Effective Mass Participation

Karthic_22061
Karthic_22061 Altair Community Member
edited October 2020 in Community Q&A

Hi All,

How to output the results for Effective Mass Participation Factor in modal Analysis ?

 

Is it sufficient to look for the first 6 to 10 modes or a couple of hundred Hz (say 500 Hz) ?

 

 

Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2018

    Use control card PARAM,EFFMAS,YES.

    Modal mass results written to .out file.

  • gopal_rathore
    gopal_rathore Altair Community Member
    edited June 2018

    Hi All,

    How to output the results for Effective Mass Participation Factor in modal Analysis ?

     

    Is it sufficient to look for the first 6 to 10 modes or a couple of hundred Hz (say 500 Hz) ?

     

     

    Hi,

    Selection of modes depend on your area of interest in frequency range , based on these you need to observe the mode shapes and also check the mass participation in that particular mode.

     

    Also try to understand based on your operating condition which mode would be more severe i.e the object has the tendency to have during the operating conditions.

     

    Are you working on a fixture design?

  • Karthic_22061
    Karthic_22061 Altair Community Member
    edited June 2018

    Thank you @gopal_rathore,

    Not fixture design.

    I came across a term  Effective Mass Participation Factor online.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited June 2018

    Hi @Karthic

     

    Number of modes and EMPF are interdependent. 

     

    Generally, a mode with higher EMPF is considered significant contributor and a cumulative EMPF more than 80% in any given response direction considered as sufficient. 

  • LOKESH KATARI
    LOKESH KATARI Altair Community Member
    edited October 2018

    i am trying calculate the EMPF but its not showing anything in the out file?

    help me with this

    Thank you

     

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited October 2018

    Additionally, you can request under OUTPUT> HGEFFMASS to write out the *.mass,*mass.mvw session files which can be directly loaded in HyperGraph to visualize the bar charts detailing on the effective mass output.

    Please also try output results in punch format and open the .pch file. Files attached for your reference.

    <?xml version="1.0" encoding="UTF-8"?>HGEFFMASS.JPG

    Unable to find an attachment - read this blog

  • LOKESH KATARI
    LOKESH KATARI Altair Community Member
    edited October 2018

    sir modal effective mass and mass effective are same ?

     

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited October 2018

    Please refer attached document from help.

    Unable to find an attachment - read this blog