Why might a Modal analysis performed on unconstrained assembly not produce six rigid body modes with zero frequency?
-
-
January 25, 2023 at 7:34 am
FAQ
ParticipantIf penalty based contacts are used to tie the parts together, this could introduce artificial stiffness that can affect the free modes. In particular this could affect the three rotational modes. To avoid this try changing the contact formulation to MPC. This should result in six rigid body modes with zero frequency
-

Introducing Ansys Electronics Desktop on Ansys Cloud
The Watch & Learn video article provides an overview of cloud computing from Electronics Desktop and details the product licenses and subscriptions to ANSYS Cloud Service that are...

How to Create a Reflector for a Center High-Mounted Stop Lamp (CHMSL)
This video article demonstrates how to create a reflector for a center high-mounted stop lamp. Optical Part design in Ansys SPEOS enables the design and validation of multiple...

Introducing the GEKO Turbulence Model in Ansys Fluent
The GEKO (GEneralized K-Omega) turbulence model offers a flexible, robust, general-purpose approach to RANS turbulence modeling. Introducing 2 videos: Part 1Â provides background information on the model and a...

Postprocessing on Ansys EnSight
This video demonstrates exporting data from Fluent in EnSight Case Gold format, and it reviews the basic postprocessing capabilities of EnSight.
- Why is damped frequency is lower than undamped frequency with viscous damping but larger with structural damping?
- How can I specify acceleration at a node? Could I use the ‘big mass method’?
- How can I change the normalization method of the vibration modes from modal analysis?
- ANSYS Mechanical: Vibration Housing Noise
- Why does the prestress from Static analysis does not add up to the stress in Random Vibration analysis?
- In a Modal Analysis of Mechanical, why aren’t the Participation Factors Summary under Solution Information displayed?
- A Shock absorber is represented as spring element with damping constant. Modal analysis is performed using Reduced Damped (QRDAMP) solver. How to perform a Modal super position harmonic or transient analysis further ?
- Can you output the frequency response for a total deformation?
- Is it possible to perform a sine-on-random vibration analysis in either Mechanical or Mechanical APDL?
- In the results of a modal analysis, how can I define that a frequency is an output parameter ?
© 2023 Copyright ANSYS, Inc. All rights reserved.