Study of the influence of metal structure joining techniques on strength enhancement by means of the finite element method

The most important task designers and draughtsmen are faced with is solving the problem of strength enhancement of joints in various metal structures. Materials of the present article are concerned with accomplishment of the research goal consisting in development of a reliable 3D finite element model designed to study and analyze various joining types used in metal structures and fixed by welding and/or screws. In the course of the goal accomplishment, simulants of butt joints of T-beams were developed by applying the T-flex software. Calculations were performed for double- and single-sided fixing of joinable steel constructions. For double-sided fixing of beams, it turned out that in case of side-joining the model joint and welding the upper and lower plates and in case of joining the model joint by upper seam and welding the side plates, the safety factor was better than that of the welded model only, and the yield strength was lower. When the models are joined one-sided, it turned out that the best results were provided by side-joining the joint with upper and lower plates using screws, with upper and lower plates with screws without welding and with side plates with screws without welding. Moreover, as the number of screws is increased, the safety factor increases and the yield strength decreases when the beam is joined to a vertical plate.