Simply supported?
Simply supported?
(OP)
Hello all,
I'm a 'mechanical', looking into the subject of 'structural' - wondering if it's worth expanding my horizons. Perhaps that's the first question, Is it worth it? Secondly, I'm doing some initial reading with the purposes of trying to move into the area of designing Mez Floor structures, and as far as I can gather that involves understanding and applying BS 5950, as a starter / minimum. Are there any texts or pointers out there that can illucidate the differences between the 3 basic approaches to beam (and consequent joint) design, which are simply supported, rigidly supported, and 'something else' inbetween...? I've navigated my way to portal frame design in an online reference and I'm starting to understand the sorts of approaches, but IMO the BS5950 does little to make itself understandable about the '3 basic approaches'. If it helps to steer me in an appropriate direction (either away from or toward 'structural'), my background is 14 years in engineering with an MSc, mainly in analytical disciplines, FEA, rotating machines, fatigue and some dynamics. Thank you, Charles Jenkinson
I'm a 'mechanical', looking into the subject of 'structural' - wondering if it's worth expanding my horizons. Perhaps that's the first question, Is it worth it? Secondly, I'm doing some initial reading with the purposes of trying to move into the area of designing Mez Floor structures, and as far as I can gather that involves understanding and applying BS 5950, as a starter / minimum. Are there any texts or pointers out there that can illucidate the differences between the 3 basic approaches to beam (and consequent joint) design, which are simply supported, rigidly supported, and 'something else' inbetween...? I've navigated my way to portal frame design in an online reference and I'm starting to understand the sorts of approaches, but IMO the BS5950 does little to make itself understandable about the '3 basic approaches'. If it helps to steer me in an appropriate direction (either away from or toward 'structural'), my background is 14 years in engineering with an MSc, mainly in analytical disciplines, FEA, rotating machines, fatigue and some dynamics. Thank you, Charles Jenkinson






RE: Simply supported?
Try looking at a book like "design of structural elements" by Chanakya Arya (i only refer you to that because i have a copy... there will be other similar titles by other authors!)
remember that 5950 is for structural steelwork which may be a sledgehammer to crack a nut depending on what the brief is.
Also, there's a whole load of stuff on the BCSA website, construction guidance, connections, and steelwork - all downloadable as pdfs
cheers and good luck, HM
No more things should be presumed to exist than are absolutely necessary - William of Occam
RE: Simply supported?
Beams are simply supported, which simplifies the beam element design. Columns are usually designed in accordance with Cl. 4.7.7. The colum effective lengths will depend on whether your system is braced or un-braced (this will depend on whether your client can accomodate vertical bracing in the area beneath the mezzanine). If the columns are unbraced then their effective length will be greater than 1.0 - some guidance is given in one of the Apendices to BS 5950. I dont have a copy of the code to hand at present, so can't give you the exact reference.
Obviously, if you are looking to move into more mainstream steelwork design, then there are a range of publications which will help - pretty much anything published by the SCI - but I always find the steel designers manual a good reference.
RE: Simply supported?
try these websites for some good basic principles and some background.
http://
http://www.bgstructuralengineering.com/
RE: Simply supported?
RE: Simply supported?
RE: Simply supported?
the way I see it is to always design for the worst case scenario. With pinned joints the isolated member forces will be greater. ex a simply supported beam has a bigger bending moment when it is not restrained at the ends.
the opposite is true for connections where the forces would be greater if it is fixed. And I usually design for a combination of the two, ex reduce the forces in the pinned beam somewhat and reduce the forces at the rigid connection. This is fairly easy and quick for small structures with lots of variables.
RE: Simply supported?
If you assume partial end fixity, you must design the columns for the resulting fixed end moment, which will usually increase the column size.
(In columns in simple construction, the dominant load effect is axial load, whilst in continuous construction the dominant effect is bending).
I take a view on the connection type, and design the members for the resulting forces accordingly.
RE: Simply supported?