Prescribed Acceleration
The Prescribed Acceleration node adds an edge, boundary, or domain condition where the translational or rotational acceleration is prescribed in one or more directions. The prescribed acceleration condition is applicable for Time Dependent and Frequency Domain studies. With this condition it is possible to prescribe an acceleration in one direction, leaving the shell free in the other directions.
The Prescribed Acceleration node is a constraint, and overrides any other constraint on the same selection.
Coordinate System Selection
Specify the coordinate system to use for specifying the prescribed acceleration. The coordinate system selection is based on the geometric entity level.
Domains (Plate interface)
From the Coordinate system list select from:
Boundaries (Shell and Plate interfaces)
From the Coordinate system list select from:
Boundary System (a predefined normal-tangential coordinate system)
Edges (Shell interface)
From the Coordinate system list select from:
Global coordinate system (the standard global coordinate system).
Local edge system (the default)
Face Defining the Local Orientations
This setting is used in conjunction with a Local edge system and Shell Local System. If the acceleration 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.
Prescribed Acceleration
To define a prescribed acceleration for each spatial direction (x, y, and z), select one or more of the Prescribed in x direction, Prescribed in y direction, and Prescribed in z direction check boxes. Then enter a value or expression for the prescribed acceleration components ax, ay, and az.
Prescribed Angular Acceleration
To define a prescribed angular acceleration for each spatial direction (x, y, and z), select one or all of the Prescribed around x, y, and z direction check boxes and enter a value or expression for in each , , or field.
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.
Prescribed Acceleration can not be used as a weak constraint.
Location in User Interface
Context Menus
Shell>Face Constraints>Prescribed Acceleration
Shell>More Constraints>Prescribed Acceleration (Edge)
Plate>Face Constraints>Prescribed Acceleration
Plate>More Constraints>Prescribed Acceleration (Boundary)
Ribbon
Physics tab with Shell selected:
Boundaries>Face Constraints>Prescribed Acceleration
Edges>>More Constraints>Prescribed Acceleration
Physics tab with Plate selected:
Domains>Face Constraints>Prescribed Acceleration
Boundaries>>More Constraints>Prescribed Acceleration