Acoustics and vibro-acoustics > Simcenter Nastran FEM acoustics > FEM Adaptive Order (FEMAO)
Solution stabilization options
You can apply solution stabilization at element Gauss points to correct high-frequency dispersion in standard FEM and FEM Adaptive Order (FEMAO) acoustic and vibro-acoustic solutions.
In acoustic and vibro-acoustic solutions, you mesh the acoustic domain with finite elements whose size is typically based on a fraction of the minimum wavelength of the solution. At higher frequencies, the mesh size may introduce high-frequency dispersion into the results. To reduce dispersion as the solution frequency increases, the finite element formulation incorporates a stabilization algorithm applied to the Gauss points.
In a standard FEM acoustic or vibro-acoustic solution, use the STABFEM option to reduce dispersion for linear acoustic elements.
In a FEMAO acoustic or vibro-acoustic solution, use the STABAO option to reduce dispersion for linear acoustic elements and pseudo-parabolic elements (that is, geometrically parabolic elements that are linear because the mid-nodes on an edge or face are aligned with the vertex nodes).
Correction of dispersion errors with stabilization applied
For more information about FEMAO solutions, see Finite Element Method Adaptive Order (FEMAO) solutions.
Where do I find it?
FEM stabilization
| Application | Pre/Post |
|---|---|
| Prerequisites | A Simulation file as the work part and displayed partSimcenter Nastran as the specified solverAcoustic or Vibro-Acoustic as the specified analysis typeOne of the following as the specified solution type:SOL 108 Acoustic Transfer VectorSOL 108 Direct Frequency ResponseSOL 108 Direct Frequency Response FunctionsSOL 111 Modal Frequency ResponseSOL 111 Modal Frequency Response Functions |
| Simulation Navigator | Right-click an active acoustic or vibro-acoustic solution→Edit |
| Location in dialog box | Solution type that supports FEMAO: Solution dialog box→Bulk Data page→Enable Adaptive Order for Acoustic Elements →FEM Stabilization (STABFEM) set to YES****Acoustic as the specified analysis type and SOL 108 Acoustic Transfer Vector or SOL 111 Modal Frequency Response as the specified solution type: Solution dialog box→Bulk Data page→FEM Stabilization (STABFEM) set to YESNote: Simcenter Nastran Acoustic SOL 108 Acoustic Transfer Vector and SOL 111 Modal Frequency Response do not support FEMAO, so the Enable Adaptive Order for Acoustic Elements option is not available. You can apply stabilization to a FEM solution directly. |
FEMAO stabilization
| Application | Pre/Post |
|---|---|
| Prerequisites | A Simulation file as the work part and displayed partSimcenter Nastran as the specified solverAcoustic or Vibro-Acoustic as the specified analysis typeOne of the following as the specified solution type:SOL 108 Direct Frequency ResponseSOL 108 Direct Frequency Response FunctionsSOL 111 Modal Frequency Response****SOL 111 Modal Frequency Response Functions |
| Simulation Navigator | Right-click an active acoustic or vibro-acoustic solution→Edit |
| Location in dialog box | Solution dialog box→Bulk Data page→Enable Adaptive Order for Acoustic Elements →FEMAO Stabilization (STABAO) set to YESNote: Simcenter Nastran Acoustic SOL 111 Modal Frequency Response does not support FEMAO, so the Enable Adaptive Order for Acoustic Elements option is not available. |
Learn more
Finite Element Method Adaptive Order (FEMAO) solutions
FEMAO convected flow workflow
Steady state fluid velocity in an acoustic solution workflow
Using viscoelastic materials in FEMAO solutions
Quick links
Command reference
Pre/Post video examples
Bulk Entry Descriptions
Simcenter 3D tutorials
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Solution stabilization options, Simcenter 3D 2021.1 Series
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Source: https://docs.sw.siemens.com/en-US/doc/289054037/PL20200601120302950.advanced/xid1926859_v1 · retrieved 2026-07-17