Seismic performance study on Q460 high-strength steel welded cruciform beam-column connections

Abstract

Four Q460 high-strength steel welded cruciform beam-column connection specimens were designed. Among them, different forms of weld access holes were adopted for three specimens, and the locally expanded beam flange configuration was adopted for the other one. Quasi-static tests were carried out on the specimens. Seismic performance of the specimens was studied. The test results show that the specimens have good seismic performance. The ultimate failure modes of each specimen are all shown as the fracture of the beam flange steel base metal or welding material near the weld access hole. Ductility of high-strength steel welded connection can be improved by changing the form of weld access hole. Seismic performance of the expanded beam flange connection specimen was relatively better, which was mainly reflected in the fact that the failure at the weld access hole was delayed in late loading period. Finite element analysis (FEA) was conducted on each specimen. The FEA results were almost consistent with the test results. Analysis shows that the maximum von Mises stresses around the weld access holes of each specimen occurred near the weld access hole toes. The von Mises stress value of each specimen in the middle part of the beam flange width was almost the same. The difference of the von Mises stress values in the beam web height direction of the specimens with different configurations was mainly manifested in the range of three times of the weld access hole height below the upper weld access hole.