Tendon Profile Equations 2

[slickdeals]

Is there a generic formula to generate the profile of post-tensioning tendons, which includes the parabola (low points) and reverse parabola (high points).

I am trying to generate a worksheet to compute the shear capacity of prestressed concrete beams. Equations require me to calculate the depth of tendons, decompressing moment etc. based on AS3600 or BS8110 formulae.

 

[rapt]

Slickdeals,

No, there is not a generic formula.

You can either do the math to create a parabola with reverse curves and all of the possible permutations of end conditions like I did for RAPT.

Or use a good product (like RAPT) that has already done it for you (as well as the calculations for shear capacity of prestressed beams to AS, BS, ACI, Indian and Eurocodes!).

 

[ishvaaag]

Again some Mathcad 2000 Professional worksheets that should deal effectively with the matter.

I may produce pdf printouts for inspection but none as effective for production as the actual operative worksheets here posted.

I remember that ACI sold one book that had one old MSWORKS worksheet dealing with this matter as well.

 

[ishvaaag]

...It was for MSWORKS for DOS, not even MSWORKS for windows managed to open normally the file (maybe with trickeries etc or importing to EXCEL)

It was one from FAGUNDO, try to contact the author.

http://trid.trb.org/view.aspx?id=351813

 

[slickdeals]

Ishvaaag,
Thank you much. Do you happen to have the references on which your worksheets are based?

 

[ishvaaag]

If I don't quote normally it is just work I did myself on the parabola equations, and imparted equivalent forces (quite likely if in doubt for these I looked somewhere, PTI Handbook probably). I only had seen by then the Fagundo worksheet and article in the ACI book and thought seeing the tendon centerlines as charts in Mathcad would be both rewarding and allowing for speedier check of the work. I was also learning Mathcad, used defined functions for something that Mathcad could more or less directly provide, but anyway, I think it worked.