Dynamic influence (CsCd) generation on the pole structure can happen in case all of the following conditions are satisfied:
- Technical module No. 176 (Wind load 1D Elements) is enabled;
- Structure is defined as 2D Frame, 2.5D Frame or 3D Frame;
- Structure is designed using the structural steel material;
- Load generator wizard is used;
- Generation of the dead loads is selected;
- Generation of the wind loads is selected;
- Elements for the generation of the wind load are defined as Pole structure(s).
The dynamic effect of the wind on the pole structure is accounted by the structural factor CsCd (NEN-EN1991-1-4#6.2), which is usually calculated at the pole structure’s highest place (node).
The dynamic effect causes the increase of the wind pressure due to turbulence in resonance with the structure. Increasement is taken into account by using resonance response factor R2 can be calculated according to NEN-EN1991-1-4#Annex(B) or NEN-EN1991-1-4#Annex(C);
Calculation of the resonance response factor R2 requires the determination of the decisive (lowest) natural frequency of the structure N1 and the equivalent mass Me (NEN-EN1991-1-4#Annex(F)) can be determined by the dynamic analysis. Mentioned dynamic factors for the pole structure should be generated/calculated according to the global axis, i.e. N1;x, Me;x in 2D case and N1;x, N1;y, Me;x and Me;y in 3D case. Dynamic factors N1 and Me for the pole structures can be generated using MatrixFrame® wind load generator engine by the persistence of the dead load, clearly defined pole type elements and CsCd grid parameters (CsCd button of wind load generator) as:
| Parameter | Description | Reference | Default value |
| Gy | Constant | NEN-EN1991-1-4#Table C.1 | Uniform |
| Gz | Constant | NEN-EN1991-1-4#Table C.1 | Uniform |
| DeltaS | Logarithmic decrement of structural damping | NEN-EN1991-1-4#Table F.2 | 0.02 |
| k | Equivalent roughness | NEN-EN1991-1-4#7.9.2 | 0.05 |
| Phi | Solidity ratio | NEN-EN1991-1-4#7.13 | 1.00 |
| N1 | Lowest natural frequency of the structure | Calculated/generated by MatrixFrame® dynamic analysis or user input | Calculated/generated by MatrixFrame® dynamic analysis or user input |
| Me | Equivalent mass | NEN-EN1991-1-4#F.14 | Calculated/generated by MatrixFrame® dynamic analysis or user input |
| DeltaD | Logarithmic decrement of structural damping due to special devices | User input | 0.00 |
The generated factors are represented in the load calculation table.
Generated and/or calculated dynamic effect-driven factors influencing only the wind load magnitudes applied on the pole element(s).
Antenna-effective areas for wind exposure can be found or entered into the nonstructural elements table as follows:
After turning the antenna at the intended angle using a wind loads generator for nonstructural elements, the effective area of the antenna is treated as follows:
Using a wind loads generation for rotated wind load attack action generates two global axis-oriented components of the wind action:
