Study on the deflection of butterfly-shaped clips truss girders

With regard to the semi-rigid connection between the clips and upper or lower chord tube, the design of the light-gauge-steel truss girders with butterfly-shaped clips is often controlled by the mid-span deflection. This paper focused on the calculation of the deflection at the mid-span based on experimental research. The method of calculating the mid-span deflection of concrete-steel composite beam was used in this study. Also, in order to consider the slip effect between the upper and lower chord tubes of the girders, the paper took one infinitesimal section of truss girder as a basic element, and then the additional curvature of simply supported truss girders caused by the slip effect under uniformly distributed load was deduced. Then the conjugate beam method was used to calculate the mid-span deflection. The formula results were compared with the experimental and Finite Element Method results. It was shown that the analytical solution agrees well with the experimental data, and can provide theoretical basis for the study and the engineering application of the truss girders.