Learning Forum

[sara_hamouni]

Hello everyone

I am trying to reduce a modal base of 1200 modes using the participation factor but I don't know how to choose the significant value. Is there a method to determine this value on ANSYS APDL?

/solu

antype, MODAL, RESTART

mxpand,,,, yes,1e-5,, EFFM                    ! Mode selection is based on the participation factor,

modseloption, yes,no,yes, no,no,no     ! Only direction X and Z is selected,

solve

finish

Here I put 1e-5 as an example

thanks in advance

[1shan]

If the ModSelMethod =EFFM, the significance level of a mode is defined as the modal effective mass, divided by the total mass. Any mode whose significance level is less than this value is considered insignificant and is not expanded. The higher thesignificancethreshold, the fewer the number of modes expanded.The significance value defaults to 0.001 (which should work in most cases) , except for the case of DDAM mode selection method where it defaults to 0.01. Do check out this useful link https://www.youtube.com/watch?v=TO0gD-GpTfU which gives some insight on how to choose the number of modes using participation factor and effective mass.
Regards Ishan.