[TAIWAN2014] Building Wind Loads Generator

Intro

TThis plug-in automates the calculation of  static wind loads in accordance with the  TAIWAN(2014) standard for enclosed building. It allows engineers to input wind design parameters and instantly visualize height-wise wind pressure and force distributions, streamlining the wind load design process.

Developed with

Applicable standards

Benefits of this plugin

How to use this plugin?

1. On the left, users input wind design parameters of your structural model .

   

2. On the right, the plugin instantly visualizes results such as Design Wind Pressure,Story Force, Story Shear, and Overturning Moment in both X and Y directions using charts and tables.

   

3. Once all parameters are set, go to the “Load Cases to Apply to Wind Loads” tab.
   Here, you can select the Static Load Cases where the seismic loads will be applied for each direction.

   

4. Finally, click the “Apply Wind Loads” button to assign the calculated loads to your structural model.

   

Note

Wind Design Paramters

① Basic Wind Speed (V₁₀)
Enter the basic wind speed at 10 meters height for the structure's location. This value represents the 10-minute mean wind speed with a specific return period (typically 50 years). Refer to the Taiwan wind speed map or local wind regulations for your site. Refer to 2.4 基本設計風速.

② Exposure Category
Select the terrain roughness category that best describes the site surroundings. Refer to 2.3 風速之垂直分布 and 表2.2 地況相關參數
- Category A : Urban city centers where at least 50% of the buildings have heights greater than approximately 20 meters.
 - α = 0.32, Zg = 500m, Zmin = 18m
- Category B (Suburban): Urban suburbs, small towns, or areas containing numerous buildings with heights ranging from approximately 10–20 meters, or rural areas with dispersed low-rise buildings.
 - α = 0.25, Zg = 400m, Zmin = 9m
- Category C : Open flat terrain, grasslands, coastal areas, or lakeshore regions where the height of obstruction elements is less than approximately 10 meters.
 - α = 0.15, Zg = 300m, Zmin = 4.5m

The exposure category affects the velocity pressure exposure coefficient K(z) calculation.

③ Importance Factor (I)
Define the importance factor based on the building's occupancy and function. This factor accounts for the importance of the structure. Refer to 2.5 用途係數.

④  Mean Roof Height (hn)
The average height of the roof above ground level. This value is automatically extracted from the structural model's story data and represents the maximum elevation in the model.

This parameter is crucial for:

- Velocity pressure exposure coefficient K(z) calculation
- Gust effect factor determination
- Topographic factor assessment

⑤ Topographic Factor (Kzt)
Click the "Topographic Settings" button to account for wind speed-up effects due to hills, ridges, or escarpments. This is optional and applicable when structures are located on elevated terrain. Refer to 表2.3(a),(b),(c).

For each direction (X and Y), specify:

- Hill Shape: Ridge(山脊), Escarpment(懸崖) and Hill(山丘)

- Hill Height (H): Vertical height of the hill/ridge

- Hill Length (Lh): Horizontal distance from crest to where ground elevation is half the hill height.

- Crest-Building Distance (x): Horizontal distance from hill crest to the building

  - Positive if upwind of crest, Negative if downwind of crest

The plugin calculates:

- K1: Based on H/Lh ratio and hill shape, Refer to 表2.3(a)
- K2: Based on x/Lh ratio and hill shape, Refer to 表2.3(b)
- K3: Based on z/Lh ratio and hill shape, Refer to 表2.3(c)

If topographic effect is not considered, Kzt = 1.0 for all stories.

⑥ Structure Type
Select the structural classification. 

Rigid Structure :  Buildings with fundamental frequency > 1 Hz

- Typical low-rise to mid-rise buildings
- Simpler gust effect factor calculation

Flexible Structure: Buildings with fundamental frequency ≤ 1 Hz

- Tall or slender buildings
- Requires natural frequency and damping ratio input
- More detailed dynamic response consideration
 

⑦ Gust Effect Factor (G or Gf)
Click the "Gust Effect Factor Calculator" button to compute the gust effect factors for X and Y directions. Refer to 2.7 陣風反應因子.

For Rigid Structures: Input required.

- B: Building width (perpendicular to wind direction) 
- L: Building length (parallel to wind direction) 

The calculator automatically determines:

- Turbulence intensity (Iz)
- Integral length scale (Lz)
- Background response factor (Q)
- Gust effect factor for rigid structure: 

For Flexible Structures :Additional inputs required:

- Natural Frequency - X [Hz]: First mode frequency in X-direction
- Natural Frequency - Y [Hz]: First mode frequency in Y-direction
- Damping Ratio: Structural damping (typical: 0.01-0.03)

The calculator includes resonant response effects:

⑧ Building Width and Depth (b × d)
Define the plan dimensions of the building to determine shape factor and effective area for wind pressure application.
 

⑨ Load Cases to Apply to Wind Loads
Select the static load cases from your structural model where wind loads will be applied:

- Load Case for X-Direction: Assigns wind loads acting in the global X-direction
- Load Case for Y-Direction: Assigns wind loads acting in the global Y-direction

Important: The two load cases must be different to avoid overwriting.

Design wind pressures
The design wind pressures, in pascals (or user-specified force/area units), are calculated from the following equations:

Basic Wind Pressure, q(z)

where:

- Unit :  kgf/m² (wind pressure constant, automatically converted to user's unit system)
- I : Importance Factor
- V₁₀ = Basic Wind Speed
- K(z) = Velocity pressure exposure coefficient at height z
- Kzt = Topographic factor

Velocity Pressure Exposure Coefficient, K(z)

where:

- z = Height above ground (elevation of each story)
- Zg = Gradient height (depends on exposure category)
- α = Power law exponent (depends on exposure category)

Note : For z ≤ 5m, z is taken as 5m for calculation purposes.

Design Wind Pressure

1. Design wind pressure on the windward face is calculated as:

p1(z) = q(z) × G or Gf × Cpe,windward - q(h) x (GCpi)

2. Design wind pressure on the leeward face is calculated as:

  p2(z) = q(h) × G or Gf × Cpe,leeward - q(h) x (GCpi)

The design wind pressure acting on the building in the wind direction is:

p1(z) - p2(z)

where:

- q(z) = Wind pressure at height z meters above the ground 
- q(h) = Wind pressure at height z = h meters above the ground 
- G of Gf = Gust effect factor defending on structure type
- Cpe,windward = External pressure coefficient for windward face =0.8 
- Cpe,leeward = External pressure coefficient for leeward face (varies with L/B ratio)
- Internal Pressure Coefficient, GCpi = 0.375 (Enclosed Buildings)

External Pressure Coefficient (Cpe,leeward) - Refer to 表2.4 牆之平均外風壓係數

The leeward pressure coefficient is determined by linear interpolation based on the L/B ratio:

Story Wind Force

Story Force = Design Wind Pressure × Story Height × Building Width

where:

- Story Height = Exposed height of each story
- Building Width = LOADED_BX (for X-direction) or LOADED_BY (for Y-direction)

Story Shear and Overturning Moment

- Story Shear = Cumulative sum of story forces above the current level

- Overturning Moment = Cumulative moment from story shears and inter-story heights

Calculation Flow Summary

1. Input Parameters : Basic wind speed, exposure category, importance factor, structure type
2. Height Coefficients : Calculate K(z) for each story based on elevation and exposure
3. Topographic Effects: Calculate Kzt if terrain effects are considered
4. Gust Response: Determine gust effect factor (G or Gf) based on building dimensions and dynamic properties
5. Pressure Coefficients : Assign Cpe values for windward and leeward faces
6. Basic Wind Pressure : Compute wind pressure at each story level
7. Design Wind Pressure: Apply gust effects and pressure coefficients
8. Story Forces : Calculate lateral forces considering story geometry
9. Shear & Moment: Accumulate forces to obtain story shears and overturning moments
10. Visualization : Display results in graphs and tables
11. Export/Apply : Send loads to structural model or export to Calc.Excel Sheet

Conclusion

•  
  • This plugin provides a comprehensive and user-friendly environment for generating static wind loads in compliance with TAIWAN 2014 Building Code.
  • By guiding users through standardized parameter inputs and offering dynamic visual feedback, it ensures transparency in the wind load design process. Engineers can better understand how key inputs—such as wind speed, terrain exposure, topographic effects, and gust response—impact the story-wise pressure and force distribution, enhancing both design quality and decision-making efficiency.
  • The support for both rigid and flexible structures, along with optional topographic effects, makes this tool versatile for a wide range of building types and site conditions in Taiwan.
  • The seamless workflow from input to visualization and export significantly reduces manual effort and promotes standardized, reproducible outcomes in structural wind load design.