Analysis of mechanical performance of modular steel-concrete composite joints considering floor slab composite effects

Abstract

This study establishes and verifies the finite element models (FEM) of MSCCJs to analyze the mechanical performance of modular steel–concrete composite joints (MSCCJs) under monotonic static load without considering the floor slab composite effect (FSCE). Subsequently, 12 MSCCJ models incorporating the FSCE are constructed using ABAQUS. The study evaluates the effects of varying column axial compression ratios (n = 0.15, 0.25, 0.4, 0.6), floor width (w = 800, 1200 mm), floor thickness (t = 90, 110, 120 mm), and floor reinforcement ratio (r = 6 %, 8 %, 12 %) on the bending moment, initial stiffness (k0), ductility, and stress transfer of the joints. The results indicated that as n increases, the shear stress concentration in the joint core module (JCM) and the steel framework at the lower column end become more pronounced. Concurrently, the bearing moment and k0 of the joint also increase. However, once n surpasses 0.4, the joint's plastic properties diminish upon damage. With an increment in w, the k0 and ductility deformation of the joint remain stable and then decline. At w = 1000 mm, the joint's bearing capacity, stress distribution, and deformation performance reach their optimum. Since it significantly impacts stress distribution, its effect on the joint's mechanical performance is minimal. Lastly, the value of r enhances the ductility of MSCCJs and the stress concentration in the reinforcement. It is advisable to maintain r between 1.1 % and 1.7 %.

Keywords

• Prefabricated
• Steel-concrete composite joints
• Floor slab combination effect
• Mechanical performance