Q690 high strength steel T-stub tensile behavior: Experimental research and theoretical analysis

An experimental study on tensile behavior of welded T-stub joint with high strength steel (HSS) under monotonic tensile load was conducted. This experiment program includes twelve welded T-stub joints with different parameters, namely, the bolt diameter, strength grades, bolt distance from the web, bolt edge distance and stiffener. Plastic bearing capacity and initial stiffness of the joints with the different parameters were determined and analyzed, and the results were further validated against the plastic bearing capacity and the initial stiffness formulas in the EC3 Part 1-8. It was found that the plastic bearing capacity and the initial stiffness of welded T-stub joint increases significantly with the increasing bolt diameter, while both of them decreases remarkably as the bolt distance from the web increases. The formulas in EC3 Part 1-8 for plastic bearing capacity and identifying the failure modes are applicable to the welded T-stub joints using HSS. However, the initial stiffness of the joint is overestimated by EC3 Part 1-8. Therefore, a simplified analytical approach considering the bending deformation of bolt is developed, and the average ratio of predicted values to experimental values for the initial stiffness is 1.1.