Applying a time-dependent boundary condition

Estimated time to complete: 5–15 minutes

In this tutorial, you will create a time-dependent enforced displacement constraint using a table field.

1: Setup

  1. On your desktop or the appropriate network drive, create a folder named plug.

  2. Click the link below:

    Download the part

  3. Extract the file to your plug folder.

  4. Start Simcenter 3D or NX.

  5. Open plug_sim.sim.

2: Reset dialog box memory

The options you select in dialog boxes are preserved for the next time you open the same dialog box within a given session. Restore the default settings to ensure that the dialog boxes are in the expected initial state for each step of the activity.

File

Preferences→User Interface

  • Options

  •   Reset Dialog Memory

  • OK

     
3: About the model

Use the Simulation Navigator to explore the existing model.

Modeling the plug

The model contains a two-body part that resembles a snap-in plug connector. You will use a large-displacement nonlinear solution to simulate the assembly of the connector.

The Simcenter Nastran structural solution type is SOL 601, 106 Advanced Nonlinear Statics.

Examine the contact objects

In the Simulation Navigator, the solution's Simulation Objects container lists two face contact objects.

The contact graphics are displayed in the graphics window. The source faces for the contact are on the plug, and the target faces are on the socket.

These contact simulation objects model the regions where the plug will contact the socket as the plug is displaced.

4: Edit the time step definition

For this solution, modify the number of time steps and time increment.

Note:

If you do not have the Simcenter Nastran Structural SOL 601,106 Advanced Nonlinear Statics solver installed, skip to the next section, Apply a time-dependent enforced displacement constraint.

  Modeling Objects (Home tab→Properties group)

  •  

  • Time Step1

  • Edit

  •  

     

  • Number of Time Steps

    20

  • Time Increment

    0.05

    The default units are seconds.

  • OK

     Time Step dialog box

  • Close

     Modeling Objects Manager dialog box

5: Apply a time-dependent enforced displacement constraint

  Simulation Navigator

  • plug_fem.fem

  • 3D Collectors (hide)

    Tip:

    Hiding the 3D meshes makes it easier to select the polygon face at the base of the socket.

  Enforced Displacement Constraint (Loads and Conditions group→ Constraint Type list)

  • Type

    Components

  • Type Filter (Top Border bar)

    Mesh Point

  • the mesh point at the top of the plug

  •  

     

  • Displacement CSYS

    Existing

  •  

     

  • DOF1

    0

  • DOF2

    0

  • DOF4

    0

  • DOF5

    0

  • DOF6

    0

  •   (DOF3)

  •   New Field→Table

  •  

    Name

    Plug Motion

  •  

  • Independent

    Time

  •  

    The table has three columns: Row ID, time (s), and length (mm).

  • (box under the table)

    0,0; 1,-21
    Tip:

    Use commas to separate values in a row, and use semicolons to separate rows.

  • Accept Edit

    The table displays displacement values at two different times:

    Row ID

    time (s)

    length (mm)

    1

    0

    0

    2

    1

    -21

  • OK

     Table Field dialog box

  •  

      (DOF3)

  •   Plot XY

  •   Create New Window (Viewport dialog box)

  •   Graph Window 1

  • OK

     Enforced Displacement Constraint dialog box

 

The enforced motion is defined at the mesh point.

  Save

At this point, if the Simcenter Nastran SOL 601, 106 Advanced Nonlinear Statics solver is installed, you can solve the model.

File

  • Close→All Parts