L-shaped plate model for the analysis of the warping deformation of perforated diaphragms in box girder

Abstract

In order to estimate accurately the warping deformation of perforated diaphragms in girder distortion, a model of L-shaped plate is proposed in this paper based on the symmetry for the structure and loading, and the warping behavior under concentrated load at corner is investigated. The L-shaped plate is seen as an assembly of three rectangular portions connected by undetermined displacements and moments along the common boundary. Analytical functions for warping displacements of each rectangular portion are constructed according to elastic plate theory, and closed-form solutions are derived based on boundary conditions and compatibility between portions. Verifications are conducted by employing Finite Element Method and agreeable resultants are demonstrated for warping displacements and in-plane stress components, especially for the stress concentration around the corner of the cutout. Besides, a cutout ratio ρ is introduced to testify the feasibility of plate theory in solving the warping deformation of L-shaped plate. Results show that the rational range of cutout ratio for the model of L-shaped plate is identified 0.13<ρ < 0.25, and the variation of the shape of cutout hardly makes any significant influence on the warping deformation at loading corner for L-shaped plate.