Discussion Forum

Hello,

Module: 3D, Solid Mechanics, Stationary

Situation description:

I would like to use COMSOL to simulate the soft microgripper behavior. The soft microgripper is placed in a vacuum environment and manipulated through the pressure difference. The microgripper is embedded with ten chambers covered with the membrane. (The structure is illustrated in the attachment figure below.)

In the beginning, the soft microgripper is under the atmospheric environment. When the outer pressure decreases, the inner chambers' pressure remains atmospheric (101300 Pa). Thus, the geometry asymmetry makes the membrane distend. The distended membrane creates tension at one side and compresses the other, forcing the structure to bend inward.

Boundary Load:

Inner chamber surface: 101300 Pa

Outer surface: Pn (Parameter sweep from 0 to 101300 Pa) (The load is illustrated in the attachment figure below.)

Problem:

When I mesh the geometry finer ( from normal to finer), the membrane deformation increase, when I mesh the geometry coarser, the membrane deformation decrease. Shouldn't it be the same deformation no matter what type of mesh level?

I was wondering why the simulation results turned out like this. Or are there any other methods to apply the air pressure load to simulate the vacuum variation in this situation?

Thanks!