Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

Designing a resilient and structurally sound roof is important in construction projects, and one crucial aspect that demands is the consideration of wind loads. In this context, the European standard EN 1991-1-4 NF provides a comprehensive framework for determining wind actions on buildings, helping architects and engineers ensure the safety and stability of structures.


Assumptions for the calculation of the loads on a duopitch roof

Wind EN 1991-1-4 NF calculation example for a duopitch roof

Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

Wind EN 1991-1-4 NF calculation example for a duopitch roof

Wind EN 1991-1-4 NF calculation example for a duopitch roof - properties

 

Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

 

Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

CsCd calculation for X+ direction:

h = 7.6284831 m

reevaluate Iv(z) for CsCd at z = 0.6 h = 4.5771 m
but zmin > z => z = 9 m => we don’t need to reevaluate Iv (z), it is the same as above

Wind EN 1991-1-4 NF calculation example for a duopitch roof

External pressure coefficients for duopitch roofs

External pressure coefficients for duopitch roofs

 

External pressure coefficients for duopitch roofs

External pressure coefficients for duopitch roofs

 

 

 

The area of each slope is 207.18738 m2 and the pitch angle is 10.31° so the cpe10 values are extracted from Table 7.4a for X+ direction and Table 7.4b for Y+ direction.

 

X+:       

                  cpe10_1        cpe10_2

 

Also, both values of Cpi values, +0.2 and -0.3 (the default option in the Cpe cpi dialog) are used resulting in 4 load cases for the same direction.

Wind EN 1991-1-4 NF calculation example for a duopitch roof

CsCd is considered the same for the entire building per wind direction. The value for X+ is calculated above.

For the F zones:

 

Like all above the position and the geometry of the loads based on the zones provided by Figure 7.8 on the roof are calculated automatically. All the loads and the load cases are automatically generated.
e = 15.257 m

 

Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

For the F zones:

e = 15.2569 m

 

The resulting loads are:

 

Wind EN 1991-1-4 NF calculation example for a duopitch roof

 

 

Related topics