Design Calculation of Deflection Curves of I‐Section Steel Beam With Longitudinally Profiled Flanges Under Concentrated Load

ABSTRACT Welded I‐beams with longitudinally profiled (LP) flanges (where LP steel plates are utilized as flanges) can be used to achieve structural optimization. However, its variable stiffness property poses a challenge for deformation design, which requires the formulation of computational equations. In this paper, the theoretical solution of the deflection curve under concentrated load at any position is derived using the unit load method and the mathematical integration method. The accuracy is verified by comparing with the finite element (FE) model. Further, a coefficient is introduced on the basis of the traditional flexural curve expression, and a simple design formula for the flexural curve is proposed by combining the location and coordinates of the load action, and the fitting coefficient is determined by fitting a nonlinear surface to a large number of theoretical results. The results show that the bending deformation MRE corrected by the bending deformation correction coefficient β is only −2.0%, which shows that the bending deformation correction coefficient has good accuracy and simplicity. The welded I‐beam with LP flanges elastic deformation design formulas established in this paper can be applied to the actual construction design of building and bridge structures, which will also promote the application of such advanced steel products.