Pranshu Kharbanda

Thanks for the input. Okay, so I have did that and the solution converged. 

The top block only moves by 0.67 mm max and doesn't fly off. I suppose this is because of the short time duration of 1 to 1.1 s. Is there any way to double check the force at which sliding starts.

Since this simulation takes long time , may I ask if usually we need to specify this small increment of load steps for frictional contact? Is it the sliding behavior that is causing this highly nonlinear phenomenon. As I would have to move on to more complex tasks based on my understanding for this. Thanks again.