# Prestressed calculated force

Hello,
I just have a question here

I am asking in the first screenshot, How sofistik get the force “4431.3 KN” which is in the middle with red ??

As The maximum permissible force is just 1177 KN as in the second screenshot

4 Tendons in group => 4431.4/4=1107.8 kN/tendon

just 2 last things. Then what is the difference between nominal/external force(Po) and the maximum permissible force (Po,max) ? Also how can I input the value of Po,max and don’t let SOFiSTiK calculate it based on the code?

Thank you

• Nominal/external force (P0) = Reference force:
Whatever is specified under `SYSP ... ZV ...`, i.e. in your case: `SYSP 2 ZV 1243`
• Po,max = Maximum force when tensioning, i.e. how hard you may pull the cable
• Pmo = Maximum force after tensioning, i.e. how much force/stress you are allowed after the tensioning (since there’s usually some slip/friction by the anchor during the wedging)

One possible solution:

• Specify a reference force (`SYSP ... ZV ...`)
• Specify your max forces (during/after tensioning/slip/…) with `PFAC FAC ... FACA ...`

If you chose your max tendon force during stressing as 1243 kN and you allow higher stressing during the tensioning (e.g. 10% more):
`SYSP 2 ZV 1243`
`PFAC FAC 1.0 FACA 1.1`

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Thank you for this clarification

I just want to know were i can write the lines that you wrote ? as i now know the values just need to make them as an input.

Thank you

Sorry, but the input I gave you is for working with teddy (text input).
I’m not really familiar with the graphical interface.

Then can you show me how to make it in teddy ? or if i am working with graphical interface this will be not possible?

Thank you

The point is that I’m not familiar with the graphic interface. Look through the training videos/tutorials in that case.

If you want to do it in teddy check out the examples in your installation folder, e.g.:
C:\Program Files\SOFiSTiK\2022\SOFiSTiK 2022\tendon.dat\english\tendon1.dat
or the others in that folder.

Just replace the `PSIG` line with the `PFAC` command I wrote previously.

Be aware that teddy has a steep learning curve.

Thank you for you reply

I know that teddy is not that easy but i just want to solve this problem with it as i also asked here about how to reach the same goal with graphical interface but No one answers me.

Just one last thing. Do i have to replace`PSIG` line just with this
`PFAC FAC 1.0 FACA 1.1` ? or with that
`SYSP 2 ZV 1243`
`PFAC FAC 1.0 FACA 1.1` ?

Tank you

Just replace it with the `PFAC` line.
The `SYSP` command is usually in the beginning of the tendon program, you’ll have to input the correct force/friction values there.

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In the PT Editor in SOFiPLUS you can find the definition for PFAC with the option

“Prestressing - With Factors”

Hello

i just have a problem as when i open tendon.dat and start to change in it as you mentioned it tells me when i save the file that access denied and i am not allowed to change what is written

You have to save it somewhere else than your `C:/Program Files/` folder