Concrete-filled circular steel tubes subjected to local bearing force: Experiments

Abstract Concrete filled steel tubular (CFST) members are subjected to local bearing forces in a large number of truss and lattice structures. Previous research has focused on rectangular CFST members under such loading condition. There is a lack of understanding on circular CFST members subjected to local bearing force. This paper intends to fill the knowledge gap in this area. A series of tests were conducted on circular CFST, unfilled circular hollow section (CHS) steel tube and plain concrete specimens loaded with local bearing force. The load was applied either perpendicularly to the member or at an angle of 45. A deformation limit was adopted to define the ultimate strength of the specimen since the load verse deformation curve exhibits a ductile behavior. The effects of important parameters were investigated based on the test results. Finally, design formulae were developed to predict the ultimate strength of circular CFST members under local bearing forces.