Thin Beam Shear Lag Effect Of Flexural And Torsional Analysis

Thin-walled structures under the same cross-sectional area greater stiffness and moment of inertia, good structural properties, in the modern variety of building structures and bridges are widely used. The mechanical properties to meet the same time, thin-walled structure with a more light weight, can save materials. Can adapt to the social needs of modern energy saving and emission reduction. Box, thin-walled bar groove is widely used in bridges with large span bridges, high-strength needs to play a perfect match. Meanwhile, with the bridge led to the development of thin-walled bar. Research such as the shear lag effect is because the traditional theory of thin-walled structure can not meet the needs of bridge design was gradually built up a theoretical system.Based on the consistency of thin-walled structure theory, the internal force from the energy point of view analysis. Abandoned elementary beam bending theory, included in the thin-walled bridge bending shear effects; introduced just around the assumption that in the case of torsional and included the effects of shear lag. Applied to solve the Hamiltonian system of dual methods, starting with displacement deduced from thin-walled structures of the Lagrange equations, and then Legendre transform it into Hamilton canonical equations were solved. In order to obtain accurate solutions to avoid computer errors in the calculation using the boundary at both ends of the precise integration method. Program written using MATLAB voice to achieve this calculation. System of a thin-walled structure calculation of internal forces and deformation, as a bridge to the design of thin-walled, with the guidance of the project example.This article provides a new analysis of box-section bridge theory method, the preparation of the generally applicable to all forms of thin-walled beam bridge MATLAB. Solve the coupled bending and torsional shear lag in case of the calculation. Theoretical research in this subject simple, high precision engineering examples in the design of the bridge has a certain practical significance.