Good evening, everyone!

I am just getting started with Abaqus. I had fun designing a pipe in three configurations available in Abaqus: top surface (d=406.4 mm), bottom surface (d=355.8 mm), and middle surface (d=381 mm) with a thickness of 25.4 mm. Strangely, I ended up with three different masses for the same pipe.

Only the mass from the middle surface configuration is equal to the one calculated manually.

But the question I'm asking myself is why the three configurations do not have the same mass when the final diameter and thickness are identical in all configurations.

Thank you in advance for your responses.