Dynamic Behaviour of a Fixed-end Square Hollow Section Steel Column Subjected to Wind Flow

Abstract

Steel lattice structures are widely used in the structural engineering. These structures are light in weight and usually all structural elements are exposed to wind. This forms that fact that wind loads are highly dependent of the cross-section of structural elements. Although there are several design codes available for assigning wind loads on lattice structures such as Eurocode - EN 1991-1-4 (2005), the resulted assigned wind loads in these codes are conservative and considering the upper bound solution. Additionally, these codes do not provide clear procedure for investigating the dynamic behaviour of the lattice structures. Therefore, this project has been directed towards investigating the dynamic behaviour of a fixed-end square hollow section steel column under wind flow. To carry out this project, finite element analysis (FEA) and computational fluid dynamics (CFD) analysis were coupled. The first analysis was built using Abaqus, where the material and boundary conditions of the column were assigned. The second analysis was composed of two steps, where the first step has been aimed to carry out a quasi-steady simulation using STAR-CCM+. Whereas, in the second step, codes of Abaqus and STAR-CCM+ were coupled. As expected, the column under wind loading will have wind-induced vibration frequencies in both directions (X and Y). The major frequency (in X-direction) is less dependent on mesh size and Time-step. Nevertheless, the minor frequency (in Y-direction) is highly dependent on the mesh size and Time-step, and has lower amplitude. Finally, calculation according to Eurocode reveals conservative results in comparison with the numerical solutions.