Tendon Losses

Question:

Hello, I am wondering why the tendon losses are the same for every tendon in this bridge. (model attached)

 

The bridge is on a horizontal curve and each tendon is offset from centerline a different amount therefore each tendon should be different lengths. Different length tendons should have different losses but when going to result tables>tendon>tendon approximate loss, I see that the losses are the same for each tendon. Why is this?

 

When creating the tendons, I used the copy feature and checked the box that auto adjusts for length.


Thanks

Answer:

Hello,

When working with curved PSC structures, it wouldn't be right to use Element as reference axis for the tendon.

When element is used as reference, the reference is taken as element local x axis.  This is always straight for each element.  Hence, the effect of change in the angle and thus the loss due to curvature in geometry of structure is lost.
To avoid this, the Straight option should be used as reference and the actual global coordinates of tendons have to be entered.  With this done, the tendon loss would be as expected.
Kindly let us know if further assistance would be required.

Regards,
Nandeep
Technical Manager, MIDAS
Creation date: 10/17/2018 11:04 PM (dklee@midasit.com)      Updated: 10/18/2018 8:34 AM (dklee@midasit.com)
Files   
DataImage44.png
Roden Crater PT - New Tendons2.mcb