Mechanism Design and Mechanism Dynamics > Mechanism Design > Using Analysis Results > Playback > About Display Arrows
About Display Arrows
When you play back your analysis results, you can display three-dimensional arrows that represent the magnitude and direction of the measures, forces, torques, gravity, and force motors associated with your analysis. Use these arrows to see the relative effect of loads on your mechanism. Single-headed arrows are used for force, linear velocity, and linear acceleration vectors. Double-headed arrows are used for moment, angular velocity and angular acceleration vectors. The color of the arrow depends on the type of measure or load. You must have a Mechanism Dynamics license to use arrows in analysis results.
As you play back your analysis results, the size of the arrow reflects the calculated value of the measure, force, or torque. The direction of the arrow changes as the calculated vector direction changes.
If you select several measures or input loads, the selection is displayed with the largest value within each type as the largest arrow. In addition, model size affects the initial arrow size. The default arrow size, which is the size of the largest arrow within a type at 100% scale, is proportional to the characteristic length of the model.
Tip: The default size of an arrow is based on the value of the measure or input load at the beginning of the analysis. If your measure or input load covers a large range of values during an analysis, the arrows can become unacceptably large or disappear. You may, therefore, need to readjust the scale and rerun the analysis to get a more useful animation. If you are preparing an animation for a presentation, you may want to use the Movie Schedule tab to remove those parts of the analysis in which the arrows become too big or too small.
Use these items on the Display Arrows tab of the Playbacks dialog box to select, label, and change arrow size:
Measures—Select a measure from the list. The list includes measures that you defined for the analysis. Only those measures that use the Each time step evaluation method appear.
Input Loads—Select an input load from the list. The list includes loads that you defined for the selected analysis or playback.
Scale—Select a category from the list and adjust the initial size of the arrows in that category by entering a value in the entry box or by turning the wheel. No arrow is displayed when the minimum value of 0% is chosen. There is no maximum size limit. You can select display arrows for Force, Moment, Velocity, Acceleration, or Separation.
Annotation—Select Name to display the names of measures or input loads during playback. Select Value to include the value. The displayed value updates as it changes during the playback.