direct freq resp and modal frq response

Altair Forum User

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I did direct freq resp and modal frq response analysis for same model with same BCs except addition of EIGRL card

I expected to get same output ,but Peaks are are not matching with each other

Could  anyone explain why is that happening ??  

 

Blue curve is Modal freq and the other curve is Direct Freq

 

Thanks

 

 

Altair Forum User

Hi,

 

Can you check your frequency range on Eigrl card which should generally be higher than your frequency of interest (in your case 1000).