Calculation of wind forces on lattice structures made of round bars by a local approach

Abstract

In this paper, the aerodynamic loads on simplified lattice structures are evaluated as the sum of the force on each individual member rather than using conventional methods accounting for the overall truss through solidity ratio and global shielding coefficients. Wind tunnel tests were conducted on a single cylinder to determine the aerodynamic force coefficients and the velocity profile in its wake. Aerodynamic forces were measured on 5 models of regular lattices made of round bars. An empirical local method was developed in order to calculate the wind forces on lattice tower based on the forces acting on each individual members and considering the shielding effect. The wind forces on the 5 truss models calculated with this method compare very well to the results from wind tunnel tests and the difference with experimental tests is similar or smaller to the one obtained with the various design documents. Because it accounts for the shielding effect on each member individually, the approach presented appears to be promising for the calculation of wind forces on complex lattice structures at various angles of attack.