Lumped Model of a Vehicle Suspension System
In this example, a lumped model of a vehicle suspension system having 11 degrees of freedom is analyzed. The _Mass_, _Spring_, and _Damper_ nodes of the _Lumped Mechanical System_ interface are used to model the wheels, including suspension system as well as the seats with a passenger. The vehicle body, having 3 degrees of freedom, is modeled as a rigid body in the _Multibody Dynamics_ ...
Vibrations in a Compound Gear Train
This model simulates vibrations in a compound gear train. Spur gears, used to model the gear train, are mounted on rigid shafts. The shafts are supported by an elastic housing at both ends. The gear mesh is assumed to be elastic with varying stiffness, which is the source of vibration. A transient analysis is performed to compute the dynamics of the gears as well as the vibrations in the ...
Truck Mounted Crane
Many trucks are equipped with cranes for load handling. Such cranes have a number of hydraulic cylinders, controlling the motion, and several mechanisms. The cylinders and mechanisms that make up the crane are subjected to large forces when handling heavy loads. In order to determine the load carrying capacity, these forces must be computed. This model uses the Multibody Dynamics Module, ...
Differential Gear Mechanism
This model simulates the mechanism of a differential gear used in cars and other wheeled vehicles. A differential allows the outer drive wheel to rotate faster than the inner drive wheel during a turn. This is necessary when a vehicle turns in order to allow the wheel that is traveling along the outside of the turning curve to roll faster and to cover greater distance than the wheel on the ...
Modeling of Centrifugal Governor
A centrifugal governor is used to control the speed of rotating machinery. One of the most common applications is in controlling the RPM of an engine by regulating the fuel supply. This model illustrates the functioning of a spring loaded centrifugal governor. The dynamics of the governor are analyzed under the influence of a centrifugal force, spring force, and damping force. The sleeve ...
Modeling a Radial Cam Based Valve Opening Mechanism
In this example, a spring-loaded valve-opening mechanism consisting of a rocker arm and a radial cam is studied. All of the system components are modeled as rigid and are connected through prismatic, hinge, and slot joints. The cam-follower connection as well as other joint connections are modeled using built-in nodes in the _Multibody Dynamics_ interface. A transient analysis is performed for ...
Simulating the Motion of a Bicycle on a Flat Surface
This model demonstrates the motion of a bicycle with a hands-free rider when given an initial forward velocity and perturbed with a lean about the forward axis. This is implemented through the Multibody Dynamics module in COMSOL. The wheels of the bicycle have been modelled assuming knife-edge contact with the ground and pure rolling constraints have been implemented. Stability analysis was ...
Rolling of a Rigid Wheel
The purpose of this model is to demonstrate pure rolling of a rigid wheel when given an initial forward velocity together with a prescribed lean about this direction. It is assumed that the the rolling motion of the wheel is not affected by contact such that all three components of the velocity at the point of contact with the ground are zero. In order to achieve this, the velocity constraints ...
Centrifugal Governor Simulator
Centrifugal governors, a specific type of governor, control the speed of an engine by regulating the amount of admitted fuel. In order to maintain a near-constant speed, regardless of the load or fuel supply conditions, centrifugal governors use the principle of proportional control. While the governor is in operation, it is critical that it quickly reaches a new steady-state configuration. ...
Hinge Joint Assembly
This example illustrates how to model a barrel hinge connecting two solid objects in an assembly. In this model, the details of the connection are not the focus of the analysis, therefore, the hinge joint is modeled using a Joint feature in the Multibody Dynamics Module. The connected parts can be either rigid or flexible or a combination as shown in this model.