Surface Force Density in HFSS
HFSS can calculate surface force density for Work Bench coupling and for post processing within HFSS. The whole approach resembles Maxwell except that HFSS must calculate the surface force density at the post processing stage while solver provide the surface force density in Maxwell.
The surface force density formulation is provided in a technical note here. Surface forces may exist on surfaces where one side is conductor but the other is not, or finite conductivity and layered impedance boundary. The computation of surface force density will be performed at field geometry instance level.
This feature is mainly for the purpose of mapping surface force density in HFSS to Work Bench Mechanical. We will also provide it for post processing within HFSS. This feature should work regardless of HFSS solution types as long as surface forces exist. Surface forces may exist when one side is conductor but the other is not, or finite conductivity and layered impedance boundary.
If an old coupling project happens to request surface force and is solved again, then the surface forces (likely nonzero) will be passed to mechanical side.
Mapping surface force density from HFSS to Work Bench Mechanical
The behavior is the same as all current couplings.
- From the Mechanical side set up a surface force coupling to an HFSS design similar to Maxwell.
- Import the load.
Behind the scenes Mechanical will pass necessary information to HFSS, points on surface to request surface forces and auxiliary files, HFSS will then calculate the surface force densities and pass them back to Mechanical.
- Post process surface density within HFSS over any surfaces where surface forces exist.
Surface Force Density will appear in the context menu in the Other category under Fields menu.
In the fields calculator Surface Force Density
appears in the Named Expression list and the Quantity drop-down menu.
So the user can use it the same way as other vector quantities. 