Creating Torsion Springs

You can create a torsion spring or a torsion bar to create an angular spring between bodies and simulate their elastic behavior when submitted to loads.

Before you begin:
  • Create at least two bodies.
  • Create a mechanism.
See Also
About Springs
  1. From the Machine Elements section of the action bar, click Spring .
    In the tree, the spring element appears under the Machine Elements node of the active mechanism.
  2. Select Torsion .
  3. From the Location section, specify how to locate or position the spring in the mechanism (the spring ends are attached to the specified locations on the respective bodies):
    1. Specify the Base marker, which is the first attachment location on the connecting body.
    2. Specify the End marker, which is the second attachment location on the connecting body.
    3. Specify the Axis direction, which defines the axis direction with respect to the Base marker reference system.
  4. From the Spring Angle options, select one of the following:
    OptionDescription
    Unloaded Nominal condition of the spring free of external loads.
    Preloaded Assembled configuration with a known applied preload.

    The spring angle is measured between the spring ends about the spring axis.

  5. If you selected Unloaded from the Spring Angle options, enter the value for the Free angle.

    The Free angle is the angle measured between the Base marker and the End marker in the unloaded configuration.

  6. If you selected Preloaded from the Spring Angle options, do the following:
    1. Enter the value for the Assembled angle, which is the angle measured between the Base marker and the End marker in the assembled configuration.
    2. Enter the value for the corresponding Preload torque, which is the torque applied about the Base marker to maintain the spring in the assembled configuration.

      The app calculates the actual free angle of the spring automatically based the preloaded configuration.

  7. From the Elastic Properties options, specify the Torsional spring rate, which is the stiffness in the axis direction (along the spring axis). You can select Value input to enter a constant value for the spring stiffness or Function to define the torsional stiffness about the spring axis.
  8. Optional: From the Damping Properties options, enter a value for the Damping constant, which is the material damping of the spring.

    This option provides the slight damping inherent in any physical coil spring; it is not meant to define a detailed damper. Entering a value of 0 or a value that is too low can cause undamped or weekly damped oscillations of the spring even for small forces or torques.

  9. Click OK.