Interfacial interaction and deformation characteristics of composite beams with interfacial slip considered
Wang Huaping1,2
1. Lanzhou University, Lanzhou 730000, China;
2. Harbin Institute of Technology Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin 150090, China
Abstract：Steel-concrete composite structures are one of the most important structures in modern civil engineering, and the interfacial bonding state is quite significant for maintaining the structural performance of the composite structures. When loads are applied to composite structures, the extensively used flexible shear connectors for transferring the shear force may easily deform, which leads to the occurrence of interfacial slip between the steel beam and the concrete slab, the decrease in the stiffness of the composite beam, and weakening of the safe and stable service performance. Therefore, it is particularly significant to understand the interfacial interaction of the composite beams based on mechanical modelling, explore the occurrence of the slip, and propose targeted optimal design to avoid or postpone the interfacial slip. For this reason, a novel theoretical model for the interfacial interaction and mechanical properties of the steel-concrete composites is established. Based on the theory of elastic mechanics, the interfacial bond-slip model is introduced to consider the influence of slip on the structural performance of the composites, and analytical solutions of the interfacial slip are provided to quantitatively describe the distribution law of slip. By comparing with experimental results, the effectiveness of the analytical formula of interfacial slip and deformation characteristics is validated. Furthermore, sensitivity of the material and geometrical parameters of composite beams to the interfacial slip is investigated. Throughthe theoretical modelling and parametric analysis, priority design parameters of the composite beams are suggested to control the interfacial slip damage and achieve the optimum bearing capacity. Different from the commonly used energy methods, numerical methods and finite element methods, a novel, concise and straightforward analytical solution for describing the interfacial interaction of composite beams in the whole span is proposed for the first time.
