Truss
Truss
(OP)
hi guys,
kindly find attached a sketch which shows a eccentric truss with knee bracing for the column. This is designed for the huge lateral forces from the wind load.kindly put your reviews for the attached design.
kindly find attached a sketch which shows a eccentric truss with knee bracing for the column. This is designed for the huge lateral forces from the wind load.kindly put your reviews for the attached design.






RE: Truss
Besides, that's not quite the way the forums are intended to work. To ask for a blanket review of a design will probably get you no constructive answers. No one has the time to review your design for adequacy or even comment unless you ask specific questions. This is not a free engineering review service. In order to review a design, all of your assumptions have to be laid out, all of your design parameters would have to be given, your location and code would have to be given, and material specifications provided. That's way too much to expect from a forum.
Please re-state your issue with specific questions that you might have. Give your location and code. Perhaps then you will get some beneficial response.
RE: Truss
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Truss
Mike Halloran
Pembroke Pines, FL, USA
RE: Truss
truss has a specific geometry to withstand loading's, so i just asked your opinion. Sharing ideas and opinions is what this forum is about , correct ?
Please find attached the truss design , This is originally modeled in SAP 2000 v 15 ultimate , this is a roof canopy structure, 115 meters x 90 m . there is a huge lateral load for wind . Any details will be provided.
Thanks
Alex
RE: Truss
RE: Truss
RE: Truss
RE: Truss
From just looking at the proportions or the diagram the knee brace looks small. But it might be large enough to do so weird things to the column. And strictly speaking, since the horizontal chords are carrying moment near the columns that isn't actually a truss but is, rather, a frame. I think the distinction is important since, as shown, there will likely be some large moments transferred around and through the truss/column interaction as well including in that horizontal bottom chord adjoining the column. Also, it is worth asking whether that knee brace will provide enough lateral stability to the system.
Without knowing anything about the system other than what's shown on the sketch I would suggest you consider whether it would be better to design the trusses as pure trusses, pin them to the columns, and provide the lateral stability to the system through something that is more robust than just those braces (i.e. full frame bracing, shear walls, etc.) That is simply my opinion based on a limited understanding of the situation and actual condition may vary significantly, of course. In other words, that's just my two cents (rubles, lira, rupees, etc.) worth.
RE: Truss
Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.
RE: Truss
This is not the case here, and I would hardly call this a knee braced condition.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Truss
If the columns are continuous from ground to the top chord, knee braces would not be required and the structure would be capable of resisting substantial wind load without knee braces. If the columns are terminated at the bottom chord, the structure has negligible resistance to lateral load and is not helped much by knee braces.
BA
RE: Truss
You could also eliminate the knee braces by embedding the columns and creating a fixed condition at the base of the columns.
RE: Truss
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Truss
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Truss
BA
RE: Truss
You are correct. I would not call it a knee brace either, but it, in effect, it is helping the top and bottom chords of the truss to create the same resisting moment to help the column and structure laterally.
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com