Simulation Tab

Simulation Parameters:
(in IntelliMotion Builder and COSMOSMotion Options)

Duration or Time Increment

Specify one of the following:

• Duration: Enter the end time of the simulation.

• Time Increment: Enter the increment between simulation frames. Multiplying this value by the number of frames produces the simulation ending time.

Number of Frames

Enter the number of frames to be calculated during this simulation. A frame is a snapshot of the motion model at a specific point in time. COSMOSMotion only retrieves simulation results at frames.

The number of output steps per second that you specify increases as the speed of your mechanism increases. If you don't request an adequate number of output steps, you may miss a portion of the behavior of your mechanism. However, if your mechanism moves very slowly, you may want to specify fewer output steps per second. With a slow-moving mechanism, a large number of output steps per second may be unnecessary because events are happening slowly.

Notes:

• The number in this text box is the total number of output steps for your simulation, not the number of output steps per second.

• Do not confuse the speed at which the mechanism moves with the animation rate. A mechanism's speed is based on how fast its components are moving or changing direction. The animation rate is the number of frames per second that are displayed and is dependent on your computer hardware.

Animate during simulation

• If selected, the model is animated while the simulation is running.

• If not selected, the model does not move during the simulation.

Use mass properties stored with parts

• If selected, and mass properties have already been calculated for a part, then these mass properties are used for the simulation.

• If not selected, mass properties are recalculated for each part each time the simulation is run. This can result in significant computational time prior to the simulation starting to run.

Simulate
(only in IntelliMotion Builder)

Select to start the simulation.

Delete Results
(only in IntelliMotion Builder)

Select to delete the current simulation results and return to modeling mode.

Use Precise Geometry for 3D Contacts

Select to use precise surface geometry to detect contact, producing more accurate results, but longer solution times. If this option is not selected, you can specify a scaling factor to adjust the facet tolerance used in ADAMS/Solver. The scale factor can vary from 1 to 100. This factor is used to adjust several parameters, but the main parameter is the curvature tolerance for the faceted surfaces to the real geometry. A value of one gives the least accurate representation; a value of 100 gives the best representation available.

Note that a value of 100 does not indicate that the geometry is precise, only that the facet settings are at a maximum accuracy.

The best way to use the facet tolerance is to minimize error in resulting force/acceleration results. Click here to see an example of the contact force results between the cam and the rocker that can be generated using 3D contact in the valve-cam tutorial.