What Can the Multibody Dynamics Module Do?
The Multibody Dynamics Module can be used to model the static and dynamic behavior of rigid or flexible components connected using joints with certain degrees of freedom. The components can then undergo complex combinations of translational and rotational motions with respect to one another. Some major application areas are for automotive applications, aerospace engineering, biomechanics, biomedical instruments, robotics, and general dynamic simulations.
The main components of this module are The Multibody Dynamics Interface, The Lumped Mechanical System Interface, and The Wire Interface.
The Multibody Dynamics interface is used to model assemblies of flexible components, rigid components, or the combination of both. Flexible components can be defined through solid and wire elements, and in combination with the Structural Mechanics Module, also shell or beam elements. Flexible components can also have geometric and material nonlinearity. With this physics interface, you can simultaneously perform a system analysis and a detailed component analysis of a mechanical system.
The features that are used to model connections are joints, attachments, rigid domains, gears, springs, and dampers. The joints that connect the different structural parts can have many different properties, including elastic connections, viscous damping, friction losses, stop conditions, and lock conditions.
There are several types of joints available for modeling different types of connections between components. Attachments are used by joints to establish a connection primarily between flexible components, but can also be used with rigid bodies. A rigid domain models a rigid component, and it is directly used in a joint to establish its connection with another rigid or a flexible component. Elastic springs and viscous dampers can also be used to connect rigid or flexible components.
This interface is also used to model geared systems for power transmission. There are several types of gears available to connect and transfer power from one shaft to another. The gear pairs that connect two gears can have many different properties, including mesh stiffness and damping, static transmission error, backlash, and friction losses. Similarly chain drives are also possible to model for power transmission. The roller chain and sprocket assembly is available to connect and transfer power from one shaft to another. The roller chain sprocket assembly can have different parts rigid or elastic and based on that different contact methods between chain and sprocket, roller center based and mesh based, are available.
The results obtained from the gear or chain dynamics can be further used for the fatigue analysis of the gear/sprocket or for the acoustic analysis to find out the noise emitted by the system.
This interface has a dedicated feature for modeling frictional contact between rigid bodies. The rigid body contact functionality is primarily for modeling the contact between standard rigid shaped bodies. It is much robust and faster compared to a standard mesh-based contact.
The Multibody Dynamics interface can be coupled to a heat transfer, acoustics, or fluid flow interface through multiphysics coupling nodes.
The Lumped Mechanical System interface is intended to model displacements and forces in a mechanical system using a circuit representation with lumped components such as masses, springs, and dampers. In addition to the displacement and force sources in the system, terminal nodes are used to define forces, displacements, velocities, accelerations, or impedances as boundary conditions.
In the COMSOL Multiphysics Reference Manual:
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Studies and Solvers
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The Physics Interfaces
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For a list of all the core physics interfaces included with a COMSOL Multiphysics license, see Physics Interface Guide.