## 5 Numerical Analysis Results and Comparison of Strong Wind Analysis with Real Tornado Action
### High Wind Speed Load, T1, T2, T3
#### 5.2.2 Analysis of Internal Forces  
The exact values of the internal forces (stresses, bending moments, shear force, and normal force) are presented in Table 5. Three main sub-tables have been prepared, each of which applies to the wind with a different direction of action: W1, W2, W3 (see Section 4.3.1). The data have been divided according to the type of load (permanent load or wind load, which has been divided according to the speed starting from 22 m/s (LWS) to 55.13 (T3)). The summary focuses mainly on stresses (The assumption is to compare the stresses obtained with the bending strength of C24 wood). The highest obtained stress equal to 32.09 MPa was obtained for the speed of 55.14 m/s in the W2 direction, which significantly exceeds the allowable strength of 24 MPa. According to Section 4.3. (load analysis) we can compare the bending strength with the stresses in the element. For comparison, the value of 24 MPa was adopted as the characteristic strength of wood. From Table 5 it can be observed that the smallest value of wind speed that generates exceeding this value is the speed of 49.44 m/s in the case of wind W2. The stress value achieved is 25.91 MPa, which exceeds the strength by 8%. This supports the assumption that the tornado that destroyed the facility is at the turn of the EF1 and EF2 groups on the extended Fujita scale. Unfortunately, the destructive wind speed \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Load**} & \multicolumn{2}{c}{**W1**} & \multicolumn{2}{c}{**W2**} & \multicolumn{2}{c}{**W3**} \\ \hline \multirow{2}{*}{**Type**} & & **Value** & & **Deflection** & **Deflection** & **Deflection** \\ \cline{2-7}  & **[kN/m\({}^{2}\)]** & **[kN/h]** & **[m/s]** & **[mm]** & **[mm]** & **[mm]** \\ \hline Dead load—Roo covering & 0.48 & - & - & 0.1 & 0.1 & 0.1 \\ Wind LWS & - & 79.2 & 22.00 & 1.4 & 1.3 & 1.1 \\ Wind T1 & - & 158.0 & 44.89 & 5.6 & 5.6 & 4.3 \\ Wind T2 & - & 178.0 & 49.44 & 6.8 & 6.9 & 4.8 \\ Wind T3 & - & 198.5 & 55.14 & 8.3 & 8.5 & 5.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Tabular list of displacement values for winds W1, W2, W3. Figure 12: Deformation of the roof structure: (a) the entire roof structure, andthe most loaded pair of rafters ((b)—W1, (c)—W2, (d)—W3). cannot yet be unequivocally estimated; thus, further analyses of other structural elements have been carried out to check at what speed they will be destroyed. Knowing the angle of inclination of the roof and using basic trigonometric formulas, we can convert the internal forces from the rafts to those occurring on the wall plate (Figure 13). Based on the previous results (tables from Point 6.2), the maximum values of shear forces and normal forces were assumed. These forces have the direction of the vector consistent with the local arrangement of the rafts. Therefore, in order to calculate the vertical force in the anchor, it was necessary to add up the cosine of the shear force with the sine of the normal force. Figure 13: Comparison of the internal forces of the rafts (T, N) and those occurring in the wall plate (\(F_{2}\), \(F_{x}\)).