COMSOL 6.2 - Prescribed Acceleration

Prescribed Acceleration

The node adds a boundary or domain condition where the acceleration is prescribed in one or more directions. The prescribed acceleration condition is applicable for Time Dependent and Frequency Domain studies. With this boundary condition it is possible to prescribe an acceleration in one direction, leaving the beam free in the other directions.

The Prescribed Acceleration node is a constraint, and overrides any other constraint on the same selection.


	For details about prescribed velocities and accelerations, see Prescribed Displacements, Velocities, and Accelerations.

Coordinate System Selection


	Coordinate systems with directions that change with time should not be used.

Specify the coordinate system to use for specifying the prescribed translational/rotational acceleration. See the section for Edge Load. Depending on the selected coordinate system, the acceleration components change accordingly.

Prescribed Acceleration

Select one or all of the , , and for 3D models, check boxes. Then enter a value or expression for ax, ay, and for 3D models, az.

Prescribed Angular Acceleration


	For 2D models, to define a prescribed angular acceleration select the Prescribed in out of plane direction check box and enter a value or expression for ∂2θ0z/∂t2.


	For 3D models, to define a prescribed angular acceleration for each space direction (x, y, and z), select one or all of the Prescribed around x direction, Prescribed around y direction, and Prescribed around z direction check boxes and enter a value or expression for in each 2θ0x/∂t2, 2θ0y/∂t2, or 2θ0z/∂t2 field.

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You can add a Harmonic Perturbation subnode for specifying a harmonic variation of the values of the prescribed acceleration in a frequency domain analysis of perturbation type.

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cannot be used as a weak constraint.

Location in User Interface

Context Menus

Ribbon

Physics tab with selected:

Context Menus

Ribbon

Physics tab with or selected: