Spring PropertyManager

Springs are simulation elements that move components around an assembly by simulating the effects of various types of springs.

To open the Spring PropertyManager:

Click Spring (MotionManager toolbar).

Spring Type

PM_Linear.gif Linear Spring (Basic Motion and Motion Analysis only). Represents forces acting between two components over a distance and along a particular direction. SOLIDWORKS Motion:
  • Calculates the spring forces based on the distance between the locations of the two components
  • Applies a force to the first part you select
  • Applies an equal and opposite force along the line of sight of the second part you select
PM_Rotary-Torsional.gif Torsional Spring (Motion Analysis only). Represents torsional forces acting between two components. SOLIDWORKS Motion:
  • Calculates the spring moments, based on the angle between the two parts about the specified axis
  • Applies a moment about the specified axis to the first part you select
  • Applies an equal and opposite reaction moment to the second part you select

Spring Parameters

Linear springs selection box Lists the pair of features defining the spring endpoints
Torsional springs first selection box Lists the feature defining one end of the spring and the torque direction. Select a second feature only to change the torque direction.
Torsional springs second selection box Lists an optional second feature that defines the spring. Leave this selection empty to attach the spring to ground.
Exponent of Spring Force Expression Based on the Functional Expressions for Springs.
Spring Constant Based on the Functional Expressions for Springs.
Free Length (Linear springs). Based on the Functional Expressions for Springs. The initial distance is the distance between the parts as currently displayed in the graphics area. Select Update to model changes to have the free length dynamically update to model changes while the PropertyManager is open.
Free Angle (Torsional springs). Based on the Functional Expressions for Springs, specifies the angle between the torsion spring endpoints when not subject to load.

Damper

Select the Damper section (Motion Analysis only) to allow entry of values.
  • Select the Exponent of Damper Force Expression based on the Functional Expressions for Dampers.
  • Set the Damping Constant based on the Functional Expressions for Dampers.

Display

You can view the display values only when the Spring PropertyManager is open, or when you calculate the study.

Coil Diameter
Number of Coils
Wire Diameter

Load-bearing Faces

Click under Load references, and select components in the graphic area for Load-bearing Faces/Edges to transfer them to SOLIDWORKS Simulation.

Notes

  • Springs apply a force to a component. A spring with a higher spring constant moves a component faster than a spring with a lower spring constant. A component with a smaller mass moves faster than a component with a larger mass when acted upon by an equal strength spring.
  • The spring does not exert any force when its length is equal to its free length.
  • Motion due to motors supersedes motion due to springs. If you have a motor moving a component to the left and a spring pulling a component to the right, the component moves to the left, and the power consumption of the motor increases.

Functional Expressions for Spring Forces

  • Linear Spring: -K*ABS((X-Xo)**n)*SIGN(1,X-Xo)+Fo
  • Torsional Spring: -KT*ABS((Theta-Thetao)**n)*SIGN(1,Theta-Theatao)+To
In these expressions:
K is the Linear Spring Constant.
KT is the Torsional Spring Constant.
X is the current distance between parts at the attachment points.
Theta is the current angle between the parts, about the user-defined spring axis.
Xo defines the reference length for the spring. If the reference force of the spring is zero, Xo is the free length.
Thetao defines the reference angle for the torsional spring. If the reference torque of the spring is zero, Thetao is the free angle.
Fo specifies the reference force at Xo.
To specifies the reference torque of the torsional spring at Thetao.
n is the Exponent. For example, if the spring force = -kx2, then n = 2. Valid options are <-4,-3,-2,-1,1,2,3,4>.