Evaluation of Volumteric displacement

Hi all,

I am modelling a diaphragm deformed under pressure loading in an axisymetric model.

I was wondeing if there is a way to evaluate volumetric displacemnt of the diaphrgam due to displacement.

Currently I have considered taking the avegage vertical diaplacemnt of the diaphragm across its length and then multiplying by area to give an effective displacement.

Is there a direct way of evaluating this in COMSOL?

Possibly by evaluating the intergral of area beneath the diaphrgam and an arbitary line?

Thanks,
Matt