CommunityHi all.
I also simulate rock drilling using SPH particles.
I use the increased density to speed up the solution to the problem. Increasing the density for SPH is not recommended, but I did such tests, I also do tests without increasing the density, they have not yet completed. But I have questions.
The task is similar to LSTC
https://www.lstc-cmmg.org/drilling
Only I use the rock and my feed and drilling speeds. I use an average speed of 25 m/s feed speed and 27 rad/s drilling speed. While solving the problem, I encountered several problems.
1. Particles scatter wildly. And when the particles fly apart, they pull the solid ring behind them and it is greatly distorted:
2.I reduced the density a little, the solution became better and I got good stress. I also replaced the EROSION contact with AUTOMATIC:
But the particles still fly away strongly and do not break off in large pieces. Why? how to deal with this? It happens like this: the drill pierces the particles, they begin to fly away more and more until the end of the calculation time.
I use concrete material JHC
Hi all.
I'm simulating rock drilling using SPG particles.
I use the increased density to speed up the solution to the problem.
The task is similar to LSTC
https://www.lstc-cmmg.org/drilling
Only I use the rock and my feed and drilling speeds.
I use an average speed of 25 m/s feed speed and 27 rad/s drilling speed.
While solving the problem, I encountered several problems.
1.I get a negative volume error. And when the particles fly apart, they pull the solid ring behind them and it is greatly distorted:
At low feed speeds there are no such problems.
2.I reduced the density a little, the solution became better and I got good stress. I also replaced the EROSION contact with AUTOMATIC:
But now I get warnings:
Why? how to deal with this?
Dear all,
I am using an Autodyn subroutine for a project and the simulation stops at cycle 99,999, see the image below.
What I do not understand is that the criteria that could limit the number of cycles is much more important than 100,000:
- Controls > Wrapup Criteria: >100,000;
- Output > Interrupt: End cycle = 100,000,000;
- Output > Call EXEDIT: End cycle = 100,000,000;
In addition, the subroutine usrsub2.f90 calls the "WRAPUP" module but does not redefine it, so there is no arbitrary "NCYLIM" defined in the subroutine. Do you know where this limitation might come from?
Thank you in advance for your help,
Audrey
Hi!
I was trying to make shear waves in Ansys Explicit Dynamics. I am not sure what to do, and wants to listen to all suggestions. My initial plan was to make a box (5x5x10mm), and do something with (one/ some of) the nodes to make a shear wave propagating throughout the "box" by time.
This is my box so far:
Any suggestions?
i was trying to solve example of SPR which is in LS-Dyna example site.
https://www.dynaexamples.com/introduction/process_simulation/self-piercing-riveting
my status doesnt go further but in LS-run status is still running (cpu usage is amlost none at this moment)
message is end just like this
'Cutting plane= 3053 3056 0.80254E-01'
i cant solve whole simulation because of this problem
how can i solve this example????
I want to see the stress variation over time at a specific point in LS dyna. Its a 3d model and ive attempted to use a stress probe with no luck so far. Any help would be appriecated!
Hello,
I'm using SPH to simulate a high-velocity impact problem.
The material type I used is MAT 15, whose history variable 5 is the temperature change. Now I would like to output all the temperature changes for all the SPH nodes in one part and it will take a very long time to read the result file and output the plot due to a large number of SPH nodes used. So, I would like to know whether it is possible to output all the element temperatures of the part when setting the keyword DATABASE. I've checked the manual but I cannot find which keyword to use.
For instance, the nodal information can be output as nodout file and the energy information can be output as matsum.
I used Lsdyna for vibration analysis and imported the response file into Virtual .Lab for noise analysis, but Virtual .Lab only supports rst files. So I need to convert the LSDYNA result file to rst file
Hi everyone,
I am trying to make a prestress bird strike analysis. In prestress (Static Structural) i have thermal, pressure and bolt preload loads. I am using SPH particle method to model bird, however, static structural doesn't support that. I couldn't find any way to solve it yet. Do you know how can constrain the SPH bird in static structural module? Or how can map the stresses which comes from WB Static structural to LS Dyna Explicit model ?
Regards.
I am creating an additive manufactured Model with Iherent strain, LPBF function in Ansys and have created the model to study the residual stress.
How can I import the model in LS Dyna for further research?
Thanks!
Hi,
When I observed the information of a cross-section using the section plane in LSPP, sometimes, some blank spots were observed. it seems that some elements at the selected cross-section are gone. I set the scale of displacement as zero. What are the potential causes? Thank you!
Kind regards,
Chayir
I have a thesis project using LS-DYNA 2023. I am attempting to use a single point of reference on a 3d solid plate and see the stress of it over time (cannot select surface). I have tried using named selections and coordinate system to highlight the point i want with no success. I have done similar things with fluent before but cannot seem to make this work. Sorry if my explaining is bad
Hi all.
A very strange situation. Previously I used a rigid body and set the translation and rotation using RIGID_BODY_MOTION. I made the body deformable and now set the rotation and translation using MOTION_SET. But rotation does not occur. The calculation gives an error, despite the fact that I have specified nodes for rotation
I am trying to save the nodal forces of a DYNA simulation and can't get the NODFOR file to generate. My card deck is below. Does anyone know what is going on here? Thanks!
$ LS-DYNA Keyword file created by fem.dyna Python functions
$ Created on 05:53PM on July 24, 2023
*KEYWORD
*CONTROL_ENERGY
$ hgen, rwen, slnten, rylen
2,2,2,2
*CONTROL_MPP_IO_NOFULL
*CONTROL_TERMINATION
$ endtim, endcyc, dtmin, endeng, endmas
0.0045,0,0.0,0.0,0.0
*CONTROL_TIMESTEP
$ dtinit, tssfac, isdo, tslimt, dt2ms, lctm, erode, ms1st
1e-06,0.02,0,0.0,0.0,1,0,0
*DATABASE_NODOUT
$ dt, binary, lcur, ioopt, option1, option2
2e-05,0,0,1,0.0,0
*DATABASE_NODFOR
$ dt, binary, lcur, ioopt, option1, option2
1e-06,0,0,1,0.0,0
*DATABASE_EXTENT_BINARY
$ neiph, neips, maxint, strflg, sigflg, epsflg, rltflg, engflg
0,0,3,0,2,2,2,1
$ cmpflg, ieverp, beamip, dcomp, shge, stssz, n3thdt, ialemat
0,0,0,4,1,1,2,0
*DATABASE_FORMAT
$ iform, ibinary
0,1
*DATABASE_HISTORY_NODE_SET
$ id1, id2, id3, id4, id5, id6, id7, id8
1,0,0,0,0,0,0,0
*SET_NODE_GENERAL
1
ALL
*PART
$ Title
background
$ pid, secid, mid, eosid, hgid, grav, adpopt, tmid
1,1,1,0,0,0,0,0
*SECTION_SOLID
$ secid, elform, aet
1,2,0
*PART
$ Title
background pml
$ pid, secid, mid, eosid, hgid, grav, adpopt, tmid
2,2,2,0,0,0,0,0
*SECTION_SOLID
$ secid, elform, aet
2,2,0
*INCLUDE
../../nodes.dyn
*INCLUDE
../../elems.dyn
*INCLUDE
../NodalLoads.dyn
*INCLUDE
Materials.dyn
*INCLUDE
LoadCurves.dyn
*END
Hello,
I am simulating the deformation of a metallic tube in the low velocity range.
Unfortunately, large distortions occur at the shell elements (see figure).
These stretch to infinity and the voltage drops to 0.
These distortions occur during self-contact.
Attempts to counteract this by applying Hourglass were not really successful.
A short excerpt from the K-File:
*CONTROL_HOURGLASS
$# ihq qh
8 0.03
*CONTROL_SHELL
$# wrpang esort irnxx istupd theory bwc miter proj
20.0 1 -1 0 16 2 1 0
$# rotascl intgrd lamsht cstyp6 thshel
1.0 0 0 1 0
*CONTACT_AUTOMATIC_SINGLE_SURFACE_ID
$# cid title
1Self_Contact
$# surfa surfb surfatyp surfbtyp saboxid sbboxid sapr sbpr
13 0 3 0 0 0 0 0
$# fs fd dc vc vdc penchk bt dt
0.2 0.18 0.0 0.0 5.0 0 0.01.00000E20
$# sfsa sfsb sast sbst sfsat sfsbt fsf vsf
2.0 1.0 0.0 0.0 1.0 1.0 1.0 1.0
$# soft sofscl lcidab maxpar sbopt depth bsort frcfrq
1 0.2 0 1.025 3.0 2 100 1
$# penmax thkopt shlthk snlog isym i2d3d sldthk sldstf
0.0 1 2 0 0 0 0.0 0.0
$# igap ignore dprfac dtstif edgek unused flangl cid_rcf
1 0 0.0 0.0 0.0 0.0 0
*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_ID
$# cid title
2dropmass
$# surfa surfb surfatyp surfbtyp saboxid sbboxid sapr sbpr
13 10 3 3 0 0 2 0
$# fs fd dc vc vdc penchk bt dt
0.2 0.18 0.0 0.0 0 0.01.00000E20
$# sfsa sfsb sast sbst sfsat sfsbt fsf vsf
1.0 1.0 0.0 1.0 1.0 1.0 1.0
$# soft sofscl lcidab maxpar sbopt depth bsort frcfrq
2 0.1 0 1.025 1.0 2 10 1
$# penmax thkopt shlthk snlog isym i2d3d sldthk sldstf
0.0 0 0 0 0 0 0.0 0.0
$# igap ignore dprfac dtstif edgek unused flangl cid_rcf
1 0 0.0 0.0 0.0 0.0 0
*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_ID
$# cid title
3bottom
$# surfa surfb surfatyp surfbtyp saboxid sbboxid sapr sbpr
13 11 3 3 0 0 0 0
$# fs fd dc vc vdc penchk bt dt
0.2 0.18 0.0 0.0 0 0.01.00000E20
$# sfsa sfsb sast sbst sfsat sfsbt fsf vsf
1.0 1.0 0.0 1.0 1.0 1.0 1.0
$# soft sofscl lcidab maxpar sbopt depth bsort frcfrq
2 0.1 0 1.025 1.0 2 10 1
$# penmax thkopt shlthk snlog isym i2d3d sldthk sldstf
0.0 0 0 0 0 0 0.0 0.0
$# igap ignore dprfac dtstif edgek unused flangl cid_rcf
1 0 0.0 0.0 0.0 0.0 0
Maybe someone has an idea why this happens?
I'd like to plot Number of Eroded Elements vs Time in LSPP. Is this possible?
Hello,
There is an issue of the Ls-dyna SPH simulation. When I use the solver on my University HPC to do a SPH simulation, the d3plot cannot fully generated. The total set steps are about 102 d3plots for normal termination, while after generating about 80 d3plots, the solver got stuck and the task reported an error after running out of time. However, when I use the LS-Run on my Windows desktop, the job could end normally. The solver version on the HPC is R 10.1 and the local solver on my desktop is R 13.0. I’m not sure whether the solver version led to that issue.
The message file for the failed job:
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Date: 09/19/2023 Time: 15:42:25
___________________________________________________
| |
| LS-DYNA, A Program for Nonlinear Dynamic |
| Analysis of Structures in Three Dimensions |
| Date : 11/15/2022 Time: 13:48:14 |
| Version : smp s R13 |
| Revision: R13.1.1-13-g5480eca294 |
| |
| Features enabled in this version: |
| Shared Memory Parallel |
| FFTW (multi-dimensional FFTW Library) |
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| ANSYSLIC enabled |
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| Hostname : ENGR6321 |
| Precision : Single precision (I4R4) |
| |
| Unauthorized use infringes Ansys Inc. copyrights |
|___________________________________________________|
Command line options: i=C:\Users\rji229\Documents\fem_sph_circular\Test\1\Run.k
ncpu=1
memory=97m
Input file: C:\Users\rji229\Documents\fem_sph_circular\Test\1\Run.k
The native file format : 32-bit small endian
Memory size from command line: 97000000
allocating memory to 97000000 d 544 Initial allocation
******** notice ******** notice ******** notice ********
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* This is the LS-DYNA Finite Element code. *
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* the validity, accuracy, or applicability of any results *
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* accurate and easy to use as possible. *
* Suggestions and comments are welcomed. Please report any *
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* immediately to LST through your site focus. *
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* Copyright (C) 1990-2022 *
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******** notice ******** notice ******** notice ********
Beginning of keyword reader 09/19/23 15:42:25
expanding memory to 20720 d 600
expanding memory to 66080 d 2212719
expanding memory to 98580 d 2212719
expanding memory to 1578326 d 2272719
expanding memory to 1606836 d 2272719
expanding memory to 1629036 d 2280719
expanding memory to 1744036 d 2280719
09/19/23 15:42:25
Open include file: SPH_Ball_15x15x15.k
09/19/23 15:42:25
Open include file: SPH_Plate_90x90x30.k
09/19/23 15:42:25
Open include file: MatFile_Y5_PA.k
expanding memory to 1765932 d 2280719
expanding memory to 2012200 d 5465002
expanding memory to 2256992 d 5465002
Memory required to process keyword : 2256992
Additional dynamic memory required : 8647293
contracting memory to 1 d 5465008 end of keyword reader
LS-DYNA will perform a structural only analysis
Y5_PA_HV
ls-dyna smp s R13 R13.1.1_13_5480ec date 11/15/2022
expanding memory to 2001 d 1445 material, node and element data
expanding memory to 2071 d 1475 material properties
expanding memory to 2085 d 8324474 gradient of damage data
expanding memory to 2107 d 8324529 user control for contact interfaces
contracting memory to 2087 d 8324531 thermal expansion 0
expanding memory to 2089 d 8324533 cross-sectional force definitions 0
expanding memory to 246880 d 8324547 temp index array for node sorting
contracting memory to 2089 d 8569342 just because?
expanding memory to 4091 d 10283422 load curve data
contracting memory to 2097 d 10283422 user_define_loading_set
expanding memory to 2297 d 10283422 regularize time history data
contracting memory to 2101 d 10283422 *DEFINE_ELEMENT_DEATH
expanding memory to 492683 d 10528238 implicit contact 1
contracting memory to 3101 d 10528344 contact segment data 1
expanding memory to 1227056 d 10528344 contact segment data 3
contracting memory to 2101 d 14740307 contact definition
expanding memory to 2105 d 14740978 contact friction
expanding memory to 1715702 d 37752065 SPH elements
expanding memory to 1715802 d 38241723 rigid bodies for disp. termination
expanding memory to 1715872 d 38241723 save d3plot control data
S t o r a g e a l l o c a t i o n
Memory required to begin solution : 2257K
Additional dynamically allocated memory: 41M
Total: 43M
1 t 0.0000E+00 dt 1.10E-12 flush i/o buffers 09/19/23 15:42:33
1 t 0.0000E+00 dt 1.10E-12 write d3plot file 09/19/23 15:42:33
96 t 9.4113E-08 dt 9.41E-09 write d3plot file 09/19/23 15:43:22
103 t 1.8341E-07 dt 1.83E-08 write d3plot file 09/19/23 15:43:25
108 t 2.9539E-07 dt 2.95E-08 write d3plot file 09/19/23 15:43:28
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 3.9317E-07, ncycle = 110
111 t 3.9317E-07 dt 3.66E-08 write d3plot file 09/19/23 15:43:30
113 t 4.6671E-07 dt 3.96E-08 write d3plot file 09/19/23 15:43:31
116 t 5.9188E-07 dt 3.95E-08 write d3plot file 09/19/23 15:43:33
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 6.3133E-07, ncycle = 116
118 t 6.7157E-07 dt 4.11E-08 write d3plot file 09/19/23 15:43:34
121 t 7.9410E-07 dt 4.17E-08 write d3plot file 09/19/23 15:43:37
123 t 8.8038E-07 dt 4.54E-08 write d3plot file 09/19/23 15:43:38
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 9.2573E-07, ncycle = 123
125 t 9.6982E-07 dt 4.65E-08 write d3plot file 09/19/23 15:43:40
127 t 1.0610E-06 dt 4.36E-08 write d3plot file 09/19/23 15:43:42
130 t 1.1918E-06 dt 4.53E-08 write d3plot file 09/19/23 15:43:44
132 t 1.2849E-06 dt 4.77E-08 write d3plot file 09/19/23 15:43:46
134 t 1.3799E-06 dt 4.74E-08 write d3plot file 09/19/23 15:43:48
136 t 1.4746E-06 dt 4.63E-08 write d3plot file 09/19/23 15:43:50
138 t 1.5663E-06 dt 4.43E-08 write d3plot file 09/19/23 15:43:51
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 1.6532E-06, ncycle = 139
140 t 1.6532E-06 dt 4.69E-08 write d3plot file 09/19/23 15:43:53
143 t 1.7969E-06 dt 4.83E-08 write d3plot file 09/19/23 15:43:56
145 t 1.8806E-06 dt 3.90E-08 write d3plot file 09/19/23 15:43:57
147 t 1.9626E-06 dt 4.46E-08 write d3plot file 09/19/23 15:43:59
150 t 2.0788E-06 dt 3.60E-08 write d3plot file 09/19/23 15:44:02
153 t 2.1979E-06 dt 4.44E-08 write d3plot file 09/19/23 15:44:05
155 t 2.2817E-06 dt 3.75E-08 write d3plot file 09/19/23 15:44:06
158 t 2.3922E-06 dt 3.80E-08 write d3plot file 09/19/23 15:44:09
160 t 2.4720E-06 dt 4.60E-08 write d3plot file 09/19/23 15:44:11
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 2.5625E-06, ncycle = 161
162 t 2.5625E-06 dt 3.95E-08 write d3plot file 09/19/23 15:44:13
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 2.6020E-06, ncycle = 162
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 2.6867E-06, ncycle = 164
165 t 2.6867E-06 dt 4.71E-08 write d3plot file 09/19/23 15:44:15
167 t 2.7825E-06 dt 4.80E-08 write d3plot file 09/19/23 15:44:17
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 2.8306E-06, ncycle = 167
169 t 2.8726E-06 dt 3.94E-08 write d3plot file 09/19/23 15:44:19
171 t 2.9541E-06 dt 4.63E-08 write d3plot file 09/19/23 15:44:21
174 t 3.0939E-06 dt 4.62E-08 write d3plot file 09/19/23 15:44:24
176 t 3.1808E-06 dt 4.38E-08 write d3plot file 09/19/23 15:44:26
178 t 3.2728E-06 dt 4.89E-08 write d3plot file 09/19/23 15:44:28
180 t 3.3658E-06 dt 4.24E-08 write d3plot file 09/19/23 15:44:30
183 t 3.4967E-06 dt 4.81E-08 write d3plot file 09/19/23 15:44:33
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 3.5926E-06, ncycle = 184
185 t 3.5926E-06 dt 4.22E-08 write d3plot file 09/19/23 15:44:35
187 t 3.6749E-06 dt 4.20E-08 write d3plot file 09/19/23 15:44:37
189 t 3.7631E-06 dt 4.85E-08 write d3plot file 09/19/23 15:44:39
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 3.8117E-06, ncycle = 189
191 t 3.8592E-06 dt 4.25E-08 write d3plot file 09/19/23 15:44:41
194 t 3.9923E-06 dt 4.82E-08 write d3plot file 09/19/23 15:44:43
196 t 4.0878E-06 dt 4.72E-08 write d3plot file 09/19/23 15:44:45
198 t 4.1826E-06 dt 4.38E-08 write d3plot file 09/19/23 15:44:47
200 t 4.2747E-06 dt 4.86E-08 write d3plot file 09/19/23 15:44:49
202 t 4.3722E-06 dt 4.90E-08 write d3plot file 09/19/23 15:44:51
204 t 4.4688E-06 dt 4.47E-08 write d3plot file 09/19/23 15:44:53
206 t 4.5568E-06 dt 4.54E-08 write d3plot file 09/19/23 15:44:55
209 t 4.6991E-06 dt 4.69E-08 write d3plot file 09/19/23 15:44:58
211 t 4.7946E-06 dt 4.44E-08 write d3plot file 09/19/23 15:45:00
213 t 4.8792E-06 dt 4.17E-08 write d3plot file 09/19/23 15:45:01
215 t 4.9669E-06 dt 4.79E-08 write d3plot file 09/19/23 15:45:04
217 t 5.0629E-06 dt 4.76E-08 write d3plot file 09/19/23 15:45:06
220 t 5.1926E-06 dt 4.49E-08 write d3plot file 09/19/23 15:45:09
222 t 5.2864E-06 dt 4.41E-08 write d3plot file 09/19/23 15:45:11
224 t 5.3770E-06 dt 4.62E-08 write d3plot file 09/19/23 15:45:13
226 t 5.4674E-06 dt 4.83E-08 write d3plot file 09/19/23 15:45:15
228 t 5.5637E-06 dt 4.82E-08 write d3plot file 09/19/23 15:45:17
230 t 5.6554E-06 dt 4.69E-08 write d3plot file 09/19/23 15:45:19
233 t 5.7966E-06 dt 4.41E-08 write d3plot file 09/19/23 15:45:22
235 t 5.8892E-06 dt 4.64E-08 write d3plot file 09/19/23 15:45:24
237 t 5.9818E-06 dt 4.82E-08 write d3plot file 09/19/23 15:45:25
239 t 6.0788E-06 dt 4.88E-08 write d3plot file 09/19/23 15:45:27
241 t 6.1725E-06 dt 4.63E-08 write d3plot file 09/19/23 15:45:28
243 t 6.2657E-06 dt 4.86E-08 write d3plot file 09/19/23 15:45:30
245 t 6.3630E-06 dt 4.79E-08 write d3plot file 09/19/23 15:45:31
247 t 6.4585E-06 dt 4.50E-08 write d3plot file 09/19/23 15:45:33
250 t 6.5981E-06 dt 4.74E-08 write d3plot file 09/19/23 15:45:35
252 t 6.6944E-06 dt 4.91E-08 write d3plot file 09/19/23 15:45:36
254 t 6.7913E-06 dt 4.90E-08 write d3plot file 09/19/23 15:45:38
256 t 6.8895E-06 dt 4.78E-08 write d3plot file 09/19/23 15:45:40
258 t 6.9860E-06 dt 4.74E-08 write d3plot file 09/19/23 15:45:41
260 t 7.0814E-06 dt 4.89E-08 write d3plot file 09/19/23 15:45:43
262 t 7.1792E-06 dt 4.88E-08 write d3plot file 09/19/23 15:45:44
264 t 7.2768E-06 dt 4.78E-08 write d3plot file 09/19/23 15:45:46
266 t 7.3730E-06 dt 4.87E-08 write d3plot file 09/19/23 15:45:47
268 t 7.4703E-06 dt 4.86E-08 write d3plot file 09/19/23 15:45:49
270 t 7.5675E-06 dt 4.86E-08 write d3plot file 09/19/23 15:45:50
272 t 7.6649E-06 dt 4.66E-08 write d3plot file 09/19/23 15:45:52
274 t 7.7580E-06 dt 4.66E-08 write d3plot file 09/19/23 15:45:53
277 t 7.8993E-06 dt 4.65E-08 write d3plot file 09/19/23 15:45:56
279 t 7.9947E-06 dt 4.85E-08 write d3plot file 09/19/23 15:45:57
281 t 8.0890E-06 dt 4.70E-08 write d3plot file 09/19/23 15:45:59
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 8.1844E-06, ncycle = 282
283 t 8.1844E-06 dt 4.86E-08 write d3plot file 09/19/23 15:46:01
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 8.2330E-06, ncycle = 283
285 t 8.2819E-06 dt 4.88E-08 write d3plot file 09/19/23 15:46:02
287 t 8.3787E-06 dt 4.88E-08 write d3plot file 09/19/23 15:46:04
289 t 8.4710E-06 dt 4.78E-08 write d3plot file 09/19/23 15:46:05
291 t 8.5661E-06 dt 4.87E-08 write d3plot file 09/19/23 15:46:07
293 t 8.6636E-06 dt 4.89E-08 write d3plot file 09/19/23 15:46:08
295 t 8.7594E-06 dt 4.79E-08 write d3plot file 09/19/23 15:46:10
297 t 8.8559E-06 dt 4.85E-08 write d3plot file 09/19/23 15:46:11
299 t 8.9530E-06 dt 4.84E-08 write d3plot file 09/19/23 15:46:13
302 t 9.0990E-06 dt 4.87E-08 write d3plot file 09/19/23 15:46:15
304 t 9.1965E-06 dt 4.56E-08 write d3plot file 09/19/23 15:46:17
306 t 9.2881E-06 dt 4.69E-08 write d3plot file 09/19/23 15:46:18
308 t 9.3827E-06 dt 4.90E-08 write d3plot file 09/19/23 15:46:20
310 t 9.4806E-06 dt 4.82E-08 write d3plot file 09/19/23 15:46:21
312 t 9.5729E-06 dt 4.67E-08 write d3plot file 09/19/23 15:46:23
314 t 9.6638E-06 dt 4.66E-08 write d3plot file 09/19/23 15:46:24
316 t 9.7579E-06 dt 4.85E-08 write d3plot file 09/19/23 15:46:26
*** Warning 40042 (SOL+42)
Part ID = 5000001 plasticity algorithm did not converge for MAT15
time = 9.8512E-06, ncycle = 317
319 t 9.8980E-06 dt 4.36E-08 write d3plot file 09/19/23 15:46:28
321 t 9.9851E-06 dt 4.78E-08 write d3plot file 09/19/23 15:46:30
*** termination time reached ***
321 t 1.0033E-05 dt 4.78E-08 write d3dump01 file 09/19/23 15:46:30
321 t 1.0033E-05 dt 4.78E-08 write d3plot file 09/19/23 15:46:30
N o r m a l t e r m i n a t i o n 09/19/23 15:46:30
S t o r a g e a l l o c a t i o n
Memory required to complete solution : 2257K
Additional dynamically allocated memory: 150M
Total: 152M
T i m i n g i n f o r m a t i o n
CPU(seconds) %CPU Clock(seconds) %Clock
----------------------------------------------------------------
Keyword Processing ... 1.0000E+00 0.41 4.9200E-01 0.20
KW Reading ......... 1.0000E+00 0.41 3.3300E-01 0.14
KW Writing ......... 0.0000E+00 0.00 3.1000E-02 0.01
Initialization ....... 8.0000E+00 3.25 8.7360E+00 3.54
Init Proc Phase 1 .. 7.0000E+00 2.85 7.0600E+00 2.86
Init Proc Phase 2 .. 0.0000E+00 0.00 1.9000E-02 0.01
Element processing ... 2.3200E+02 94.31 2.2922E+02 93.01
SPH ................ 2.3200E+02 94.31 2.2922E+02 93.01
Binary databases ..... 5.0000E+00 2.03 7.2970E+00 2.96
ASCII database ....... 0.0000E+00 0.00 2.8000E-02 0.01
Time step size ....... 0.0000E+00 0.00 1.5000E-02 0.01
Others ............... 0.0000E+00 0.00 5.0000E-03 0.00
Misc. 1 .............. 0.0000E+00 0.00 6.8000E-02 0.03
Force to Accel ..... 0.0000E+00 0.00 6.6000E-02 0.03
Misc. 2 .............. 0.0000E+00 0.00 3.7300E-01 0.15
Misc. 3 .............. 0.0000E+00 0.00 1.7500E-01 0.07
Misc. 4 .............. 0.0000E+00 0.00 4.3000E-02 0.02
Timestep Init ...... 0.0000E+00 0.00 4.3000E-02 0.02
----------------------------------------------------------------
T o t a l s 2.4600E+02 100.00 2.4645E+02 100.00
Problem time = 1.0033E-05
Problem cycle = 321
Total CPU time = 246 seconds ( 0 hours 4 minutes 6 seconds)
CPU time per zone cycle = 3016.115 nanoseconds
Clock time per zone cycle= 3018.953 nanoseconds
Number of CPU's 1
NLQ used/max 136/ 136
Start time 09/19/2023 15:42:25
End time 09/19/2023 15:46:30
Elapsed time 245 seconds for 321 cycles using 1 SMP thread
( 0 hour 4 minutes 5 seconds)
N o r m a l t e r m i n a t i o n 09/19/23 15:46:30
Hello,
I am receiving this error when I try to run an model with SPH part
__________
*** Error 30281 (INI+281)
SPH initialization
Material number 5
material type 20 is not implemented
__________
I don't understand this error because material number 5 is not material type 20 in my model.
I would appreciate every suggestion.
Thanks,
Hello,
I have modeled a timber panel in LS-DYNA using *MAT_WOOD. The analysis goes well until a negative volume error terminates the analysis.
I found some information and approaches that can help to overcome negative volumes in the following link:
https://www.dynasupport.com/howtos/material/negative-volume-in-soft-materials
“In materials that undergo extremely large deformations, such as soft foams, an element may become so distorted that the volume of the element is calculated as negative. This may occur without the material reaching a failure criterion. There is an inherent limit to how much deformation a Lagrangian mesh can accommodate without some sort of mesh smoothing or remeshing taking place. A negative volume calculation in LS-DYNA will cause the calculation to terminate unless ERODE in *CONTROL_TIMESTEP is set to 1 and DTMIN in *CONTROL_TERMINATION is set to any nonzero value in which case the offending element is deleted and the calculation continues (in most cases). Even with ERODE and DTMIN set as described, a negative volume may cause an error termination.”
I followed the approaches and set the ERODE=1 and DTMIN= nonzero, however, I understood that the analysis is very sensitive to the value of DTMIN which is a reduction factor for initial time step size to determine minimum time step. When I set it as a number equal to or greater than 1, all elements will be deleted at the beginning of the analysis. When I set it as a value between zero and 0.1 (e.g. DTMIN=0.08), all elements will be deleted at some point at the middle of the analysis. It is also noteworthy that when I set it as a number between 0.1 and one (e.g. DTMIN=0.8), error termination occurs because of out of range velocity of some nodes.
Therefore, I wonder how I can find the proper value for DTMIN so that I can get rid of such a negative volume error. I would appreciate it if you could give me some advice in this regard or any other approaches that can help to overcome negative volumes for my model.
Thanks in advance.
Regards,
Mehdi
I am new to LS-DYNA and have a couple of questions about LS-DYNA and its relation to ANSYS. I want to do a fluid-structure interaction simulation with immersed boundary method. I am confused with the LS-DYNA available in ANSYS workbench. Based on an old user guide (2017) I found, it mentioned that workbench LS-DYNA cannot handle two-way FSI problem. Is this feature included in the new version of Ansys?
If not, is it true that the FSI problem can only be done via LS-RUN? Can I use Ansys product launcher to call LS-DYNA solver to run FSI problem directly?
I am also curious about whether you can use ANSYS-LS-DYNA to do preprocessing. I noticed that you can export k files from workbench setup for solids, can you do that for fluid as well? Can you export user-defined material from Ansys to k file?
Thanks!
I have a simple ball impacting a plate (with some added erosion to simulate a perforation). At a medium sized mesh I get expected results
For the much finer mesh (below; mesh hidden since it is too fine). The ball seems to dimple the surface but then just ghosts right through the plate. Nothing was changed in the problem setup except for mesh size.
I am using AUTOMATIC_SINGLE_SURFACE with SOFT = 1 but this happened with SOFT = 2, also. Presumably this is something to do with the contact stiffness, since all formulations SOFT=0,1,2 have contact stiffness dependent on either the mesh size or the timestep (via, in part, the mesh size). I would have thought this would be handled more robustly for such a simple problem then have to manually tweak contact scale factors...
Perhaps there is an atlernative contact scheme that is more robust? If not, how do I know how much contact stiffness to add to get the same results as the coarse mesh. It is very counter intuitive that a coarse mesh produces better results in this case.
Hi everyone,
I see a lot of discussion of the benefits of using SOFT = 2 over SOFT = 0 or 1 but outside of the added computational complexity are there any obvious downsides to SOFT = 2? I feel like I want to move torwards using it as a default algorithm since my problems are often computationally small. Seems to be robust. Any thoughts on edge cases?
Hello, I want to model fresh concrete as a Bingham/Herschel-Bulkley fluid using SPH method in Ansys-LS-DYNA. It'd be the best if I can input a loading curve of shear stress vs shear rate for the material model, or a combo of yield stress vs time and viscosity vs time. I was unable to find the exact material model compatible with SPH to use [I checked the material selector tool]. I was wondering if you can share some insights of alternative material models I can use? If fresh concrete specific models are unavailable, is there a generalized non-newtonian fluid model I can use? Am I able to customize a material model? Thank you!
My job doesn't run but gives this msg
Hi All,
I am reading up on the JH2 model for ceramics and trying to understand how the plastic strain increment is calculated. From literature, it says, "the plastic strain increment is the plastic strain during a cycle of integration". I'm assuming that's integrating the equivalent plastic strain rate, but then how does LS-DYNA compute the equivalent plastic strain rate using the JH2 model?
I found another resource says that for the JH2 model, the plastic strain incremement can also be computed via the current equivalent stress state and the radial return algorithm. If that's the case, where does the hardening modulus get derived from in the JH2 model, if at all?
Clarification is greatly appreciated.
PY
Hi all.
I also simulate rock drilling using SPH particles.
I use the increased density to speed up the solution to the problem. Increasing the density for SPH is not recommended, but I did such tests, I also do tests without increasing the density, they have not yet completed. But I have questions.
The task is similar to LSTC
https://www.lstc-cmmg.org/drilling
Only I use the rock and my feed and drilling speeds. I use an average speed of 25 m/s feed speed and 27 rad/s drilling speed. While solving the problem, I encountered several problems.
1. Particles scatter wildly. And when the particles fly apart, they pull the solid ring behind them and it is greatly distorted:
2.I reduced the density a little, the solution became better and I got good stress. I also replaced the EROSION contact with AUTOMATIC:
But the particles still fly away strongly and do not break off in large pieces. Why? how to deal with this? It happens like this: the drill pierces the particles, they begin to fly away more and more until the end of the calculation time.
I use concrete material JHC
