On the uniform torsional rigidity of square concrete-filled steel tubular (CFST) sections

There are a number of scenarios in which structural members experience torsion, including under the direct application torsional loading, when transverse loading is applied at an eccentricity to shear centre and as second order effect arising from lateral instability. To date, rigidity concrete-filled steel tubular (CFST) sections has yet be fully explored; hence study into uniform square CFST presented herein. First, strain energy formulated, longitudinal warping displacement assumed have undetermined constant. The constant then deduced by means principle minimum energy, thus analytical expression for obtained. accuracy derived formula verified against existing theoretical solutions simplified scenarios, test data results numerical simulations. Finally, influence key parameters analysed, design presented.