## 3 Results of Numerical Simulations  
Figure 7 represents the mean distribution of the static pressure on the surface of the crane structure induced by wind. To estimate this distribution or compute the static pressure, the whole external surface of the lattice structure is considered. This picture is for the urban wind profile (\(V_{40}\) = 15 m/s and \(z_{40}\) = 40 m). The jib is perpendicular to the wind direction (\(\theta\) = 90\({}^{\circ}\)). As can be observed, as the vertical coordinate Z (height) increases, the value of the static pressure also increases. This phenomenon is caused by the applied wind profile, where the value of the wind velocity depends on the height. Figure 8a-d shows the components of the aerodynamic forces and overturning moment as a function of the angle \(\theta\). The most important component for further analysis is the \(F_{x}\) component because it causes the overturning of the whole structure. The maximal values are obtained for \(\theta\) = 90\({}^{\circ}\). Figure 6: Details of the automatically generated mesh: (**a**) part of the crane jib with operator’s cabin, (**b**) base of the studied crane with central ballast, (**c**) part of the truss structure of the jib, and (**d**) part of the truss structure of the tower. Figure 8: Components of the aerodynamic forces induced by the wind as a function of angle \(\theta\) for an urban, village, and open terrain (\(V_{40}\) = 15 m/s and \(z_{40}\) = 40 m): (**a**) component \(F_{x}\), (**b**) component \(F_{y}\), (**c**) component \(F_{z}\), and (**d**) overturning moment \(M_{tip}\). Figure 7: Static pressure distribution (urban terrain, \(\theta\) = 90\({}^{\circ}\)). They are equal to \(F_{x}\) = 9220.826 N, 8,480,169 N, and 7783.727 N in the case of open, village, and urban terrain. It is worth noting that in our previous study concerning other lattice structures (scissor lift or fast-erecting crane), the extreme values of the aerodynamic forces are obtained for a slightly different position of the structure for the wind direction. However, in the current study, the jib possesses a more openwork structure in comparison with the previously mentioned ones. The minimal values of the \(F_{x}\) components are obtained when the crane jib is parallel to the wind direction. In this case, the aerodynamic drag force is generated only by the tower (4274.746 N, 3571.366 N, and 2998.246 N, respectively). In turn, the component \(F_{y}\), Figure 8b, takes maximal values for the angle \(\theta\) close to \(\theta\) = 60\({}^{\circ}\), and the values are as follows depending on the wind profile, namely, \(F_{y}\) = 1502.037 N, 1510.663 N, and 1478.181 N (absolute value). As can be seen, these values are very similar. It is caused by the fact that this component of the aerodynamic drag force is caused mainly by the rotating crane jib, while the crane tower is stationary. For the angles \(\theta\) = 0\({}^{\circ}\), 90\({}^{\circ}\), 180\({}^{\circ}\), and 270\({}^{\circ}\), the value of \(F_{y}\) should be treated as equal to 0 N.  
The \(F_{z}\), Figure 8c, is one order of magnitude less in comparison with other components of the aerodynamic drag force. Thus, it can be omitted in further analysis. Finally, the values of the overturning moments are depicted in Figure 8d. Similarly, as in the case of \(F_{x}\), the maximal values of this quantity are reached for \(\theta\) = 90\({}^{\circ}\), and they are as follows: \(M_{tip}\) = 275.572 kNm, 266.554 kNm, and 256.794 kNm for the open, village, and urban terrain, respectively. The minimal values are obtained when the crane jib is parallel to the wind direction (90.862 kNm, 82.514 kNm, and 77.527 kNm). The aerodynamic force and moment coefficients are presented in Tables 2-4.