Experimental research of replaceable Q345GJ steel shear links considering cyclic buckling and plastic overstrength. (July 2017) - Liu, Xiao-Gang
Abstract: Coupon tests confirmed that Q345GJ steel had good ductility and rarely cyclic hardening. Therefore, 12 shear links using such steel were designed and tested. The explored parameters included web aspect ratio, flange width-thickness ratio, the equivalent link length coefficient eV p / M p, stiffener spacing and thickness, hysteretic loadcase, and welding details. Discussions and analysis on the failure mode, the hysteretic behavior of shear load and displacement angle, the strain distribution, the bearing capacity and stiffness, the plastic overstrength, the deformation and energy dissipation capacity, were also conducted. The shear links had satisfactory energy dissipation capacity under multiple hysteretic loading with almost no cyclic hardening. Web aspect ratio and stiffener spacing had determinate influence on cyclic web buckling, as well as the ultimate deformation capacity. Yet, more intensive stiffener spacing was prone to result in more serious stress concentration in the web, and caused web fracture. Also, smaller coefficient eV p / M p was harmful to the ultimate deformation capacity. The ultimate plastic overstrength V u / V p of the shear links was about 1.35 to 1.5, influenced by web aspect ratio, the coefficient eV p / M p, and stiffener spacing. To avoid cyclic flange fracture, the coefficient eV p / M p was also suggested be within 1.7. Highlights: The replaceable energy dissipation shear links using Q345GJ steel were proposed and studied. Totally 12 specimens were designed and tested. The cyclic web buckling behavior were investigated with comparison to Popov's proposal. The plastic overstrength behavior with shear displacement angle exceeding 8% was discussed. Suggestions for parameters such as the stiffener spacing, eV p / M p, and web aspect ratio were proposed.