Mechanism Design and Mechanism Dynamics > Mechanism Dynamics > Analyses > Dynamic Analyses > To Enter Preferences for Dynamic Analyses
To Enter Preferences for Dynamic Analyses
Use the Preferences tab on the Analysis Definition dialog box to specify time domain, locked entities, and initial configuration information for dynamic analyses.
You cannot specify a start time for dynamic analyses. Servo motors, springs, dampers, and gear pairs are active for the entire dynamic analysis. The analysis must begin from the time these are turned on, so that any effects from them are taken into account.
Select one of the options from the list under Graphical display. The parameters that you use to specify the time domain depend upon which item you select. Enter values as explained below to specify the time domain for your analysis:
Length and rate—Enter the Duration and Frame rate or Minimum Interval to define the analysis time domain.
* If you want to evaluate the positions, velocities, accelerations, and reaction forces of the entities in your mechanism at the beginning of your dynamic analysis, enter 0 for Duration. You can use this method as a quick check before running a longer dynamic analysis.
Length and frame count—Enter the Duration and Frame count to define the analysis time domain.
Rate and frame count—Enter the Frame count and Frame rate or Minimum interval to define the analysis time domain.
* Frame rate and Minimum interval are complements of each other. The length, frame count, frame rate, and interval of the motion run are related by the following formulas:
* Frame Rate = 1/Interval
* Frame Count = Frame Rate * Length + 1
Use the Locked entities area to specify which bodies or connections in your mechanism remain locked during your dynamic analysis. Locking bodies fixes the position of one body relative to another during the defined analysis. Locking connections removes the motion associated with the connection's DOF during the defined analysis. A disabled connection is temporarily suppressed and is ignored by the analysis.
Use the Initial configuration area to select configuration and velocity conditions for the start of your dynamic analysis. Select one of these options:
Click Current to use the positions of the bodies in the current screen configuration
Click I.C.State to select a previously saved initial condition. You can also preview the configuration associated with a selected initial condition.
You can run the analysis immediately after defining it. When you click Run, the analysis definition is checked for errors in the same way as when you click OK. The defined analysis is run but is not added to the model. When you click OK, the software finishes the definition, creates the analysis, and adds the analysis definition to the model.