Add a Spring Foundation subnode to specify a spring or damper connecting the rigid connector to a fixed ground. The spring can act at an arbitrary position in space. A translational spring implicitly contributes also to the moment if it is not applied at the center of rotation of the rigid connector. The data that you specify is interpreted in the selected coordinate system.

Select an option from the list: Center of rotation or User defined. This is the location where the spring is attached.

Select the Offset check box to add an optional offset vector to the definition of the location. Enter values for the offset vector Xoffset.

Select a Spring type — Spring constant or Force as function of extension.

When Spring constant is selected, the translational spring matrix can be entered as Isotropic, Diagonal, Symmetric, or Anisotropic. For Isotropic the same spring constant is used in all the diagonal elements of the spring matrix.

When Force as function of extension is selected, enter the force vector Fs. It must be a a function of the built-in variables describing the spring extension. The default value indicates the correct variable name, for example solid.rig1.uspring1_spf1.

Select a Spring type — Spring constant or Moment as function of rotation.

When Spring constant is selected, the rotational spring matrix can be entered as Isotropic, Diagonal, Symmetric, or Anisotropic. For Isotropic the same spring constant is used in all the diagonal elements of the spring matrix.

When Moment as function of rotation is selected, enter the moment vector Ms. It must be a a function of the built-in variables describing the spring extension. The default value indicates the correct variable name, for example solid.rig1.thspring1_spf1.

From the Loss factor type list, select Scalar (Same for all components) or Individual components.

All settings in the Rotational Loss Factor Damping section are analogous to the corresponding settings in the Loss Factor section. In 2D, only one scalar loss factor, corresponding to rotation around the out-of-plane axis, is given.

Select Isotropic, Diagonal, Symmetric, or Anisotropic, then enter values or expressions for the damping constants du in the table. If you select Isotropic, the effect is the same as when you selecting Diagonal and enter the same value for all diagonal elements.

All settings in the Viscous Rotational Damping section are analogous to the corresponding settings in the Viscous Damping section. In 2D, only one scalar viscous damping, corresponding to rotation around the out-of-plane axis, is given.

Physics tab with Rigid Connector node selected in the model tree:
Attributes>Spring Foundation