Simulation of moving wheel on the rail?

Hi Guys,

I am new to abaqus and i want to simulate moving wheel on the rail track. I have set let say a step time =1 sec and the boudary condition for wheel is at t=0, it is at x=0 and at t=1 is is at x=2 but the wheel is not moving. Instead of that, it is tilting is other direction. It may happen because i have imposed tie constrained between wheels and rail surface but  i changed it to surface to surface contact and it still didn't work and the job gave errors. I have also given contraint of coupling between centre of wheel and the surface of wheel. I have attached the image of model. I want to know where i went wrong. 

Thanks,

Kshitij Gaikar