Evaluation of stability behavior of the steel truss-arch composite structure

Abstract

Current steel truss-arch composite structure (STACS) is designed referring to design routines of traditional steel arches and trusses. This article studies the stability behavior of the STACS equipped with flexible hangers by numerical simulation, and explores the deformation characteristics and distribution of internal forces of the STACS. The results indicate that the arch of the STACS is dominated by out-of-plane failure under in-plane loading, which differs from the failure modes of traditional fixed steel arches. Additionally, the truss of the STACS experiences a lateral flexural deformation under in-plane loading, which exhibits distinct deformation characteristics compared to typical steel trusses as well; consequently, it may be unsafe to design a STACS according to current design routines. In this investigation, the failure mechanism of the STACS was revealed from the perspectives of internal force, stiffness, and stress. The significance of structural design parameters on the stability of the STACS was evaluated by variance analysis (ANOVA) and joint hypotheses test (F-test). The influences of design parameters on the stability safety of the STACS were clarified through parametric analysis. These findings can determine the design focus of the STACS and provide a basis for establishing design methodologies.