Could someone tell me why they build a SPH layer at the bottom?
This is an example of dam break from https://www.dynaexamples.com/sph/intermediate-examples/wavestructure
The presence of downstream particles influences the wave profile, for dam-break waves there are typically two types of simulations, a dry-bed and a wet-bed simulation. Furthermore, this example is based on a SPH validation method termed a "bore-in-a-box" simulation, you can see the model domain and details in the paper they outline on the example page.
It does not matter is the column sticks a little lower than the bottom surface. It is conservative to have it lower rather than higher.
As for contact, maybe you may first try with something like:
$# dtinit tssfac isdo tslimt dt2ms lctm erode ms1st
0.0 0.45 0 0.0 0.0 0 0 0
$# cid title
1SPH to Column
$# ignore bucket lcbucket ns2track inititer parmax unused cparm8
0 1 0 3 2 1.0005 0
$# ssid msid sstyp mstyp sboxid mboxid spr mpr
2 1 3 3 0 0 0 0
$# fs fd dc vc vdc penchk bt dt
0.0 0.0 0.0 0.0 0.0 0 0.01.00000E20
$# sfs sfm sst mst sfst sfmt fsf vsf
0.0 0.5 0.0 0.0 1.0 1.0 1.0 1.0
$# soft sofscl lcidab maxpar sbopt depth bsort frcfrq
1 0.1 0 1.025 2.0 2 50 1
Else, try these additionally, one at a time or combination:
- PENMAX=1000 in the option card B of *CONTACT_ keyword-
- XPENE=1000 in *CONTROL_CONTACT keyword
- try SOFT=1 and set SFS = SFM = 1.0e-12 in *CONTACT_AUTOMATIC_NODES_TO_SURFACE
- SOFSCL=1.0 (increase from 0.1 default if contact leaks, maybe for very high velocity impact or explosion)
Thank you so much for your kind suggestions. My issues have been addressed.😀
Thank you very much for yor response. Another detail is that the bottom of the pillar is lower than the bottom rigid wall. Is it necessary?
I modified this model by changing the shape of obstacle and size of the whole model, however, some unreasonable results occurs. Particles penetrated the obstacle and no interaction occurs(CONTACT_AUTOMATIC_NODES_TO_SURFACE is used to define the interaction between particles and FEM obstacle). Furthermore, particles moves upwards along the left wall. Could you tell me how to handle the penetration?
Hi all, I have a new issue in this simulation. After the water droped down, there are some particles move upwards along the left rigidwall. It is like those particles adhere to the wall. I have tried to reduce the gap between wall and water, but doesn't work. Could you help me to resolve this?
The rigidwall must align the part surface. When change the particle spacing, small gap may generated between the rigidwall and part surface, thus the contact between rigidwall and part produced weird results. If particle spacing is changed, the rigidwall must be updated.
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