# Volume change of a deformable cylinder with a uniform spinning angular velocity

Consider a deformable cylinder without gravity with a uniform spinning angular velocity and the cylinder is not in contact with anything. In theory this cylinder shouldn't change its cross sectional area or volume as it spins with a uniform angular velocity. But in finite element simulation is it possible for the volume or cross section area to change in time as it spins around its own central axis?

• There are many details involved in different time discretization techniques, but I think that, in general, you cannot expect the kinetic energy to be conserved exactly. Some time discretization methods may do it better than the others.
– knl
Apr 14 at 8:20
• the change in the volume or cross section area is so big when time goes big that I'm not sure if it's due to numerics at all Apr 14 at 9:55
• I have no idea why you say the CS area and volume should not change. The cylinder is acted on by a body force due to centripetal acceleration. Apr 14 at 17:36
• I think he is meaning that starting from rest, after certain time, an equilibrium is reached after which there is no change in the volume assuming the angular velocity stays constant.
– knl
Apr 14 at 19:31
• Yes, that is case I am assuming, also. There is a closed form solution for this steady-state case that is presented in many theory of elasticity texts. The cylinder expands radially due to the centripetal acceleration. Apr 14 at 19:45