Damping and Losses
For frequency domain (eigenfrequency or frequency domain studies) and transient simulations it is often necessary to include damping in the model. This is particularly important for resonant MEMS devices.
Within COMSOL Multiphysics, damping can be modeled explicitly by coupling the relevant physics interfaces into the model. Examples of such couplings include:
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Modeling the movement of the structure through a fluid directly by means of a complete fluid-structure interaction model. This can be done using the Fluid-Structure Interaction interface.
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Modeling thin films of a fluid using The Thin-Film Flow Interfaces (in the CFD Module User’s Guide), or by means of the thin film damping boundary condition, integrated into the structural mechanics physics interfaces.
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Modeling thermoelastic damping explicitly by including heat transfer and the relevant thermodynamics in the model. See The Thermoelasticity Interface.
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Modeling acoustic losses through anchor structures in the frequency domain using a perfectly matched layer.
Infinite Elements, Perfectly Matched Layers, and Absorbing Layers in the COMSOL Multiphysics Reference Manual
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Modeling losses through anchor structures in the time domain using a spring damper system.
In the Structural Mechanics Module User’s Guide
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The Fluid–Solid Interaction Interface
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Mechanical Damping and Losses
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Springs and Dampers