Stress Lines for a curved object

Hi Guys,

Im trying to do a stress line analysis on a curved object. Im fairly new to the plugins that do this such as karamba and finding it quite difficult to understand the inputs that go into it. 

Ive attached the rhino file for the piece that I want to test it on. If anyone could help me with some examples or suggestions of how I could do this. I would be very grateful!

Thank You!