Difference in Tendon profile from info tab and Tendon plot command

Question

I've modelled multiple tendons for a segmental bridge and I'm facing issues with the tendon profile. I've defined the tendon profile with coordinates with respect to the nodal axis and when I check the profile using the info tab the profile (in elevation) looks more or less all right; but when I plot the tendon using the PlTndGm command in stages, the tendon profile at the beginning of the tendon looks absurd. The screenshots are attached for your reference. 
 
 Is this is a glitch in RM or is there something I've not done correctly and am overlooking?

MarcosBeier · Answer

Hi Shijo, 
 For sure there is something in your input that leads to this odd path as the only possible solution for the Tendons with the created restraints. 
 
 From the plots, I could see extremely short Elements 120 and 142; so, the glitches are clearer near those elements. Although, if you check further. the same glitches of horizontal tendons are also happening for all other elements' beginnings and endings. So, they're probably related to the angles. Check the angle definitions at these regions as it seems the Tendons are too restrained. 
 
 At the Tendon geometry table input, I noticed you used alpha angles as always 0. This means the program will try to make all tendons at all points parallel to the nodes axis at all times. This could be ok for the straight lines, but it's probably not correct for the curved regions as the tendons will try to become perpendicular to all elements' start and end. When this is impossible it gives us a near solution, but this is wrong in geometry, at the tendons length, also in the forces, and mostly for the losses, as the path is incorrect. 
 
 I suggest you modify the vertical angles to "free", instead of "value" and "0", in the descending and uprising regions to allow for a smooth increase and decrease of the values of the angles at the model's beginning and end. Similar to the transitions in the plane. 
 There are some videos about Tendons input on our OpenBridge YouTube channel: 
 Modeling tendons in RM Bridge - YouTube 
 If you continue without being able to correct them, please file a Service Request and we could help get it right.