Wind effects on structural intersections

Abstract

The airflow through an unclad lattice structure creates a complex fluid motion which affects the local wind loading of individual members within the framework. Consequently, design loads determined by traditional methods that consider each element as a finite-length member immersed in a uniform flow may be incorrect, particularly at nodal points where the largest disturbance to flow occurs. This paper, therefore, presents details of the wind effects on perpendicular structural intersections composed of either two circular cylinders or two square-section bars. The investigation was performed in a low-speed wind tunnel and models of each configuration were immersed in a steady, low-turbulence, uniform approach flow. Distributions of surface pressure were measured at a Reynolds number of 2 × 10 4, and these revealed that the wind effects are dependent upon section type, and whether the members intersect in a single plane or are fixed one behind the other with a point of contact.