Thank you for your suggestion, Sir.
I have done as you said and the model ran smoothly. However, i have ran into an issue when probing stress and acceleration in the solution. I created 4 coordinates (2 on the outer surface and 2 on the inner surface of the tube), and i assigned those coordinates to the probes accordingly. However, while the probes on the outer surface displayed results, the inner probes do not seem to be generating results. i tried several times to update the solution, but to no avail. I attached a screenshot to show the positions of the coordinates and the solution section. As you can see CTP and CTP_2 probes are showing results while CSP and CSP_2 are not.