PM interaction diagram (concrete)
PM interaction diagram (concrete)
(OP)
When checking a flexure and axial member, how to find out the safety of the member?
Often drawing PM interaction diagram ?
Or simply checking the equation of the safety ?
When you draw the PM interaction diagram , using the software or spread sheet ?
And tell me the software's name ( commercial or free)
Often drawing PM interaction diagram ?
Or simply checking the equation of the safety ?
When you draw the PM interaction diagram , using the software or spread sheet ?
And tell me the software's name ( commercial or free)






RE: PM interaction diagram (concrete)
I calculate the max P value allowed and then draw a series of lines through these 4 points. This is my interaction diagram. I then check loading conditions against this interaction diagram and hopefully all points fall within.
If not, then I change the bar arrangement. The spreadsheet then calculates maximum stirrup spacing and my standard details take care of the tie arrangement and spacing at the top and bottom. If shear is an issue, I do it by hand; I haven't had a chance to modify the spreadsheet to do this.
RE: PM interaction diagram (concrete)
RE: PM interaction diagram (concrete)
Pure Axial Load, Decompression (where one face has 0 strain), Balanced Point (compression controlled point), Tension Controlled Point, and Pure Moment.
It is important to note that the phi factor will be the same for moment and axial depending on the strain in the steel.
RE: PM interaction diagram (concrete)
StructuralEIT, I believe this is what you meant, but it wasn't clear to me: at any given P,M point on the curve, there is only one phi factor which will be applied to both axial and flexural capacity, and which depends entirely on the strain in the extreme layer of steel (this is correct)
RE: PM interaction diagram (concrete)
RE: PM interaction diagram (concrete)
http://www.ce-ref.com/short_col.htm
http://www.strunet.com/concrete_column/ccol03.html
RE: PM interaction diagram (concrete)
RE: PM interaction diagram (concrete)
http://www.dot.state.fl.us/Structures/proglib.htm
RE: PM interaction diagram (concrete)