Dynamics Simulation

This command calculates the simulation before viewing.

Creation stages / Use:

Click the icon or select the Simulation > Dynamic simulation.. command from the drop-down menu.

Check or uncheck Auto refresh. The slightest modification (joints, tasks, forces, dampers, velocity, etc.) restarts the calculation of the simulation, which can slow things down considerably.
Select the start configuration in the drop down list. Several configurations may be available, with different part positions.
In the drop down list, select the linear or angular start velocity, if it is defined.
Select the scenario in the drop-down list.
Enter the duration of the simulation. If a scenario has been selected, the duration of the simulation does not need to be entered, it is defined by the scenario.
Enter the number of positions calculated per second. The trajectory points are pre-calculated. The greater the number of positions, the more accurate the trajectory. Conversely, too few positions will create a segmented trajectory.
Enter the calculation steps per position. When the displacement is too large in relation to the number of positions calculated, the calculation can be fine-tuned by modifying the pitch. It represents the interval between two position calculations of the mechanism. The lower the calculation, the more accurate the trajectories.
Enter the damping factor which provides a damper notion to the mechanism (frictions, energy loss...). Globally, the damping factor applies to the whole mechanism.
Check or uncheck Overconstrained. (please read the warning below).
Check or uncheck Unknown physical properties. If this option is unchecked, all parts must have a material and their physical properties activated (mass, ...) if not, the simulation will be invalid. If the option is checked, the simulation can be ran even if some parts have no mass, for example to create a static analysis when mass effects are negligible regarding the applied efforts or when movements are very slow.
Check the Viewer option to be able to play the simulation when exporting the assembly as visualization format, or in case of opening it with TopSolid'Pdm Explorer.
Validate.

Increasing the number of positions per second and/or the steps by position gives a more precise result but on the other hand it takes more time to calculate.
For reasons of performance, you are advised not to activate Auto refresh. If this option is checked, editing, deleting, adding a joint or task causes a new simulation calculation. This calculation time may be long, depending on the complexity of the assembly and the accuracy of the calculation required.

Available Options:

Collisions:

Check this option in order to manage them.

Select the type of representation on which to verify the collisions.
Select the parts.
If you check Invalid if Collision, the simulation will be invalid when it is recalculated, if there are collisions. Otherwise, you will only know if there are collisions when viewing the simulation.

The calculation of collisions is very intensive on system resources. For this reason, it is recommended that you only select parts that can enter into collision.
In a mechanism, only collisions between rigid groups are detected. If there are collisions between parts of a same rigid group, they will not be calculated. They will have to be detected in static mode (Design stage instead of Mechanism stage).

Modifications / Additional information:

Using the popup menu, Auto refresh can be edited, deleted and checked or unchecked.

When the simulation is not updated, it is colored cyan in the entities tree. It must be refreshed (popup menu) before using.

The density, the center of density, moments of inertia must be attributed to the parts and assembly for the dynamic simulation to function.
Overconstrained: Calculating an overconstrained simulation is prohibited by default. But you can calculate it by checking this option, recognizing that the result of this overconstrained simulation could be corrupt. It is highly recommended to modify the assembly to no longer be overconstrained.

CAUTION: The results of the simulations are given for your information and can be tainted with errors (for example, because it is outside the validation domain of the achieved approximations). Critical mechanisms must always be verified with another software (it is probably good that both give the same result). Furthermore, even if the result is exact, perhaps the simplifications achieved once the mechanism has been modeled are not verified in reality (friction, tolerance of parts, ...), therefore the final product must still be tested in an actual condition (verily extreme) before making it available to the user without risk.