Discussion Forum

I am simulating the parallel-plate capacitive sensor, with upper electrode as flexible diaphragm and bottom one mechanically fixed as another electrode. In Solid Mechanics, I constrained edge of diaphragm and applied pressure to see the output deflection over pressure, that's something really simple. In Electromechanics, I chose the same material, Linear Elastic Material and Solver setting for diaphragm, adding a air gap as dielectric material without any mechanical properties, and defined electrical terminals for both topper and bottom eletrodes, to see the output deflection over pressure and its corresponding capacitance change . After simulation, the deflection results from Solid Mechanics and Electromechanics are different, up to 30%. The solid Mechanics gives the value the same to theoretical calculation with linear output, but that from Electromecahnics shows nonlinear deflection. When I chose the Linear Elastic Material as "imcompressive" and "linear strain over stress" in Electromechanics, it gives closer results to that in Solid Mechanics, but I didn't chose these two options in Solid Mechanics.

So I wonder if it is a bug there.