During a building project, designers and engineers must consider the impact of wind. Whether simply determining design loads or trying to optimize the aerodynamic effects of the building structure and surroundings, wind analysis can pose a challenge.
Wind load on a structure depends on several factors including wind velocity, surrounding terrain, and the size, shape, and dynamic response of the structure. Traditional theory assumes that horizontal wind load pressures act normally on the face of the structure. Computations for wind in all directions are calculated to find the most critical loading condition.
Consideration of suction from pressure differential forces caused by wind is also typically estimated in the case of sidewalls and leeward walls. Typically, building codes allow for either calculated wind loads, or wind loads determined by testing of models in a terrain setting equivalent to that of the building site.
Ideally, a designer could easily apply wind scenarios while developing design concepts and details. The ability to envision how the airflow translates to positive and negative pressure forces could help designers identify problems or opportunities early on. Translating those pressures to design loads would give the benefit of supporting structural analysis of the design.
This is the concept behind the wind simulation tool available in Autodesk Robot Structural Analysis Professional. The tool offers designers a quick and easy method of testing the effects of wind on their structure. By simply inputting the wind direction and speed (as a constant velocity or as a boundary layer profile) or pressure, users can obtain rapid results on surface pressures and resulting structural loads. Changes can be made, and results rerun in a matter of minutes, enabling the investigation of numerous scenarios.
The Wind Loads Simulation feature enables structural engineers to simulate airflow around their structure and to generate wind loads automatically. This feature is especially useful with structures that are geometrically complex, and for which it is usually difficult to define accurate wind loads. The Wind Loads Simulation feature acts as a virtual wind tunnel, displaying colored pressure maps on the model in order to facilitate visualization and understanding of wind effects.
Robot Structural Analysis Professional 2021 offers enhancements to wind load simulations.
In the 2021 release, you can now specify whether to apply pressure as an average load for a panel or as a detailed pressure along a finite element mesh. If you opt not to apply the average load, you will obtain a detailed picture on how the pressure will be distributed. This is particularly useful for wind loads generated on complex objects.
With more detailed pressure results, structural engineers can better predict and design for wind load effects, thus avoiding potentially costly design changes.