Cyclic loading test on welded connection of high strength steel Q460C

In order to study the behavior of the weld of high strength structural steel Q460C under earthquake loading, 11 welded high strength structural steel Q460C specimens were tested by 8 different monotonic and cyclic loading regimes. The corresponding stress-strain relationships under these different loading regimes were analyzed. The constitutive model, mechanical properties, failure modes, deformation, ductility and the cumulative damage deterioration were also studied and compared with the behavior of the base metal. Based on the test results, the cyclic skeleton curves were fitted by the Ramberg-Osgood model. The key parameters in the formula were determined. Furthermore the key parameters of the stress-strain constitutive model of the weld of high strength structural steel Q460C under cyclic loading were calibrated by the test results and accurately simulated using ABAQUS with the mixed cyclic constitutive model. The results show that all specimens of welded connection fracture at the weld heat affected zone, which may be caused by the stress concentration. Welding process results in undesirable influence on ductility of steel structures. Measures should be taken to avoid failure at welded connections.