Complete Flexibility in Analyzing Multibodies
Components of a system that undergo deformations can be modeled as flexible, while other components, or even parts of these components, can be specified as rigid. You can also provide your multibody dynamics design and analyses with nonlinear material properties by combining models in the Multibody Dynamics Module with either the Nonlinear Structural Materials Module or the Geomechanics Module. At the same time, the rest of the physics that you can model with COMSOL Multiphysics and the suite of application-specific modules, can be coupled to the physics described by the Multibody Dynamics Module, such as the effects of heat transfer or electrical phenomena.
Transient, frequency-domain, eigenfrequency, and stationary multibody dynamics analyses can be performed. Joints can be assigned linear/torsional springs with damping properties, applied forces and moments, and prescribed motion as a function of time. Analysis and postprocessing capabilities include:
- Relative displacement/rotation between two components and their velocities
- Reaction forces and moments at a joint
- Local and global coordinate system frames of reference
- Stresses and deformations in flexible bodies
- Fatigue analysis of critical flexible bodies by combining with the Fatigue Module
Often, motion between two components is restricted due to the presence or functions of other physical objects. Limiting and conditionally locking the relative motion can be specified for the joints in order to fully define and model these complex systems. In robotics, for example, the relative motion between two arms can be defined as a pre-defined function of time. Joints can also be spring-loaded and appropriate damping factors can be included in the Multibody Dynamics Module.
Multibody Dynamics Module
- Joints can be constrained to restrict the relative motion between the two connected components
- Joints can be locked to freeze the relative motion between the two connected components at the specified value
- Spring conditions can be applied on the relative motion at a joint, either at the equilibrium or with pre-deformation
- Lumped mechanical systems can be built, and can consist of masses, dampers, springs, and more
- Damping or dashpot conditions can be defined to specify losses on the relative motion at a joint
- Joints can be required to prescribe the relative motion between the connected components
- Frictional loss to a joint can be added for the joint types: Prismatic, Hinge, Cylindrical, Screw, Planar, and Ball.
- Cam-Follower condition
- Forces and moments can be applied to all types of joints at the attachments to the components
- Mechanisms can be initialized to translate and rotate rigidly with the given velocities about the specified center of rotation
- Part Library with parametric geometry parts for internal gears, external gears, and racks
- Engine dynamics
- Biomedical instruments
- Vehicle dynamics
- General dynamic simulations of mechanical assemblies
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Differential Gear Mechanism
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Assembly with a Hinge Joint
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