Spring and Damper
Use the Spring and Damper subnode to apply elastic and viscous forces to restrict and control the relative motion on joint. You can also use a dashpot to model various kind of losses in the joint. This node can be added more than once if required, and the effects will then be superimposed. Each joint type has different settings sections.
The Spring and Damper subnode can be added to the Prismatic Joint, Hinge Joint, Cylindrical Joint, Screw Joint, Planar Joint, Ball Joint, Slot Joint, and Reduced Slot Joint. The contents of the settings sections will differ between different joint types
The Theory for Springs and Dampers on Joints section describes the theory for each of the different types of springs and dampers: translational, rotational, inclination angle, and axial rotation.
Spring and Damper: Translational
This section is available for the Prismatic Joint, Cylindrical Joint, Screw Joint, Planar Joint, Slot Joint, and Reduced Slot Joint nodes.
Select a Spring typeSpring constant or Force as function of extension.
For Spring constant, enter a value of ku.
For Force as function of extension, enter an expression for Fs. The expression can be a function of the spring extension. The built-in variable for the spring extension has the form <physicsName>.<JointTag>.<SpringAndDamperTag>.us (for example, mbd.prj1.sd1.us).
To add a predeformation of the spring, enter Predeformation u0. To add viscous damping in a dynamic analysis, enter a value or expression for the Damping coefficient cu.
For the Planar Joint, enter values or expressions for the Initial spring axis es0. Also select the Initial damper axisSame as spring axis or User defined. For User defined enter values or expressions for ed0.
Spring and Damper: Rotational
This section is available for the Hinge Joint, Cylindrical Joint, Screw Joint, Planar Joint, and Reduced Slot Joint nodes.
Select a Spring typeSpring constant or Moment as function of rotation.
For Spring constant, enter a value of kθ.
For Moment as function of rotation, enter an expression for Ms. The expression can be a function of the spring rotation. The built-in variable for the spring rotation has the form <physicsName>.<JointTag>.<SpringAndDamperTag>.ths (for example, mbd.hgj1.sd1.ths).
To add a predeformation of the spring, enter Predeformation θ0. To add viscous damping in a dynamic analysis, enter a value or expression for the Damping coefficient cθ.
Spring and Damper: Inclination Angle
This section is available for Ball Joint and Slot Joint nodes.
Select the Initial reference axisInitial source axis, Initial destination axis, or User defined. For User defined enter values for eR0.
Select a Spring typeSpring constant or Moment as function of rotation.
For Spring constant, enter a value of kθ.
For Moment as function of rotation, enter an expression for Ms. The expression can be a function of the spring rotation. The built-in variable for the spring rotation has the form <physicsName>.<JointTag>.<SpringAndDamperTag>.ths (for example, mbd.blj1.sd1.ths).
To add a predeformation of the spring, enter Predeformation θ0. To add viscous damping in a dynamic analysis, enter a value or expression for the Damping coefficient cθ.
Spring and Damper: Axial Rotation
This section is available for Ball Joint and Slot Joint nodes.
Select a Spring typeSpring constant or Moment as function of rotation.
For Spring constant, enter a value of kψ.
For Moment as function of rotation, enter an expression for Ms. The expression can be a function of the spring rotation. The built-in variable for the spring rotation has the form <physicsName>.<JointTag>.<SpringAndDamperTag>.psis (for example, mbd.blj1.sd1.psis).
To add a predeformation of the spring, enter Predeformation ψ0. To add viscous damping in a dynamic analysis, enter a value or expression for the Damping coefficient cψ.
Location in User Interface
Context Menus
Ribbon
Physics tab with Prismatic Joint, Hinge Joint, Cylindrical Joint, Screw Joint, Planar Joint, Ball Joint, Slot Joint, or Reduced Slot Joint selected in the model tree: