Boundary Load

Use a to apply tractions or pressure to boundaries.


	This section is only present in the in the Layered Shell interface, where it is described in the documentation for the Boundary Load node.

Force

Select a — , , , or for 2D components, . Then enter values or expressions for the components in the matrix based on the selection and the space dimension.

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For , the traction components are given explicitly.

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For , COMSOL Multiphysics then divides the total force by the area of the boundaries where the load is active. Then it is applied in the same way as for a . When working with curved boundaries or local coordinate systems, use this option carefully, as the result is not always intuitive.

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For , a scalar input is given, and the orientation of the load is given by the normal to the boundary. The pressure is positive when directed toward the solid. In a geometrically nonlinear analysis, the current surface normal and area are used.


	After selecting a Load type, 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.


Load Type	variable	SI unit	Geometric Entity Level	Space Dimension (components)
Force per unit area	FA	N/m2	boundaries	3D (x, y, z) 2D (x, y) 2D axisymmetric (r, z)
Force per unit length	FL	N/m	boundaries	2D (x, y)
Total force	Ftot	N	boundaries	3D (x, y, z) 2D (x, y) 2D axisymmetric (r, z)
Pressure	p	Pa	boundaries	3D (x, y, z) 2D (x, y) 2D axisymmetric (r, z)

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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

Ribbon

Physics tab with or selected:

Physics tab with selected: