Abstract The paper presents the strength evaluation of the beam made of the sheets from the aluminum alloy 6061-T6 and titanium alloy grade 5. The beam was made of two C-profiles connected by the webs, with the flanges reinforced by the flat bars. Channels were made by bending alloy aluminum 6061-T6 sheets with a thickness of 0.8 mm. Flat bars made from titanium alloy grade 5 having a thickness of 0.8 mm were used to reinforce the flanges. The metal sheets components were connected by Refill Friction Stir Spot Welding RFSSW and Resistance Spot Welding RSW technology. The welding parameters of RFSSW and RSW were selected on the basis of the strength of the joints with a single RFSSW and RSW spot. The joints made of two aluminum alloy 6061-T6 sheets, as in the case of the beams webs, and the joints made of aluminum alloy 6061-T6 and titanium alloy grade 5 sheets, as in the case of beams flanges, were analysed. The beam was subjected to three-point bending using the optical deformation system analysis Aramis. The load-capacity of the beam, the distribution of plastic strains on the reference surfaces and the method of beam cracking were analysed. The results of experimental studies were compared with the results of numerical analysis performed using the ADINA System based on the Finite Element Method.