Using the SkyCiv Load Generator for ASCE 7-22 Wind Load Calculations
Using the new version of the SkyCiv Load Generator, the wind pressures in accordance with ASCE 7-22 can be generated by selecting the process is to define first the code reference (which is ASCE 7-22) and the unit system to be used (Imperial or Metric). From there, the workflow is to define the Site Data, Structure Data, and Wind Load Data. Free users can only use the calculation for a gable and open pitched/duopitched roof for a maximum of 3 solves per week. With a Professional Account or by purchasing the standalone Load Generator module, you can use all the features of this calculation as long as you want You can purchase the standalone module thru this link.
Users will need to define the parameters from top to bottom. The subsequent sections will detail the input parameters that you will need to define to generate the wind results. After selecting the design code, it will automatically open the Site Data menu so you can enter the location of the structure you are designing.
Figure 1. SkyCiv Load Generator v2 UI.
Site Data
Users can get the wind speed by location at any time from the SkyCiv wind speed map database. Using ASCE 7-22, you just need to define the Risk Category of the structure and put the Project Address located in the USA. If the location is outside USA, and the load calculation/reference code is similar to the ASCE 7-22, you can define the Risk Category, put the location, and just manually put the Basic Wind Speed value. You should still be able to use the ASCE 7-22 wind load calculation by doing this.
Note that some wind contours were extrapolated to provide an accurate calculation of wind speeds.
SkyCiv has digitalized the map as per the paperback standard. This means, you can simply enter in the site location and the software will automatically pull the wind speeds based on this input. There is a limit to how many times the wind speed can be calculated on the free tool. The software will use our internal interpolator to calculate values between the contours, to ensure accurate wind speeds are used in your designs.
Structure Data
The next step is to define the Structure Data. You can select from Building, Freestanding Wall/Solid Signs, Solar Panels, and Rooftop Equipment/Structure. You just need to provide the structure dimensions and other data to proceed with the next step. The structure options are as follows:
- Building – supports the following roof profile:
- Gable, Hip, Monoslope (enclosed, partially enclosed, or partially open)
- Troughed, Pitched, Open Monoslope (open)
- Freestanding wall/Solid signs
- Freestanding wall – for Wall Height value equal to Ground to Top dimension
- Solid sign – for Wall Height less than the value of Ground to Top dimension
- Solar Panels
- Rooftop
- Ground (array)
- Rooftop Equipment
- Open Signs/Frames
Figure 3. Structure Data of SkyCiv Load Generator.
Wind Load Parameters
After complete the Structure Data input, the next step is to click the Checkbox beside the Calculate Wind Load button, and then click this button. Inside the Wind Load Data, all you need to do is define each parameter from top to bottom. You need to select first the Exposure Category of the location and the Wind Direction. The Wind Direction parameter is used in obtaining the upwind (left side) and downwind (right side) ground elevations to calculate for Topographic Factor, Kzt.
Figure 4. Load options for ASCE 7-22.
For Professional users including those who purchased the standalone version of the Load Generator, the View Design Wind Inputs for All Directions will be automatically generated. With this they can compare what wind source direction will yield the worst case (or the highest design wind pressure) that they can use in the design of the structure.
Figure 5. Automatic initialization of the Design Wind Pressures for all directions for paid users.
Figure 6. The generated design wind speed or pressure for all directions table to determine the worst wind source direction to be used in the design.
In version v6.6.0, we’ve introduced the automatic building detection for the site to automate exposure category analysis for each wind direction using Overpass API and Microsoft Global Footprint Data. If the building data are missing some areas, there is an option to use our trained AI model to detect these building footprints on the map. The algorithm uses the area and height of the building from the data sources to analyze the obstructions inside each direction sector.
Figure 7. Automatic building detection in Load Generator to determine the Exposure Categories.
Figure 8. The generated Exposure Categories for all wind directions based on the analyzed building footprint data.
Users also have the option to edit the data points in the Elevation chart that are used to calculate the Topographic Factor, Kzt for the selected wind source direction.
Figure 9. Elevation chart for the selected wind source direction.
Topography Input Parameters
Exposure Category – Used in calculation of Velocity Pressure Coefficient Kz and Topographic Factor, Kzt . Assumed to be homogenous for each wind source direction
Wind Source Direction – used to obtain the elevation data on a specific direction section of the area. These elevation data are used in determining the Topographic Factor, Kzt
Type of Terrain – Options to select Flat, Hill, Escarpment, Ridge
H – Height of obstruction/terrain. For type of terrain is set to option other than Flat terrain, this is used in calculating the Topographic Factor, Kzt
Lh – Horizontal distance from peak to the middle height of the obstruction. For type of terrain is set to option other than Flat terrain, this is used in calculating the Topographic Factor, Kzt
x – Horizontal distance of structure to the peak of the obstruction with the peak as the point of reference. For type of terrain is set to option other than Flat terrain, this is used in calculating the Topographic Factor, Kzt
Figure 10. Topography Parameters for ASCE 7.
Wind Input Parameters for MWFRS
Type of Structure – Required to be set to ASCE 7 Buildings – Main Wind Force Resisting System (MWFRS)
Enclosure Classification – Enclosed, Partially Enclosed, Partially Open (ASCE 7-16 and ASCE 7-22) options for gable, hip, and monoslope roof; Open for pitched, troughed, open monoslope roof. Used in obtaining the internal pressure coefficients Cpi
Wind Blockage – For calculation of GCN for open roof profiles
Is building elevated? – (For ASCE 7-22) Option to add the elevated height of the structure for calculating the design wind pressures acting below the structure
Height to Top of Parapet – (Optional) used for calculating the velocity pressure at the top of parapet and obtain the design wind pressure acting on the parapet
Floor Elevation – Since the wind pressure acting on the windward is parabolic in nature, this is used to approximate this pressure by assigning multiple rectangular pressure acting on the wall in between the level
Calculate Gust-effect Factor – (Optional) By default, this option is set to “Assumed rigid (G=0.85).” For flexible structures, or if needed, the detailed procedure for calulating the Gust-effect factor will be used when this option is set to “Detailed”.
Natural Frequency of structure, n1 – Required when detailed Gust-effect factor is selected.
Damping Ratio, β – Required when detailed Gust-effect factor is selected.
Figure 11. Wind Parameters for MWFRS.
Wind Input Parameters for Components and Cladding
Type of Structure – Required to be set to ASCE 7 Buildings – Components and Cladding
Enclosure Classification – Enclosed, Partially Enclosed, Partially Open (ASCE 7-16 and ASCE 7-22) options for gable, hip, and monoslope roof; Open for pitched, troughed, open monoslope roof. Used in obtaining the internal pressure coefficients Cpi
Wind Blockage – For calculation of GCN for open roof profiles
Effective Area of Wall Cladding – Can be a comma-separated value (i.e. 23,44,20) for multiple effective wind area. Used in calculating the design wind pressure for wall cladding or components
Effective Area of Roof Cladding – Can be a comma-separated value (i.e. 23,44,20) for multiple effective wind area. Used in calculating the design wind pressure for roof cladding or components
Height to Top of Parapet – (Optional) used for calculating the velocity pressure at the top of parapet and obtain the design wind pressure acting on the parapet
Consider Attached Canopy? – (Optional) used for calculating design wind pressure for attached canopies
Mean Canopy Height – (Optional) used for calculating design wind pressure for attached canopies
Mean Eave Height – (Optional) used for calculating design wind pressure for attached canopies
Floor Elevation – Since the wind pressure acting on the windward is parabolic in nature, this is used to approximate this pressure by assigning multiple rectangular pressure acting on the wall in between the level
Figure 12. Wind Parameters for Components and Cladding.
Or you can select the combined MWFRS and Components and Cladding in one solve:
Figure 13. Option for combined MWFRS and Components and Cladding calculation.
After all these parameters are defined and confirmed, the next step is to click the Calculate Loads on the left side of the UI.
Results
Once all the parameters are defined, clicking the Calculate Loads button will give a result as shown in Figure 14.
Figure 14. Wind load results for MWFRS.
Figure 15. Wind load results for Components and Cladding.
The summarized results are shown on the middle of the screen. Other results are shown on the detailed report such as the parapet, canopy, elevated structure pressures, approximate base shear, and many more.
Detailed Calculation
The detailed wind load calculations can be accessed only by Professional account users and those who purchased the standalone load generator module. All the parameters and assumptions used in the calculation are displayed on the report to make it transparent to the user. You can download a sample detailed calculation thru this link.
For additional resources, you can use these links for reference:
