About Mechanism Simulations

You can create or define several components to simulate a mechanism and analyze the simulation results.

This page discusses:

By default, opening a product assembly in xMotion Design results in the creation of:

  • a Motion Simulation object in the tree
  • a mechanism (if no mechanism is included in the product assembly)
  • an analysis case
  • a dynamics analysis step with default settings

The mechanism and analysis case are set as current. They are highlighted in the tree.

Simulation Elements

In the tree, the Model node is linked to a physical product that can include one or more mechanisms. Each mechanism contains a motion model definition including mechanism elements, such as bodies, joints, drivers, or machine elements.

The Scenario node includes one or more analysis cases, each made of one or several analysis steps. An analysis case is linked to a mechanism. Use the analysis steps to specify computation parameters for a mechanism, and to define kinematics or dynamics motions during the simulation.

The Results node lets you display the results of the computed simulations using plots. You can also replay the animation of analysis steps or export the animation to replay it in another app.

Kinematic and Dynamic Simulations

You can simulate a mechanism motion to predict its behavior and analyze the simulation results. You can perform two types of simulations: kinematic simulations and dynamic simulations.

Kinematic simulations compute the motion of the bodies included in the mechanism and according to the mechanism connections. The simulation considers the following mechanism properties:

  • Element positions
  • Element orientations
  • Velocities (translational and rotational)
  • Accelerations (translational and rotational)
Note: A kinematic simulation does not consider applied forces or external forces.

Dynamic simulations compute the motion of the bodies included in the mechanism according to the mechanism connections, as well as according to the following elements:

  • Applied forces (external forces)
  • Torques
  • Gravity
  • Body mass and inertia
  • Inertia forces and torques

A dynamic simulation associates forces and torques to accelerations.

Mechanism Update

Before previewing the animation of a mechanism or computing a mechanism simulation, make sure that the mechanism is up-to-date and solved.

  • For a mechanism generated from an assembly and updated according to the assembly, perform an update of the assembly before launching the calculation.
    Note: For more information, see Updating Mechanisms.
  • For a new or modified mechanism, solve the mechanism to ensure its consistency before launching the calculation.
    Note: For more information, see Solving Mechanisms and Solving the Initial State of Mechanisms.