9.9.1.3. Contact Force Name Page

../_images/image1933.png

Figure 9.133 Properties of SphereToFSurface dialog box

  • Definition of The Base Surface: Allows you to select the base contact geometry. The entities vary according to each contact force type.

  • Definition of The Action Surface: Allows you to select the action contact geometry. The entities vary according to each contact force type.

  • Force Display: Graphically displays the resultant force vector on the view window.

    • Inactive: The force graphical display is inactive.

    • Action: The force and torque which is generalized on the action body due to a contact force is displayed at a position. If the action body is a:

      • Flexible body, then the resultant contact force is displayed at the specified reference frame for contact.

      • Rigid body, then the contact force is displayed at the center marker of the action body.

        \(Q_a=\left\{ \begin{matrix} f_a \\ \tau_a \end{matrix} \right\} = \left\{\begin{matrix} f_n+f_f \\ \tilde{s}_{ac} (f_n+f_f) \end{matrix} \right\}\)

    • Base: The force and torque which is generalized on the base body due to a contact force is displayed at a position. If the base body is a:

      • Flexible body, then the resultant contact force is displayed at the specified reference frame for contact.

      • Rigid body, then the contact force is displayed at the center marker of the base body.

        \(Q_b=\left\{ \begin{matrix} f_b \\ \tau_b \end{matrix} \right\} = \left\{\begin{matrix} -f_a \\ -\tilde{s}_{bc} (f_n+f_f) \end{matrix} \right\}\)

    • Both: Simultaneously displays the action and reaction forces at the specified positions.

      ../_images/image1962.png

      Figure 9.134 Definition of contact force

  • Refresh: When the action or base contact geometry is changed, you can refresh the preview of information of specified contact geometry as using this function.

Contact surface

../_images/image1973.png

Figure 9.135 contact surface

Contact curve

../_images/image1984.png

Figure 9.136 Contact curve

A FFlex body such as a cable or wire, or a beam structure with circular cross section is used for a contact.

  • These Flexible bodies:

    • Have a cylindrical surface.

    • Is modeled with 1D finite element of beam.

  • The beam elements is:

    • Defined as a patch set

    • Used for flexible curve contacts.

  • The cross section of the curve for a contact is assumed as a circle.

    • So, the contact geometry can be approximated to the cylinder and sphere as shown in Figure 9.136.

    • Note that a contact point in the curve is linearly interpolated from two nodes.