Plotting the Linear Displacement, Velocity, or Acceleration of a Part

You can plot the linear displacement, velocity, or acceleration of a moving part as it moves relative to another part or relative to the assembly origin.

1. From a Motion Analysis study, click Results and Plots (MotionManager toolbar).
2. In the PropertyManager under Result, for Category, select Displacement/Velocity/Acceleration.
3. For Subcategory, select one of the following:
   • Linear Displacement
   • Linear Velocity
   • Linear Acceleration
4. For Select result component, select an option:
   • X Component, Y Component, or Z Component to calculate the magnitude of the result in the selected direction.
     Optionally, you can select a reference part in Component to define XYZ directions to plot the result relative to the coordinates of that part.
   • Magnitude to resolve the magnitude in the direction of the result vector in rectangular coordinates.
   • Radial Component (Linear Velocity only), to resolve the radial component of the velocity vector in polar coordinates.
   • Tangential Component (Linear Acceleration only), to specify the component of the acceleration vector tangent to the path of motion.
   • Normal Component (Linear Acceleration only), to specify the component of the acceleration vector normal to the path of motion.
5. Select features to use in calculating results.
   • When the results are calculated, the result components are in the global direction unless you select a nonfixed or grounded Component to define XYZ directions.

     Global directions are the X, Y, and Z directions of the triad that displays in the graphics area.

   • Selected part origins are indicated with a small sphere .

     The origin is difficult to see when using a white background.

   • Select one face:
     For Linear Velocity and Linear Acceleration, the result considers the center of mass for the part when the center of mass is specified.

     To specify the center of mass, click Tools > Evaluate > Mass Properties .

     Linear Displacement	The result is the position of the part origin relative to the assembly origin.
     Linear Velocity	The result is the absolute velocity of the center of mass of the part.
     Linear Acceleration	The result is the absolute acceleration of the center of mass of the part.

   • Select two faces:

     Linear Displacement	The result is the position of the part origin of the first face relative to the part origin of the second face.
     Linear Velocity	The result is the difference of the absolute velocities of the center of mass of the first face and the center of mass of the second face.
     Linear Acceleration	The result is the difference of the absolute accelerations of the center of mass of the first face and the center of mass of the second face.

   • Select one point, vertex, or edge:
     The corresponding location for points or vertices is the point or vertex.

     The corresponding location for edges depends on the edge type. For example, for a straight edge, the corresponding location is the midpoint. For a circular edge, the corresponding location is the center. For other types of edges, refer to the location of the symbol.

     Linear Displacement	The result is the position of the corresponding location relative to the assembly origin.
     Linear Velocity	The result is the absolute velocity of the corresponding location relative to the assembly origin.
     Linear Acceleration	The result is the absolute acceleration of the corresponding location relative to the assembly origin.

   • Select two points, vertices, or edges:
     The corresponding location for points or vertices is the point vertex.

     The corresponding location for edges depends on the edge type. For example, for a straight edge, the corresponding location is the midpoint. For a circular edge, the corresponding location is the center. For other types of edges, refer to the location of the symbol.

     Linear Displacement	The result is the position of the first location relative to the second location.
     Linear Velocity	The result is the difference of the absolute velocities of the first location and the second location.
     Linear Acceleration	The result is the difference of the absolute accelerations of the first corresponding location and the second location.

   • Select a motor:

     In the Motor PropertyManager, you can define the Motor Location and select a frame of reference for the motor motion for Component to Move Relative to

     To use a frame of reference from the assembly origin, leave Component to Move Relative to blank.

     For a suppressed Linear Motor, you can have results for linear displacement, linear velocity, or linear acceleration. You can use a suppressed Linear Motor to obtain the linear displacement, linear velocity, or linear acceleration of any location where you can define a Linear Motor.

     Linear Displacement	The result is the current motor position relative to the motor position at 0 seconds. The result uses the frame of reference of Component to Move Relative to when specified for the motor. When Component to Move Relative to is blank, the result uses the frame of reference of the assembly.
     Linear Velocity	When you select a Linear Motor and specify Component to Move Relative to, the result is the difference of the absolute velocities of the current motor position and the motor position at 0 seconds relative to Component to Move Relative to. The result is in the direction of the component specified in Component to Move Relative to. When you select a Linear Motor and do not specify Component to Move Relative to, the result is the absolute velocity of the motor location.
     Linear Acceleration	If you select a Linear Motor and Component to Move Relative to is not specified, the result is the absolute acceleration of the motor location.

   • Select a mate:

     You specify the mated entities when you define the mate in the Mate PropertyManager.

     The result is in the local direction of the mate, as shown by the triad unless you select a nonfixed or grounded Component to define XYZ directions.

     The geometric center of an axis is at the center of the axis.

     Linear Displacement	The result is the position of the geometric center of the first entity relative to the geometric center of the second entity. This result is not a displacement of the mate and the value of the result is typically not null at 0 seconds.
     Linear Velocity	The result gives the relative velocity of the geometric center of the first entity relative to the geometric center of the second entity.
     Linear Acceleration	The result is the relative acceleration of the geometric center of the first entity relative to the geometric center of the second entity. Normal Component is the component of the acceleration vector normal to the path of motion. This component causes the velocity vector to change direction. Magnitude does not change the direction. For example, you have a circular motion around an axis of a point at a distance R rotating at w rad/s. The Normal Component of linear acceleration is Rw², which corresponds to the centripetal acceleration. Tangential Component is the component of the acceleration vector tangential to the path of motion. This component causes the magnitude of the velocity vector to change. For example, you have a circular motion around an axis of a point at a constant angular velocity. The Tangential Component of linear acceleration is null.

   • Select a Linear Spring:

     Linear Displacement	The result is the distance between the two selections in the definition of the Linear Spring. The result is in the reference frame of the Linear Spring unless you select a Component to Move Relative to.
     Linear Velocity	The result is the difference of the relative velocities of the two selections in the definition of the Linear Spring. The result is in the reference frame of the Linear Spring unless you select a Component to Move Relative to.
     Linear Acceleration	The result is the difference of the absolute accelerations of the two selections in the definition of the Linear Spring. The result is in the reference frame of the Linear Spring unless you select a Component to Move Relative to.
6. Select the Plot Results options and click .
   The result appears in the MotionManager design tree.
7. Click Calculate (MotionManager toolbar).