Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Moment Frame Algorithms??

[Subject Prev][Subject Next][Thread Prev][Thread Next]
In a message dated 8/20/99 20:40:19 Eastern Daylight Time, 
Bill(--nospam--at)AllenDesigns.com writes:

> I intend this spreadsheet to design the connections,
>  pad footings and grade beam in one operation.
>  

Bill is onto something good here.  One suggestion in lieu of moment 
distribution would be to use the stiffness method.  If you have a single bay 
single story frame with fixed column bases you only need to set up a solution 
to a six equations and six unknowns; (bases hinged it expands to 8x8).  It 
would also lend itself well to a sloping beam and/or foundations at different 
elevations.  The result would give you all the member end forces so you could 
finish it off with calcs for your favorite connections.

I'm looking at some homework assignments from my master's program where we 
went through a single bay structure with x bracing for various loading and 
support conditions. (Joint loads, distributed loads, Hinged joints, moment 
connected joints, support settled, etc.)  Without the cross bracing the 
matrix would be pretty sparse.  I did all the matrix construction and 
manipulation with VP-Planner (1989).  I also found some disks but they are 
5-1/4" and here at the office there aren't any 5-1/4 drives!!  Have to check 
them at the house.

Bill's on the right track with a homegrown solution to problem that you need 
to solve often.  Commercial software can be a great help but sometimes it 
doesn't get you all the way through the design process in the manner you'd 
like.  You end up working in fits and starts, trying to plug results from 
analysis software into design details.  Your own solution can be as seamless 
as you want to it to be, if you're willing to invest the time and effort.

Jan Harris, PE
Liberty Engineering, PC
Virginia Beach, VA