1) I would like to check all the friction force at each node where the contact occurs with time and calculate the sum of the absolute value of friction force. Does anybody know how to do that?

2) What is the reason why the equilibrium doesn't satisfy for all time? I am using Implicit Method.

Let's say there are a rigid pipe and a linear elastic hose. The gravity effect is considered. The hose is located inside the pipe. The Pipe is fixed. The bottom surface of the hose is also fixed. Axial impressive force is applied on the top surface of the hose. Then it will be helically buckled.

The equilibrium in the axial direction will be

Weight + Applied force - Transmitted force at bottom surface - friction force. = 0.

The problem is the above equilibrium equation doesn't satisfy for all time. I think that is because it is not static but dynamic. (Please correct me if I am wrong)

I use RCFORC to calculate friction force. It says the RCFORC uses average value for all friction forces. (Please correct me if I am wrong). Which means there is a chance that the positive and negative friction values are canceled out.