Boundary Load

Use a to apply tractions or pressure to boundaries.

Select a — (the default), , , 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 body load as force per unit volume is then the value of F divided by the thickness.

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For , COMSOL Multiphysics then divides the total force by the area of the surfaces where the load is active.

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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 load current surface normal is 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: