modal analysis -reduced -fluid80

rengg

Hi,
i have been modeling tank filled with water for modal analysis in ansys.
fluid is modeled by fluid80 and tank by shell 63.
i have used reduced method as it is the only acceptable method.
i am getting very high values for mass participating in each direction which is much greater than the total mass.

units are consistent.
the mass calculated by ansys comes out to be correct

please suggest any thing that i may be missing.

regards
ritu

minger

I was going to suggest that you post to XANSYS, but I see that you already have. I would wait for the guys over there to help you out. I could have sworn that I've seen a post about that.

I know that you said your units are consistent, but if I had to stab, the only thing I could think of was checking your ACEL.

sagardude113

@rengg
i'm working on the same problem you see, it's my thesis "fluid structure interaction in liquid storage tanks for base excitation using ANSYS"
so far i too got same problem but if we only model fluid alone and give constraints then the excited mass matches to the theoritical one. The mass excited is more has a reason in selecting the master nodes you see, to which even i'm stuck. but in any way if you'd find the solution to it please it's my hmble request that share the information with me too..
Thanks in anticipation,
Sagar.