Pipeline bend calculation from strain gauge data

[Endriu]

Hi all,
I'm doing a stress analysis and I’m considering 3 buried pipelines carrying oil.

Vibrating wire strain gauges have been installed in different sections for a total of 468 strain gauges.

These have been arranged on the surface of the pipelines 120°apart:

This pipelines have suffered from a landslide. There has been a strain relief procedure accordingly. After that, the pipe has undergone another progressive landslide.



The data I surveyed by the strain gauges belong to the period that goes from august 2013 (start of the strain relief) to now.



Here attached an example :



(Data from a strain gauge during the strain relief procedure of the buried pipeline)

I need to compare the results I have from the finite elements stress analysis of the pipeline before and after the strain relief procedure, with the strain gauges’ data.





I’m looking for a software or a standard calculation method to get the stress [N/m^2] out of the strain gauge’s output data [microstrain].

Could you please help me out?


Thank you.

 

[Nidum]

Why can't you just use Young's Modulus ?

 

[Dr.D]

What is the orientation of the strain gages? Are they axial, circumferential, or something else?

 

[Endriu]

They measure axial strain.
I also need to compare the results of this measuring with the output of the Autopipe model. It gives stress, forces and moments in each point of the pipeline.