Abaqus - Stent Modeling with SMAs-unusual unloading behaviour

Dear Abaqus Experts,

I have been trying to model the stent behavior during loading and unloading (crimping and expansion). However, the device structure does not spring back to its initial configuration and it shows unusual behavior during unloading with increased kinetic energy and oscilations. I tried to use Rayleigh damping for the material properties, but it did not help.

The material is entirely in the elastic region (Austenite and Martensite) throughout all steps (PEEQ=0). I also checked the material properties in a seperate model and it is correct. 

Image1: e-s diagram for a selected element 

image2: energy balance during crimping (0-0.3), expansion (0.3-0.6) and recoil (0.6-0.9)

Thank you for your help and advice in advance.