Ring Load
A load applied to a point, not located at the axis of revolution, in a 2D axisymmetric model actually represents a ring load. Add a Ring Load to points located at R > 0 to model such loads.
Coordinate System Selection
The Global coordinate system is selected by default. The Coordinate system list contains all applicable coordinate systems in the model. Prescribed loads are specified along the axes of this coordinate system. See Coordinate Systems and in the COMSOL Multiphysics Reference Manual.
Face Defining the Local Orientations
This section is not shown if the Global coordinate system is chosen in the Coordinate System Selection. If the load is prescribed for an edge which is shared between boundaries, the edge system can be ambiguous. Select the boundary which should define the edge system. The default is Use face with lowest number.
Force
Select the Load type — Force per reference area, Force per deformed area, Force per reference length, Force per deformed length, or Total force. Enter values or expressions for fA, fa, fL, fl, or Ftot.
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The Load list normally only contains User defined. When combining with another physics interface that can provide this type of load, it is also possible to choose a predefined load from this list.
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The Total force option should not be directly interpreted as a resultant, since the orientation is changing. Rather, it should be interpreted as the per reference length values, multiplied by 2πr, where r is the radius of the point.
Linear Buckling
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog.
If you are performing a linear buckling analysis with a combination of live and dead loads, select the Treat as dead load checkbox to indicate that the load contributions from this node are constant. The default is that a load is proportional to the load factor.
For more information about live and dead loads, see Buckling Analysis.
 
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You can add the Phase subnode to specify the phase of this load in a frequency domain analysis.
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You can specify this load to be a Harmonic Perturbation in a frequency domain analysis.
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You can assign this load to a load group. See Load Cases in the Structural Mechanics Modeling chapter.
Location in User Interface
Context Menus
Membrane > Ring Load
Ribbon
Physics tab with Membrane selected:
Points > Membrane > Ring Load