Internal Wind Load is not a commonly used term in structural engineering. Wind loads typically refer to the forces exerted by the wind on the external surfaces of a building or structure. These loads are calculated to ensure the stability and safety of the structure under wind loading conditions.
If you meant to inquire about internal forces or effects within a structure due to wind, those are typically referred to as wind-induced internal pressures or wind-induced internal forces. These forces can occur due to the interaction of wind with the building’s internal spaces, such as openings, corridors, or ventilation systems. While they are not referred to as “Internal Wind Load,” they are significant considerations in building design.
Wind-induced internal pressures can arise from various phenomena, including:
- Infiltration and Exfiltration: Wind can cause air to infiltrate or exfiltrate through openings, such as windows, doors, or vents. This movement of air can create pressure differentials within the building. The magnitude of the pressures depends on factors such as wind speed, building tightness, and the size, location, and configuration of the openings.
Example: In a building with windows and doors, wind-induced internal pressures can occur. For instance, when the wind blows against a building, it can cause positive pressure on the windward side, resulting in air infiltration through gaps or cracks. Similarly, on the leeward side, negative pressures can develop, leading to air exfiltration. These pressures can affect the performance of the building envelope, ventilation systems, and occupant comfort.
- Internal Pressure Differences: Wind-induced pressure differences between different zones or areas within a building can also occur. These differences can arise due to variations in wind exposure or the geometry of the building. Pressure differences between rooms, corridors, or different levels can influence the airflow patterns, distribution of pressures, and ventilation effectiveness within the building.
Example: Consider a multi-story building with multiple zones or compartments. Wind-induced pressure differences can occur between different floors or sections of the building due to variations in wind exposure or the presence of obstructions. These pressure differences can affect the airflow patterns, air distribution systems, and pressurization of different zones within the building.
Designing for wind-induced internal pressures involves considering factors such as building tightness, openings design, ventilation systems, and the distribution of pressure within the building. Proper ventilation strategies, air balancing, and the use of pressure relief mechanisms, such as vents or dampers, can help manage the impact of wind-induced internal pressures on the building’s performance.
It’s important to note that while wind-induced internal pressures are considered in building design, the primary focus is typically on the external wind loads acting on the structure. These external loads determine the overall stability and structural integrity of the building, while wind-induced internal pressures primarily impact indoor air quality, comfort, and energy efficiency.
