Learning Forum

[Dennis Chen]

Hello, in using define_SPH_Injection_(option), how can I properly define contact between generated SPH particle and the FEA body?

There's no clear indication of the set being generated, I tied using part ID but no luck/crash.

I appreciate the advice

Thank you! 

[ErKo]

 

 

 

 

 

 

 

 

 

Hello Dennis

 

Not sure exactly what you are after but if it is just the contact between SPH and solid Lagrange bodies then see this (sure you know this):

LSDYNA Bird — Welcome to LS-DYNA Examples

This is used also when using DEFINE_SPH_INJECTION -> in the contact use the PID defined in DEFINE_SPH_INJECTION (PID of new SPH) as SURFA and PART_SET or PART of solids in SURFB – see examples above.

example:

 

*DEFINE_SPH_INJECTION
$#     pid      nsid       cid        vx        vy        vz      area      vmag
         1     

*CONTACT_AUTOMATIC_NODES_TO_SURFACE_MPP_ID
$#     cid                                                                 title
         1                                                                      
$#  ignore      bckt    lcbckt    ns2trk   inititr    parmax    unused    cparm8
         0         1         0         0         0       0.0                   0
$#   surfa     surfb  surfatyp  surfbtyp   saboxid   sbboxid      sapr      sbpr
         1         2         3         3         0         0         0         0

---
Doubt this but to be complete:

 

If you refer to *DEFINE_ADAPTIVE_SOLID_TO_SPH


Say:

CPL	IOPT	Bonding/Connection
0	Any	Not bonded; acts as debris
1	0	Bonded from simulation start
1	1	Bonded after element failure

 

Now if you use the 1st 0 0 opt. above (debris) you can then set the debris interaction via a contact card (say node to surface) and use there SSID and SSTYP=3 to reference the SPH part defined by IPSPH in the *define_ada_solid_sph. So use perhaps a *CONTACT_AUTOMATIC_SINGLE_SURFACE might do the same here (between debris and other surfaces) or even better

 

 

 

*CONTACT_AUTOMATIC_NODES_TO_SURFACE

 

 

 

.

Hope this helps

Since I assume you are supported (saw a case from 2026), search in the ACSS Knowledge base for articles for anything else you would like to know – also AnsysGPT is a good place to search for any other questions –
finally if you are not getting any useful answers with any of those please create a ticket and we will be happy to help you.

Erko

 

 

 

 

 

 

 

 

 

[Dennis Chen]

Hello ErKo, thank you very much for your detailed answer.   I tried using the standard automatic_nodes_to_surface contact and using the pid of the define_SPH_injection but it didn't seem to work.   I will give this more try this weekend perhaps by starting with something simpler to see if I can get the contact to work.   

I am trying to replicate the pouch injection paper outlined here - https://www.dynalook.com/conferences/14th-european-ls-dyna-conference-2023/simulation-methods/novozhilov_cadfem.pdf.   

This method can also be extended to a sink damping problem where the we may want to model the fluid being dispensed from the faucet into the sink and measure vibration of the sink before and after a damping tape layer is applied to reduce noise from the sink.   That would be the real industry application for this. 

Again, thank you! :)

[ErKo]

 

Happy to help.

I did a simple example and it works as we discussed.

This is used also when using DEFINE_SPH_INJECTION -> in the contact use the PID defined in DEFINE_SPH_INJECTION (PID of new SPH) as SURFA and PART_SET or PART of solids in SURFB – see examples above.

example:

 

*DEFINE_SPH_INJECTION
$#     pid      nsid       cid        vx        vy        vz      area      vmag
         1     

*CONTACT_AUTOMATIC_NODES_TO_SURFACE_MPP_ID
$#     cid                                                                 title
         1                                                                      
$#  ignore      bckt    lcbckt    ns2trk   inititr    parmax    unused    cparm8
         0         1         0         0         0       0.0                   0
$#   surfa     surfb  surfatyp  surfbtyp   saboxid   sbboxid      sapr      sbpr
         1         2         3         3         0         0         0         0

They interact with the plate as shown:


All the best

Erko