Defining Spring Stiffness and Damping Properties

When defining spring properties for an Advanced or To Ground spring, click New or Edit on the Spring Properties dialog box. Creo Simulate displays the Spring Properties dialog box on which you can enter the following information:

• Name—The name for the spring property. Enter a name or accept the default name.

• Description—An optional description of the spring property.

• Compute Coupling Automatically—This option is selected by default and enables Creo Simulate to automatically account for the length of the spring and couples forces and moments with displacements and rotations as needed. Clear this option to ignore the length of the spring and to enter your own values for coupling forces and moments with displacements and rotations.

You cannot enter the coupling stiffness properties in FEM mode. The FEM mode enables the Compute Coupling Automatically option by default and does not let you disable it.

• Stiffness tab—The components on the Stiffness tab represent the extensional and torsional stiffness characteristics of the spring. To explicitly define the coupling stiffness of the spring, clear the Compute Coupling Automatically option. You should enter a non-zero value for at least one of the coupling items.

Enter non-negative values for the following fields along the specified principal axis relative to the spring's coordinate system:

Spring Stiffness Property	Field Name	Principal Axes
Extensional	Kxx	Along xx component
Extensional	Kyy	Along yy component
Extensional	Kzz	Along zz component
Torsional	Txx	Along xx component
Torsional	Tyy	Along yy component
Torsional	Tzz	Along zz component

If you clear the Compute Coupling Automatically option, Creo Simulate allows you to specify coupling by entering values for the coupling stiffness with KTxx, KTxy, KTxz, KTyy, KTyx, KTyz, KTzz, KTzx, KTzy, Kxy, Kxz, Kyz, Txy, Txz, and Tyz.

• Damping tab (FEM mode only)—Specify non-negative values for the following properties of the spring:

◦ Cxx—Specifies the xx component of the damping coefficient relative to the spring's coordinate system.

◦ Cyy—Specifies the yy component of the damping coefficient relative to the spring's coordinate system.

◦ Czz—Specifies the zz component of the damping coefficient relative to the spring's coordinate system.

For information on defining extensional and torsional stiffness for 2D and 3D models, see Defining Spring Properties for 2D and 3D Models.

Creo Simulate labels the stiffness components using Cartesian component directions. To review the equivalent component directions for cylindrical and spherical components, see Axis and Component Equivalents in Different Coordinate Systems.