Stiffness study of inner concave cable–arch structure based on an efficient method

Abstract

As a new long-span steel structure, the inner concave cable–arch structure has been applied in several roof structures in China. The mechanical performance of such structure has been intensively analyzed with the widely used finite element method. However, each component of the global stiffness (e.g. bending stiffness) cannot be directly presented in a finite element analysis. For this sake, an efficient method based on the force method is proposed to calculate the global stiffness of such structure. A main advantage of this method is that it can explicitly give the ratio of each type of deformation (e.g. bending deformation) to the total deformation through a simplified analysis. Then, the stiffness analyses of multiple different models are carried out with the proposed method. The results validate that the proposed method is almost as accurate as the finite element method. Finally, to explore the contributions of the arch, the cable member, and the crossing struts to the global stiffness, the relevant analyses of stiffness are investigated in detail for models with different parameters. The results show that (1) the bending deformation dominates the total deformation for an inner concave cable–arch structure, (2) the global stiffness is more dependent on rise-to-span ratio and cross section of the arch than those of the cable, and (3) an inner concave cable–arch structure with crossing multiple struts at a node can present a better mechanical performance than the one with a single strut at a node.