Has anyone ever had to do wind loading calculations on a model? I have a product that is designed to go on the top of a lamp post and the client wants to know the wind loading calculations.
Not a clue where to start!
You might find some of these useful:
First thing is make sure you are legally qualified and insured to sign off on the drawings and design, because if it is on a lamp post , it will/may one day fall on the general public and then you are in big shit.
Where are you? In the UK ,it all has to be signed off by a structural engineer who has the relevant experiance in using the correct codes for location and heigh to match expected wind speeds..
It is just not worth losing sleep over it, get the client to pay for a relevant qualified engineer to sign it off.
Jonathan
>It certainly is something that is quite involved when you start doing a bit of Google work on it.
The product is a CCTV unit that goes on the top of a lighting column (or specialised column) and the customer is looking at getting some figures as to the kind of additional loading they will need to provide for by having the unit up there. They have a wide range of lighting columns available to them so I would always advocate the bigger the better as "whip" will always be a factor with a moving unit.
In my ignorance I assumed there would be a standard formula along the lines of surface area x wind velocity = magic answer. From what I have read the other factors of air pressure etc play a massive part in the calculations.
I am > >
The standard codes that a building structural engineer will look at are not really designed to help with something as small as a CCTV camera. You will be able to get a feel for the direct pressure loading due to windspeed. The web will give you average windspeeds at differnt heights in different parts of the UK - I'll have to see if I can relocate the link. I doubt the second order effects are really worth bothering but that sort of assumtion is how things go wrong !! Try CCTV camera suppliers an see if they have any recommended fasteners and brackets for different locations.
If you client makes lighting columns, don't they have the inhouse expertise to appraise the wind loading of various lamp housings on the top of their posts? A CCTV housing would be similar - I think.
Jonathan
You can try ANSI/TIA/EIA 222 standard. That is the standard that governs towers and antenna poles. The calculation method in there is taken from an ASCE book that has a lot of wind loading information.
As someone mentioned above, the best place may be to go to the camera manufacturer and tell them that you need the wind load rating capability. If the laws in the UK is anything like the US this means that the Manufacturer is the one that is ultimately responsible. Actually this makes more sense because the engineerin for the camera's can be spread out of a large number of camera's. A Structural Engineering Analysis here in the States is more for custom, one of a kind and unique situations not something that comes out of a box. In the States the UL sticker on the camera would not apply but the European standard takes in a lot more of the physical issues of products and if the camera is properly rated then this work could already be done.
One other comment is that someone mentioned the average wind load. What is really needed is the maximum wind load that has been accepted by the appropriate regulatory agency.
Assuming that the product is properly rated then a good assumption is that if the mounting holes that are provided with the camera are all utilized, (ie. proper size and number of fasteners) in an appropriate manner then this should be good.
Now, as a rule of thumb I have been told that here in the states that the structure should be able to withstand 50 pounds per sq foot. Again, this is only a rule of thumb and a smaller item would have less "effective" area then a flat wall but it is unlikely that the camera has more then 1 sq foot of area, (unless it is a massive camera and housing) and it is hard to imagine that standard mountings etc. would not be able to handle 50 pounds. So, there is a good chance that this is a very low probablility of failure but the camera manufacturer should definately certify their product. If not then you should find a different manufacturer.
Hope this helps.
Ed
Hope this helps
It is also fairly safe to assume that if the camera comes with
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