Body Load
Add a Body Load to domains for modeling general volumetric loads.
For loads caused by gravity or rotation, it is more convenient to use the Gravity and Rotating Frame nodes.
Shell Properties

Force
Select a Load typeForce per unit volume, Total force, or for 2D components, Force per unit area.
Then enter values or expressions for the components in the matrix based on the selection and the space dimension.
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.
For Total force, COMSOL Multiphysics divides the total force by the volume of the domains where the load is active. For 2D components, and if Force per unit area is selected, the body load as force per unit volume is then the value of F divided by the thickness.
Table 4-5:  
FV
FA
N/m2
Ftot
You can add the Phase subnode to specify the phase of this load in a frequency domain analysis.
Location in User Interface
Context Menus
Ribbon
Physics tab with Solid Mechanics or Multibody Dynamics selected:
Ribbon
Physics tab with Layered Shell or Membrane selected: