Any guidance on design forces for a reinforced concrete labyrinth weir would be very much appreciated. I will have data on flow velocities, height of water over weir etc. I know it's a complex subject...
Thanks for any help.
Thanks for replying. Yes, you are quite right there are typo's in several of the equations for K but I have sorted that out. The K values used for the example in the book are more or less correct.
I have contacted Prof Irvine to see what he says and will post his reply in due course.
Thanks Josh,
No, I'm not confusing weight and mass, though it's a common mistake as you rightly say ! I am using the data given in the book.
Thing is, the result in the book looks suspicious anyway: a fundamental period of 0.43s for a 120m tall tower.
Hi guys (no pun intended)
I have been reading up on guyed tower dynamics - lots of literature - excellent treatment given in 'Cable Structures' by Max Irvine. However, when I try to rework his Example 4.3 while my guy stiffness results agree pretty well with his and the mode shapes are exactly...
Hi Guys,
I've been retired from the oil industry for a few years and now a bit out of touch but having to revive something for a design job. Is API RP-2A WSD still in use generally ? I think the last edition was 21st. Or is everyone using LRFD ?
Any comments/ info would be very much...
Hello Sk90. They will certainly be available I would think. You could try amazon. Not sure which country you're in, but if you have a local engineering institution or university it might be an idea to try the library. The books are pretty well known.
You could also try some of the oil industry...
In my experience no. The bolts have to be tight, obviously, but I have not come across a requirement for pretension.
Hope this helps. I'd be interested to see what others experience is.
Have a look at Ben Gerwick's book 'offshore Construction' or something like that. There ios another ref but it's slipped my mind. I'll come back later.
Hope this helps.
You might also try BS 2853 'Design & testing of steel overhead runway beams'. It's very old (1957 I think) but has not been withdrawn and is still in use so far as I am aware.
Hi Andyfabian. I think IRstuff and your boss are right. Let the kinetic energy be absorbed by strain energy in the cage structure. Better still if you treat the maximum possible velocity case as an extreme event, you can also take allowance for plastic deformation along with elastic strain...
Hi Kumar,
Yes you certainly started an interesting thread ! It looks even more like a glitch to me. The proportions of the structure are a bit unusual, but that shouldn't make any difference in the sort of eigenvalue analyses you're doing. I would suspect some kind of numerical problem in Algor...
Thanks Englishmuffin! That's a very interesting answer to my last question. I would certainly agree your example is a structure and I daresay you could devise some kind of structural/mechanical system with the same sort of behaviour at large deflections. The classic case is post- buckling of a...
The problem kumar posed was a radially compressed RING (presumbly linearly elastic). If the result from the analysis indicates an increased natural frequency what result would you expect if the radial loads were reversed to produce axial tension in the ring ? and what sort of result would you...
I don't go along with much of the above I have to say, but there again I'm not too old to learn !. If kumar is using some form of 'load stiffening' option it's basically a departure from a straightforward linear analysis and it will be only the axial load that makes any difference to the natural...
Hi Kumar,
It sounds like a glitch to me. Why don't you try putting the ring in radial tension and see what result you get. That will give an indication of what's going on.
Good luck.
Have a look at recent posts in the piping and fluid mechanics forum - there is some stuff on rudder design which should be applicable to your question. (It was in the wrong forum in the first place !)
Hope this helps.
