Physics Symbols
There are physics symbols available with structural mechanics and some other physics features to help you to graphically indicate boundary conditions, loads, and other physics features:
Physics Symbols for Structural Mechanics and Other Physics
To display the physics symbols listed in Table 3-5, select the Enable physics symbols check box under Physics Symbols in the main physics interface node’s Settings window. This check box is not selected by default.
Once you have turned on the physics symbols for a certain physics interface, you can fine-tune the display. Every feature that has associated physics symbols now has a Show physics symbols check box, by which you can control the display of the symbols for that specific feature.
In the Physics Symbols section in the settings for the physics interface, you can click the Select All button, which displays all symbols in that physics interface by selecting all Show physics symbols check boxes in the Settings windows for the physics features that include symbols. Similarly, the Clear All button clears all Show physics symbols check boxes in the individual physics features.
The following symbols are available with the applicable structural mechanics feature nodes and with some other physics interfaces (this table is a partial list of available symbols).
Table 3-5: Physics Symbols
1 Requires the Structural Mechanics Module
2 Requires the MEMS Module
About Coordinate Systems and Physics Symbols
Physics symbols connected to a node for which input can be given in different coordinate systems are shown together with a coordinate system symbol. This symbol is either a triad or a single arrow. The triad is shown if data are to be entered using vector components, as for a force. The single arrow is displayed when a scalar value, having an implied direction, is given. An example of the latter case is a pressure.
In both cases, the coordinate directions describe the direction in which a positive value acts. The coordinate direction symbols do not change with the values actually entered for the data.
Physics symbols are in most cases displayed even if no data values have been entered in the node.
In some cases, a single feature can display more than one symbol. An example is the Point Load node in the Beam interface, which can display either the Point Force symbol (), the Point Moment symbol (), or both, depending on the data entered. In those cases, no symbol is shown until nonzero data is entered.
Displaying Physics Symbols in the Graphics Window — An Example
1
Add a physics interface, for example, Solid Mechanics, from the Structural Mechanics branch.
2
In the Solid Mechanics node’s Settings window, under Physics Symbols, select the Enable physics symbols check box and then click the Select All button.
3
Add any of the feature nodes listed in Table 3-5 to the physics interface. Availability is based on license and physics interface.
4
When adding the boundary, edge, or point (a geometric entity) to the Selection list in the feature Settings window, the symbol displays in the Graphics window. See Figure 3-10 and Figure 3-11.
Figure 3-10: Example of Boundary Load physics symbols as displayed in the COMSOL Multiphysics model “Deformation of a Feeder Clamp”.
Figure 3-11: Example of Roller and Boundary Load physics symbols as displayed in the COMSOL Multiphysics model “Tapered Cantilever”.