Advance Design generates climatic loads (wind, snow) on the windwall planar elements.
Wind loads can be generated automatically on windwalls, at both interior and exterior of the building. One can control the permeability of the windwalls by adjusting the Cpe and Cpi (external and internal pressure coefficients) values from the windwalls properties list.
Figure 1 Cpe and Cpi Dialog in windwalls Properties list
Modify the skin permeability μ to alter the internal wind pressure on all windwalls
The internal pressure value can be modified by imposing a value for the permeability of the skin (opening ratio) μ. This value can be different on each direction, but valid on all windwalls, when computing the Cpi coefficient (see chapter 7.2.9 in EC1).
Figure 2 Set an imposed value for μ on one wind direction
Modify Cpe coefficients to alter the external wind pressure on a specific wind-wall
Unlike the Cpi coefficient, the Cpe coefficients may be defined by the user on each wall individually. To do so, the following steps are taken:
1. Generate the wind loads
Figure 3 - Step 1 – Automatic generation of the wind loads
2. Select the wind-wall/s to be modified and enter the desired values for Cpe. Be aware of the wind load directions.
Figure 4 - Step 2 – Adjust the Cpe values
3. Deactivate the automatic Cpe and Cpi calculation in the wind case properties list.
Figure 5 - Step 3 – Deactivate the automatic calculation of the Cpe and Cpi coefficients
4. Regenerate/update the static wind loads. The resulting loads will be affected by the user defined pressure coefficients.
Figure 6 - Step 4 – Update the Wind load case