Wind Loading / Pressure (BS6399-2:1997)

Wind Load Calculation

RWDI Anemos has the best available knowledge of the British Standard on wind loading BS6399-2:1997. One of our Directors, Nick Cook, was the principal author of the Standard and has authored two definitive books on design against wind loading ("The Designer's Guide to Wind Loading", Parts 1 & 2) as well as a recent Handbook for Designing with BS6399-2:1997. Between him and our other Director, Paul Freathy, well over 40 courses have been run to teach designers and engineers how to apply the Standard. Both are also involved with the Wind Engineering Panel of ESDU International, which is a provider of detailed technical information going beyond the scope of a national code.

This depth of experience allows us to draw on the widest possible range of resources to find data applicable to your problem - whether it is a traditional building or something rather more unusual, like the sculptures shown below. Examples of our wind load calculations include:

Wind Tunnel Testing (Loading & Pressure)

Wind tunnel measurements are often used to determine extreme design values of mean and gust pressure loading. Such measured values are often lower than code values, because of the inherent conservatism in codes, and so pay for themselves many times over in reduced specifications. For the Singapore Arts Centre, (shown here) averaging over different areas was also carried out because of the flexible nature of the roof construction. Such projects used to be carried out using multiple Scanivalve systems - an electro-mechanical multiplexer. Nowadays RWDI Anemos employs more sophisticated techniques using solid-state pressure transducers electronically multiplexed. This system works much faster and allows simultaneous measurements of pressure in different locations. Simultaneous pressures are especially useful in situations where dynamic response may occur or where pressures are to be averaged over different areas.

In the UK we have a wide range of facilities including a new, purpose-designed wind tunnel to provide clients with the design information they need, including:

• A wind tunnel with an 8' by 6' working section and long flow development section to grow realistic scaled wind profiles
• An open working section for ease of access and visibility of test models
• A turntable capable of taking models up to 3m in diameter to accommodate larger models
• Hot-wire anemometry equipment for measuring fluctuating wind speeds
• Irwin probe measurements of pedestrian level winds, sand erosion and smoke visualisation
• 256-channel simultaneous pressure measuring system
• Flame ionisation detector to measure gas concentrations in dispersion measurements
• Dynamic base balance for measuring dynamic response
• Digital still and video capabilities, including editing with music, titles and captions

We also have access to two further wind tunnels and a water flume at our offices in Ontario, Canada.