Modal Analysis

Parthiban B
Parthiban B Altair Community Member
edited June 18 in Community Q&A

Hi everyone, 

 

While Performing modal analysis, I Gave RHO(Density) value in 7.8 x 10^-6(Kg/mm3) for steel material, I got some Modal frequency.



But, If same given in tone/mm3 ( 7.8 x 10^-9) I got some other frequency. Yeah it is obvious that natural frequency is a function of mass matrix but I am confused which to use?

image

Best Answer

  • Rajashri_Saha
    Rajashri_Saha
    Altair Employee
    edited June 18 Answer ✓

    Hi Parthiban,

    As you are using E=200000MPA, then you can go for density as 7.8e-9 ton/mm3.

    You can refer the below consistent unit system.

    image

    As you can see for 7.8e-6 density value, E value should be 210GPA or 0.21mN/mm2.

    Hope this answers your query.

    Thanks

    Rajashri

Answers

  • Parthiban B
    Parthiban B Altair Community Member
    edited June 17

    My Elastic modulus value is 200000 MPa (200 GPa)

  • Rajashri_Saha
    Rajashri_Saha
    Altair Employee
    edited June 18 Answer ✓

    Hi Parthiban,

    As you are using E=200000MPA, then you can go for density as 7.8e-9 ton/mm3.

    You can refer the below consistent unit system.

    image

    As you can see for 7.8e-6 density value, E value should be 210GPA or 0.21mN/mm2.

    Hope this answers your query.

    Thanks

    Rajashri

  • Parthiban B
    Parthiban B Altair Community Member
    edited June 17

    Hi Parthiban,

    As you are using E=200000MPA, then you can go for density as 7.8e-9 ton/mm3.

    You can refer the below consistent unit system.

    image

    As you can see for 7.8e-6 density value, E value should be 210GPA or 0.21mN/mm2.

    Hope this answers your query.

    Thanks

    Rajashri

    Thanks Rajashri, 

  • Rajashri_Saha
    Rajashri_Saha
    Altair Employee
    edited June 17

    Thanks Rajashri, 

    Hi Parthiban,

    You can mark the queries as resolved where you got the correct answers.

    You can look into the previous queries and mark them as resolved too.

    That will be helpful for us.

    Thanks

    Rajashri