![]() These vibrations are transmitted to the gearbox housing through shafts and joints. For example, consider a gearbox in which the change in the gear mesh stiffness causes vibrations. Predicting the noise radiation from a dynamic system gives designers insight into the behavior of moving mechanisms early in the design process. The rotor orbit at two bearing locations is also shown (bottom-right).Īpplication Library path: Multibody_Dynamics_Module/Machinery_and_Robotics/induction_motor_vibration New Tutorial: Noise Radiation by a Compound Gear Train Plot of stresses in an induction motor's housing (top) and the magnetic flux density in the rotor (bottom-left). Note: This model also requires the AC/DC Module and Structural Mechanics Module. Due to resistive losses and loading torque on the shaft, the rotor will not revolve as fast as the stator windings, so an angular slip will occur. The torque is then used in the multibody dynamics model in order to compute the rotor speed, accounting for inertial effects. The rotational torque is calculated as a function of time. The electromagnetic simulation is modeled in 2D, whereas the multibody dynamics simulation is modeled in 3D. The air gap between the rotor and stator is asymmetric, resulting in vibrations in the motor. Induced currents in the rotor interact with the magnetic field that is produced by the coils to generate the driving torque on the rotor. In the Induction Motor Vibration tutorial model, eddy currents are induced in the rotor by time-harmonic currents in the stator windings and rotation of the rotor. The frequency spectrum of the normal acceleration at one of the points on the gearbox is also shown (bottom-left).Īpplication Library path: Multibody_Dynamics_Module/Automotive_and_Aerospace/gearbox_vibration_noise New Tutorial Model: Vibration in an Induction Motor The stresses in the gearbox housing and the sound pressure level in the surrounding air (top and bottom-right) of a 5-speed synchromesh gearbox inside a manual transmission vehicle. Solid Mechanics (3D, 2D, 2D axisymmetric).The Rigid Motion Suppression condition is available for the following physics interfaces: This feature automatically applies a set of suitable constraints based on the geometry model and physics interfaces. Now, the new Rigid Motion Suppression condition can be used for these types of analyses. Self-equilibrating models can be analyzed as long as the specifications of the constraints fulfill the following conditions: rigid body motions are not possible and no reaction forces are introduced. In cases where loads are self-equilibrating, the actual locations of where the required constraints are placed are not relevant. Automatic Suppression of Rigid Body Motion This will reduce the number of degrees of freedom when using structured meshes with higher-order elements in flexible domains. When modeling flexible parts in the Multibody Dynamics interface, you can choose to discretize by serendipity shape functions. Discretize by Serendipity Shape Functions This avoids having to change and reselect the joint node in the respective domain and Settings window. You can now use an Attachment option on a rigid domain, making it easier to switch between a rigid representation and an elastic representation. This is useful for extracting system matrices represented in a modal base for large multibody dynamics models. The Modal Reduced Order Model study type is now supported in the Multibody Dynamics interface. Voir la capture d'écran Modal Reduced Order Model Study Type Similarly, the two gears in a Gear Pair node and the two parts joined in a Spring-Damper node will also be highlighted when you select those corresponding nodes. ![]() This provides feedback on the correctness of the source and destination selections. When you select a Joint node in the model tree, the selected objects are now automatically highlighted in the Graphics window. When working with complex assemblies in the Multibody Dynamics interface, there may be many joints where each contains the selection of two rigid domains or attachments. Highlighting Selections in Multibody Dynamics Analyses Learn more about these tutorials and other multibody dynamics modeling improvements below. For users of the Multibody Dynamics Module, COMSOL Multiphysics ® version 5.3 brings a tutorial model that combines multibody dynamics with acoustics to simulate noise in a gearbox as well as a tutorial that combines the Multibody Dynamics Module with the AC/DC Module to simulate an induction motor.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |