the second and third, the angle between sheets axes was 20º, and -20º. That position of sheets allow determine the maximum load and displacement of stretched and twisted structure. The numerical calculations were performed using the ADINA System based on the Finite Element Method (FEM). The sheets and joints were modelled with 3D-solid elements. The experimental investigations were carried out using a testing machine and a non-contact and material independent measuring system providing, for loaded test objects, accurate 3D displacements and surface strain values. The stress, strain distribution and displacements were analysed. The numerical and experimental results were compared. The structures were assessed in respect of strength and the possibility of applying in the aircraft industry.