Theoretical Study on the Influence of Welding Collar on the Shear Behavior of Stud Shear Connectors

Arc stud welding will melt the root of the stud to form a welding collar. For the purpose of exploring the influence of welding collar, numerical method is adopted for the theoretical analysis on shear resistance of the stud under several groups of different welding collar parameters. Firstly, the shear resistance between whether the headed studs considering the welding collars or not is compared. Then, the radius and height parameters of welding collar are changed. Finally, the increment ratio of bearing capacity by welding collars with the same height-diameter ratio is taken into consideration. Experimental data from three push-out test are adopted to validate the accuracy of the numerical method. The results show that the welding collar changes the yield area at the bottom of the stud. The height parameter has less influence than the radius. Under the condition that welding collars have the same height-diameter ratio, the improvement of shear resistance with different diameters roughly converges to 7.28%. The formulas of various countries show that at the height-diameter ratio of 0.25, the average value of bearing capacity of welding collar in various specification approach 7.1% of formula value.