Frequency Response Analysis

Altair Forum User

I am new to frequnecy response analysis and have some queries regrding the same

1. I referred the OS- 1300 module for frquency response and I am not sure about how the values of COUPMASS and WTMASS was taken.

2. I want to apply the base excitation of 1g to my model. How can I do that?

3. In the tutorial the DAREA is applied and dof3 is given value of 20. Does that mean the application of frequnecy with amplitude 20?

4. How can I give the damping of 1% to my system?

Thank You.

Altair Forum User

Hi Khushal,

1. I referred the OS- 1300 module for frquency response and I am not sure about how the values of COUPMASS and WTMASS was taken.

COUPMASS refer to using of couplled mass matrix approach for eigenvalue analysis. If yes, Coupled mass matrix will be used. WTMASS is a factor which convets weight to mass

PARAM WTMASS has to be used only if you have convert weight in to mass density

 

2. I want to apply the base excitation of 1g to my model. How can I do that?

You can apply enforced acceleration using SPCD and referring the same in RLOAD1 card. 

3. In the tutorial the DAREA is applied and dof3 is given value of 20. Does that mean the application of frequnecy with amplitude 20?

Yes, a load of 20 is applied at a frequency provided in TABLED1

4. How can I give the damping of 1% to my system?

 

If you want to apply a uniform structural damping, use PARAM>>G as specified in tutorial.