June 6, 2022 at 9:58 amFAQParticipant
In a full harmonic analysis, DMPRAT did not actually produce a uniform ratio to critical damping value. For a harmonic analysis based on a single mode the damping it produces is greater than the ratio to critical for frequencies below resonance and less than the ratio to critical for frequencies above resonance. You can see this in Equation 14-22 of the MAPDL Theory Manual. The term (2/OMEGA)mj is the material dependent form of DMPRAT. As you can see it is divided by the driving frequency, not by the natural frequency as it would be if it was truly a ratio to the critical frequency. So it gets smaller as OMEGA gets larger and is only equal to the ratio to the critical frequency when OMEGA = omega at resonance for a single mode analysis. To avoid the impression that DMPRAT produces a ratio to the critical frequency we undocumented it. What we do now with DMPSTR is consistent with other codes and common terminology.
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 1 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?
- In Workbench Mechanical, how can I obtain strain energy output for Modal analysis?
- Is it possible to perform a sine-on-random vibration analysis in either Mechanical or Mechanical APDL?
- ANSYS Mechanical: Vibration Housing Noise
- In a Modal Analysis of Mechanical, why aren’t the Participation Factors Summary under Solution Information displayed?
- How to apply application-based settings to improve the performance and robustness of transient structural analyses?
- How to define variable thickness shell elements in ANSYS Mechanical? Is there any verification example of the variable thickness shell modal analysis available?
- Why does the prestress from Static analysis does not add up to the stress in Random Vibration analysis?