My situation in detail is that there is a cylinder on the slightly vibrating table. The cylinder deforms due to two forces, which is gravity and force from table. I want to get the information of deformed area of the cylinder. Since the force from the table has certain frequency spectrum, I want to study the effect of table force frequency on the cylider.
The question in detail: I want to get the deformed area when I do the frequency domain study. When I study stationary, it is easy to get deformed area referring to https://www.comsol.com/forum/thread/206041/deformed-surface-area-calculation, but frequency study always gives me undeformed area. Thanks to Henrik Sönnerlind, COMSOL employee, I get to know that frequency domain study is linear so it is normal to obtain undeformed area. Then he advise to do like this:
"To compute the area for a linear (or linearized) study, you must resort to expressions that make use of the displacement explicitly. One way of doing that is to use Stokes' theorem, and convert the area integral of '1' into a line integral of something containing the coordinates. The current area can be then be computed by adding the displacements to the coordinates"
Nevertheless, due to my poor understanding, I cannot catch the way. So can anyone explain it more in detail? I really hope to solve this problem with COMSOL.
Thank you