FEM ConstraintPressure

Description

Applies a pressure load to a face (introduced in 1.1: or edge in 2D models).

Usage

1. There are several ways to invoke the command:
   • Press the Pressure Load button.
   • Select the Model → Mechanical Boundary Conditions and Loads → Pressure Load option from the menu.
2. Press the Add button and select face(s) (introduced in 1.1: or edge(s) in 2D models) in the 3D View. Optionally press the Remove and click on the faces/edges that you want to remove from the selection.
3. Edit the appropriate window to specify the pressure load in MPa.
4. Tick the box to reverse the direction if necessary.

Pressure load applied to a cylinder

Properties

• DataEnable Amplitude - introduced in 1.1: Enables the use of CalculiX's amplitude for the time variation of the pressure load. At a given time, magnitude of the load is multiplied by the amplitude value corresponding to that time. Linear interpolation is used between the specified values. Constant values are used outside of the specified range.
• DataAmplitude Values - introduced in 1.1: Amplitude table in the following format:

time_1, amplitude_value_1
…

Default is linear increase from 0% at t=0 to 100% at t=1:

0, 0
1, 1

Notes

• Distribution of the pressure on a face is always uniform and always perpendicular to the face.

• 0.21 and below: Pressure load can be applied to shells but only when Gmsh is used for meshing and group meshing is set to true. It is hardcoded as true so the user doesn't have to worry about that. However, due to a bug, pressure load may require remeshing to work on shells.
• This feature uses the *DLOAD card in CalculiX.