Create Linear Gap Elements

Create linear gaps between corresponding pairs of nodes from one plate to another plate along the axis of a local coordinate system.

Figure 1.


  1. From the menu bar, click Aerospace > Connections > Linear Gaps.
  2. Select the Dependent Nodes from the first plate.
  3. Select the Independent Nodes from the second plate.
  4. Assign the correct Tolerance, which is slightly bigger than the gap.
  5. Select the degree of freedom (DOF) for the MPC (1, 2, 3, 4, 5, or 6).
  6. Click Apply.
    A Nastran linear gap is created that consists of MPC, SPC, SPOINTS and SUPPORT. For example, the following cards are created.

    SPOINT 55 155 (two spoints 55, 155)

    SUPPORT 55 0 (support at one spoint)

    SPC 101106 155 0 .05 (spc at the other spoint with initial gap of 0.05, with DOF=0)

    $ SID G1 C1 A1 G2 C2 A2 (MPC for linear gap. In DOF = 2 for Nastran)

    MPC 101106 3 2 1.0 2 2 -1.0

    $ G3 C3 A3 G4 C4 A4

    55 0 1.0 155 0 -1.0

    Note: You can also use this tool to convert other types of 1D connector elements, such as CGAP, CBUSH, CELAS, to linear gap (MPC/SUPORT, SPC, SPOINT).
    Figure 2.