Response of Thin Walled Double Spine Mono-Symmetric Box Girder Structures to Torsional-Distortional Loads

Chidolue C.A, Nwokoye O.S

In this work, the response of thin-walled double spine mono-symmetric box girder frame to torsional and distortional loads was studied using Vlasov’s theory of thin walled structures. The potential energy of the system at equilibrium was used to obtain the governing differential equations of equilibrium for torsional-distortional analysis of the box structure, by minimizing same using the principle of variational calculus and Euler-lagrange equation. The torsional-distortional strain modes interactions were considered and used to obtain the coefficients of the governing differential equations of equilibrium which were solved using method of Fourier sine series to obtain the torsional and distortional displacements of the box girder section. The maximum torsional and distortional displacements of the 20m simple supported box girder were found to be 2.97mm and 8.77mm respectively.