Study on flexural performance of stainless steel-timber composite beams with different combination forms

The combination of steel and timber in different positions is an important design factor for steel and timber composite beams. Stainless steel, characterized by its high strength, ductility, and corrosion resistance, is widely used in construction and civil engineering. To study the flexural performance of stainless steel-timber composite (SSTC) beams with different combination forms of stainless steel bolted connections. Four flange combination and two web combination I-shape section SSTC beams were designed. Four-point bending loading tests were carried out with different flange widths, web heights, and bolt spacings under the two combination forms. Comparative analyses of mechanical characteristics such as damage modes of the specimens, load-deflection curves, combination efficiencies, bending stiffness, and mid-span section strain variation laws were conducted. A finite element model that considered the nonlinearities of stainless steel and timber materials and constructed local geometrical initial defects was established. The findings indicated that the flange SSTC beams demonstrate enhanced ductility and load-carrying capacity when compared to the web SSTC beams, and have better combination effect. The increase in shape section parameters (flange width and web height) effectively increases the flexural stiffness and load carrying capacity of two types of combined beams. The increase in bolt spacing has no significant effect on the load-carrying capacity of the two types of combined beams. An increase in the thickness of timber beams has the effect of enhancing the synergistic ability of combined beams to improve their bending performance. Finally, the bending load capacity calculation method proposed by scholars was evaluated. The calculated values are in good agreement with the experimental and FE values, which can be directly used for calculating bending load capacity of SSTC beams.