Experimental and numerical research on overall stability of stainless steel-timber composite beams

Abstract

The overall stability performance of stainless steel-timber composite (SSTC) beams connected by bolts was investigated through both experiment and numerical simulation methods. Two distinct SSTC cross-sectional forms of the SSTC were designed: flange SSTC and web SSTC. Stability experiments were conducted on four SSTC beams. The results indicated that the failure mode of the flange SSTC beam was characterized by flexural and torsional buckling, whereas the web SSTC beam exhibited compressive local buckling. Additionally, the load-displacement curves, mid-span section strain distributions, and the ductility of the SSTC beams were extracted and analyzed. A refined finite element (FE) model was developed to further analyze the SSTC beams, accounting for incorporating the material nonlinearity of both stainless steel and timber, as well as the nonlinear contact interactions among the timber, stainless steel beams, and bolts. The accuracy of this FE model was validated against experimental data. Subsequently, the verified model facilitated a parameter analysis, identifying key factors affecting the SSTC beams, including timber board thickness, width, and bolt diameter. A comprehensive series of FE simulations was conducted, and the resulting data were utilized to calibrate the parameters within the Perry form formula, which is widely employed in the stability design of stainless steel flexural members. This systematic refinement culminated in a specialized formula, precisely calibrated for the overall stability design of SSTC beams.