Modelling parafil guys in microstran

Hi,

I'm trying to model Parafil in Microstran (see screenshot below). 

I've used the following material properties from the datasheet:

E = 9800 kN/sqm

Density = 0.955 t/***

PR = 0 (not sure what to use for parafil)

Alpha = 1.175e-005

I've used the CABLE member type (as I would in MS Tower) but I don't know how what unrestrained length (Lo) to input to show the pre-tension in the member.

Also, can you please advise if you see any issues with the member of material properties?

Cheers,

Josh Kidd