Learning Forum

[amirhossein.nikpour]

Hello,

I am currently modeling a water-filled vessel in LS-DYNA. 

The vessel structure is modeled using shell elements, and the water is modeled using SPH particles.  The vessel is subjected to earthquake records. 

The adopted dimensions are ton-mm-s-N

 

The issue I am encountering is that the water appears to compress excessively ( please see the video)

 

EOS_MURNAGHAN

K=2200 

GAMMA= 7

 

SPH SECTION

CSLH 1.2

HMIN 1 

HMAX 1.1

 

SPH CONTROL

IDIM 1

NMMNEIGH 250

FORM 15

MAXV 0

 

BODY LOAD Y WITH DR

 

Sph mass 17.3 ton

Sph particle mass 0.0032 ton

Number of sph particle 5409

 

Sph material 

09- NULL

RO 1.000e-09 

MU=0

 

Automatic node surface contact

SFSA= 2

FSSB= 1

SOFT= 1

SOFSC= 0.1

 

 

I would appreciate it if you could share your recommendations on how to resolve this issue.

Thank you in advance for your support.

[ErKo]

 

 

 

 

Hi

I think SPH is not going to be very good/easy for this (pressure distribution is hard to get right even for just static water – so even hydrostatic pressure can be very hard) – others might comment here.

Perhaps I would suggest ALE or ICFD aproaches instead – there are some papers on these 2 if you search online (sure you know about this one) . E.g.:

Analytical and Numerical Studies of Seismic Fluid-Structure Interaction in Liquid-Filled Vessels

 

Perhaps other members might have some experience with this type of analysis, so wait for feedback – hope this helps

Erko