Fatigue performance of the slit end area of slotted CHS tube-to-gusset plate connection

Abstract

Slotted circular hollow section (CHS) tube-to-gusset plate connections are frequently used in structures such as bridges, towers, etc., However the fatigue strength of this type of connections needs to be characterized. In the present study, the fatigue performance of the slit end area of this connection is investigated. Four sets of large-scale fatigue tests on the connection with coped hole at the slit end are carried out. Additionally, fatigue tests on CHS connections, available in the literature, are re-analyzed by means of effective notch stress (ENS) approach. Subsequently, parametric studies are carried out to analyze the influence of different geometrical and welding strategies on the notch stress concentration factor. The shortcomings of the ENS approach applied to this type connection are pointed out, proposing possible alternative solutions. Lastly, the optimal design for improving the fatigue strength of this slotted CHS tube-to-gusset plate connection is recommended.