Influence of shear connection degree on the bending load capacity of cold-formed U-shaped composite girders

LIN Yanjun; ZHANG Zejun; ZHANG Tiantao

doi:10.3969/j.issn.1672-0032.2025.01.005

Abstract：To study the effect of shear connection degree on the bending capacity of U-shaped composite beams,eight groups of numerical model experiments are designed based on factors such as shear connection degree,number of shear studs,and spacing of shear studs.A validated finite element model is used to calculate and analyze the strain and deflection.According to different codes from China,Europe,and the United States,the minimum number of shear studs required under fully shear-connected conditions is calculated separately.The results indicate that the numerical finite element model can effectively simulate the stress and deformation of the steel main beam and concrete deck slab throughout the loading process of the U-shaped composite beam,with the error between the measured results and numerical simulation results being less than 15％.When the shear connection degree coefficient is between 0.02 and 0.30,the bending capacity of the U-shaped composite beam with a span of 16m continuously increases as the shear connection degree coefficient increases.When the coefficient reaches 0.30,the steel reinforcement and concrete have achieved full shear connection;beyond a coefficient of 0.30,the bending capacity of the U-shaped composite beam shows little variation.The variation of the bending capacity in the elastic stage is relatively less affected by the shear connection degree;partial shear connection is feasible in engineering applications.In the plastic stage,the bending capacity is significantly influenced by the shear connection degree,and the calculation and verification of the bending capacity of the U-shaped composite beam should account for the effect of shear connection degree.The minimum number of shear studs required under fully shear-connected conditions calculated by different codes is relatively close.