Mechanical Stresses Analysis of Thin Round Membranes in the Case of Large Deflections

An analysis of the methods for calculating the dependence of the deflection of multilayer round membranes on the applied overpressure was carried out. To compare theoretical calculations with experimental data, as an example, we considered a round membrane based on the structure Al/SiO2/Al with a total thickness of 2.5 μm. Using the COMSOL Multiphysics and ANSYS software packages, we calculated the stress distribution in the radial and tangential directions, the distribution of equivalent von Mises stresses over the membrane area, and also compared the obtained numerical values of mechanical stresses with the corresponding analytical estimates. We compared the deflection of the membrane depending on the applied overpressure obtained using software packages, analytical estimates and records obtained experimentally using an optical profilometer. It was shown that, when studying the deflection of membranes, which significantly exceeds the thickness of the membranes, to predict the deformations expected in the experiment, analytical relations obtained taking into account the presence of tensile forces, radial displacement, and elongation of the median plane should be used.