Can you limit the expansion of modes to only those modes with a high participation factors by using the MXPAND,,,,,,.01,,MODM command to ignore modes below a certain modal mass fraction?
-
-
June 6, 2022 at 9:58 am
FAQ
ParticipantYes, but you have to do the modal expansion is a separate solution pass as shown in the following input.
/prep7
et,1,185,,2
mp,ex,1,1e7
mp,nuxy,1,.3
mp,dens,1,.0003block,,20,,2,,1
esize,1
vmesh,1
nsel,s,loc,x,0
d,all,all
nsel,all
fini
! Obtain the Modal Solution
/solu
antype, MODAL
modopt, LANB,12 ! Block Lanczos
solve
finish! Perform the modal selection and expansion
/solu
antype, MODAL, RESTART
mxpand,,,, yes,,, MODM ! Mode selection is based on the modal effective mass, and element
! results are requested
modseloption,no, no,0.90, no,no,no ! Only direction X is selected, a minimum of 90% of the total
! mass is requested in this direction
solve
finish
-

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.
- How can I change the normalization method of the vibration modes from modal analysis?
- In the results of a modal analysis, how can I define that a frequency is an output parameter ?
- Why does the prestress from Static analysis does not add up to the stress in Random Vibration analysis?
- 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 ?
- What does the warning “Diagonal of the mass matrix is missing in file” indicate when using RSTMAC command?
- Why is damped frequency is lower than undamped frequency with viscous damping but larger with structural damping?
- How do I get a frequency response of acceleration in the radial direction of a cylinder?
- In a Modal Analysis of Mechanical, why aren’t the Participation Factors Summary under Solution Information displayed?
- What is mass moment of inertia in Point Mass used for?
- How to solve for harmonic response at a specific frequency in Workbench?
© 2023 Copyright ANSYS, Inc. All rights reserved.