Behavior of I-section steel beam welding reinforced while under load

• A welding reinforced pattern for steel beams, which has not been tested before, was studied.
• The ultimate capacity of steel beams was significantly enhanced.
• The behavior of beams while being welding-reinforced was investigated in detail.
• FEA considering the welding process can provide a good prediction of the behavior of beams.

An experimental study was conducted to investigate the mechanical behavior of four I-section steel beams, which were reinforced by welding a plate to the bottom and top flange, respectively. For all welding reinforced specimens, the ultimate capacity was obviously enhanced relative to that of the original beams. Preload while the beam is reinforced is proved to be an adverse factor for the capacity if the failure of the beam is controlled by lateral–torsional buckling. During the welding process, larger vertical deflection and web curvature were generated. The torsional section angle decreased if the appropriate welding procedure was adopted. In addition to the experimental study, a type of thermo-mechanical coupling analysis by ANSYS, considering the welding process, was conducted. A generally good agreement between FE analysis and the experiments could be observed from the comparison of the load versus deflection curves obtained from FE and the experiments. It was proved that the FE analysis is reasonable and can allow for the prediction of residual deflection after welding reinforcement. The FE analysis presented in this paper is a reasonable method for simulating the behavior of the steel beams reinforced while under load. With more accurate material parameters and heat source models, the simulation can be further enhanced.