Prediction for Effective Flange Width of Steel–Concrete Composite Beam with TALHGs

Steel–concrete composite floor framing system with transverse and longitudinal hidden girders (TALHGs) reduces large self-weights and quantities of structural materials compared to conventional composite beams. However, few experimental studies on steel–concrete composite beams with TALHGs are available. Therefore, the prediction of effective flange width and ultimate bearing capacity is still not thoroughly investigated, hindering the understanding and application of these beams. This paper presents a simulation-based method for predicting the effective flange width and the ultimate load capacity of steel–concrete composite beams with TALHGs. Finite element models (FEMs) were developed to analyze how seven key design parameters (e.g., the variation in width-to-span ratio, loading pattern, concrete strength, and the presence or absence of longitudinal hidden girders) affect the effective flange width. In addition, we recommended a reasonable spacing of transverse hidden girders and studied the influence of other structural parameters (the top and bottom thickness of the concrete slab). Based on data fitting and plasticity analysis theory, practical formulas for predicting the effective flange width and ultimate bearing capacity were proposed. The calculated results agreed satisfactorily with the numerical and experimental results, indicating that the suggested formulas are functional for design purposes.