Dynamic Stiffness

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello All,

 

can any one tell me how to calculate dynamic stiffness of structure or any component?

which analysis i should carry out?

 

Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Rahul K,

     

    Run a FRF analysis.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hello All,

    can any one tell me mathematical formulation for structural analysis. static and modal

     

     

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited November 2020

    Hi,

     

    Refer attached Pdf.

     

    Regards

    Rahul R

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    thank you sir.

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    dear sir ,

     in that pdf only they mentioned the cards for nastran and there is no mathematical formulas to calculate static analysis

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    Optistruct & Nastran cards are almost similar.I have shared Optistruct user guide in which governing equation are available.

    In some of the FEA books you would get formulation of stiffness matrix for different type of analysis.See attached screenshot for static analysis of rod element from practical finite eleement analysis book written by Mr Nitin Gokhale.

     

    Regards

    Rahul R

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    thank you sir.

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    dear sir ,

     for modal analysis is there any formula apart from  wn2=k/m?

     

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited February 2016

    See attached screenshot.Refer same pdf which i shared earlier for more info.

     

    Regards

    Rahul R

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

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Prakash and Rahul,

    I have done Modal frequency response analysis by giving Displacement as a input and force as a output.

    Now my question is, How to calculate Dynamic stiffness of component?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Rahul,

    The dynamic stiffness is the frequency dependent ratio between a dynamic force and the resulting dynamic displacement.

     

    You can post-process the same using HyperGraph. Since you are a commercial customer, I would suggest to get in touch with INDIA support team.

     

    we suggest you contactcommercial support hotline by phone etc. here - Commercial Support contact

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Dear Prakash,

    Thank you for the vital information.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    dear sir

     nvh analysis means modal frequency response analysis?

     i have intervw on nvh analysis can any one share dat file and give me some datas to learn on that