Trussed Frameworks and Plate Girders

This chapter reviews the aerodynamic behavior of trussed frameworks and plate girders, including single trusses and girders, systems consisting of two or more parallel trusses or girders, and square and triangular towers. Test results are presented from several sources with a view to allowing an assessment of the errors that may be expected in typical wind tunnel measurements. Throughout the chapter, the aerodynamic coefficients are referred to and used in conjunction with the effective area of the framework. The depth (along‐wind dimension) of the framework should be assumed to be zero in order not to overestimate the favorable effect of the imperfect along‐wind cross‐correlations of the fluctuating loads. Finally, the area of the framework per unit height at any given elevation, used to estimate the mean and the fluctuating drag forces, should be equal to the effective area per unit height at that elevation.