Hi all,

I am trying to do optimisation on indentation for a number of tests. For a few of them it runs perfectly fine and I got the coefficients for viscoelastic material, however for the others I have two main problems with the optimisation process.

The first one is FATAL ERROR, which for some initial values, I got this error, but even for the other initial values which the program runs, the optimisation process doesnt do anything really. It always gives back the initial values as optimised parameters after a number of itterations. Is there any way to improve this process?

Many thanks,