NORMAL MODES ANALYSIS ON A THIN BODY STEEL STACK

[Anonymous]

Hello,
Did a normal modes analysis on a thin stack
The analysis completes and i get my fundamental frequencies
However, the effective modal mass and the percent effective modal mass are all zero in the output file
Am i doing something wrong

[shigeaki.k · Accepted solution]

Hello @Anonymous,

I just ran a simple modal analysis/normal modes analysis of a part that is fully fixed at one surface, and obtained the below results in the *.out file.  

P E R C E N T M O D A L M A S S
DIRECTION      TOTAL                    MODAL          PERCENT
1                       3.032303E-02   2.687786E-02    88.6384
2                       3.032303E-02   2.443172E-02     80.5715
3                       3.032303E-02   2.769778E-02     91.3424
4                       2.547213E+03   2.545570E+03     99.9355
5                       3.805188E+01   3.428628E+01     90.1041
6                        2.547217E+03   2.544423E+03     99.8903

Do you also have the plots of "Tx effective mass versus mode number" (where x is a number) under "XY Plot"?

Are there any steps you are doing different from the tutorial steps described here?

Could you also check that the parameter MODEPFACTOR is "ON"?

Could you check your material properties such as density etc.?

Regards,

Shigeaki K.