08.40: Numerical investigation of mechanical properties of multi‐planar concrete‐filled steel tubular joints

Abstract

ABSTRACTWith the development of large span and heavy load modern engineering, concrete‐filled steel tubular structures appear constantly. The joints of these structures are mostly multi‐planar joints. In order to solve the problem of lacking of the investigation of multi‐planar concrete‐filled steel tubular (CFST) joints, the mechanical behaviour of CFST KK joints were studied through refined finite element simulation. Accurate finite element models of CFST KK joints were established by considering the material nonlinearity, the geometry nonlinearity, and the contact nonlinearity between the tube and the concrete. The spatial effect of multi‐planar joints was be obtained by comparing with planar joints. The FEA results showed that, the multi‐planar carry‐over effects had the maximum effect for the 60° CFST joints, the strength of multi‐planar joints decreased compared with the planar joints, and the stiffness of them did not vary substantially. While for the 90° CFST joints, both the strength and stiffness of multi‐planar joints did not vary substantially with the planar joints. This research can provide scientific basis for the design of multi‐planar CFST joints, and effectively promote the application of CFST structures.