MAT72REL3

Kağan GENÇ

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Feb 25, 2021, 4:52:15 PM2/25/21

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Hello dear group members,

I try to create a model including the concrete model namely MAT72REL3. Due to the lack of experimental data for material inputs, I do not have any EOS-8 paramenters for 50 MPa concrete. As I have read from an article, these data can be automatically generated with a single parameter(fc). When I put this data to the material's input, the EOS parameters were not generated and I got the error about the absence of EOS. Is there anyone who knows how those EOS parameters for the concrete model can be automatically generated?

Also, I have seen an article several times namely "K&C Concrete Material Model Release III—Automated Generation of Material Model Input" which was referenced many times. However, I could not find the pdf of it. If anyone has, I would be thankful to be sent.

Respectfully,

Oguz Kagan Genc

James M. Kennedy

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Feb 25, 2021, 6:33:08 PM2/25/21

to Kağan GENÇ, LS-DYNA2

Dear Kagan,

A note I have shared previously that may be of some help when using simplified

concrete modeling input and how the concrete parameter data can be modified

once an initial run has been made. I hope that most of this information is still

reasonably accurate.

-----------------------------------------------

Added noted describing simplified input –

Initially all you need to do is provide 3 input data with 3 cards and then run

the program. From the output files (messag and/or d3hsp), you will find data

generated with all the input data you need. You can then put all this new data

with EOS8 back in your input file and rerun it.

The initial input data are as follow: -45.6 for concrete compressive strength,

145 for changing the stress unit from psi-MPa and 0.003972 for converting

inches to millimeter. In the first run the rest of the cards are left blank.

A reworded note saying the same thing as previous paragraphs.

Note that these a0f and a1f defaults will be overridden by non zero entries on

Card 3. If plastic strain or damage scaling is desired, Cards 5 through 8 and b1

should be specified in the input. When a0 is input as a negative quantity, the

equation-of-state can be given as 0 and a trilinear EOS Type 8 model will be

automatically generated from the unconfined compressive strength and Poisson's

ratio. The EOS 8 model is a simple pressure versus volumetric strain model with

no internal energy terms, and should give reasonable results for pressures up to

5kbar (approximately 75,000 psi).

An example of “Simple Input for Concrete” is given in the LS-DYNA

User’s Manual under *MAT_CONCRETE_DAMAGE_REL3 keyword:

http://ftp.lstc.com/anonymous/outgoing/jday/manuals/DRAFT_Vol_II.pdf

-----------------------------------------------

"LS-DYNA Keyword User's Manual - Volume II: Material Models", LS-DYNA

Dev/Revision 13521, Livermore Software Technology Corporation, Livermore,

California, February, 2021.

http://ftp.lstc.com/anonymous/outgoing/jday/manuals/DRAFT_Vol_II.pdf

If you use the *MAT_072R3 auto-generation feature, it will generate the EOS.

Seven card images are required to define the complete set of model parameters for the

K&C Concrete Model. An Equation-of-State is also required for the pressure-volume

strain response. Brief descriptions of all the input parameters are provided below,

however it is expected that this model will be used primarily with the option to

automatically generate the model parameters based on the unconfined compression

strength of the concrete. These generated material parameters, along with the

generated parameters for *EOS_TABULATED_COMPACTION, are written to the

d3hsp file.

-----------------------------------------------

*MAT_016

Note that these a0f and a1f defaults will be overridden by non zero entries on Card 3. If plastic strain or damage scaling is desired, Cards 5 through 8 and b1 should be specified in the input. When a0 is input as a negative quantity, the equation-of-state can be given as 0 and a trilinear EOS Type 8 model will be automatically generated from the unconfined compressive strength and Poisson's ratio. The EOS 8 model is a simple pressure versus volumetric strain model with no internal energy terms, and should give reasonable results for pressures up to 5kbar (approximately 75,000 psi).

-----------------------------------------------

This information was not available during a period (at least not from these two formal

releases - LS-DYNA V971 R5.1 (R5.64536) and LS-DYNA V971 R5.1.1 (R5.65550).

I did some testing, and the last release I was able to get that information echoed out to

the 'messag' file was LS-DYNA V971 R5.0 (R5.59419). It appears that it was added

back in the 'messag' file sometime earlier this year. If you using older executables which

do not have the "Generated Input" placed in your 'messag' file (an example given here):

$--------------------------- MATERIAL CARDS ------------------------------------

$ LS-DYNA Keyword Generated Input for Release III

$ [Default values = K&C generic f'c=6580 psi concrete]

*MAT_Concrete_Damage_Rel3

$ MATID RO PR

72 2.500E-03 2.000E-01

$ ft A0 A1 A2 B1 OMEGA A1F

3.218E+00 1.035E+01 4.463E-01 2.309E-03 1.600E+00 5.000E-01 4.417E-01

$ sLambda NOUT EDROP RSIZE UCF LCRate LocWidth NPTS

1.000E+02 2.000E+00 1.000E+00 3.940E-02 1.450E+02 0.000E+00 2.538E+01 1.300E+01

$ Lambda01 Lambda02 Lambda03 Lambda04 Lambda05 Lambda06 Lambda07 Lambda08

0.000E+00 8.000E-06 2.400E-05 4.000E-05 5.600E-05 7.200E-05 8.800E-05 3.200E-04

$ Lambda09 Lambda10 Lambda11 Lambda12 Lambda13 B3 A0Y A1Y

5.200E-04 5.700E-04 1.000E+00 1.000E+01 1.000E+10 1.150E+00 7.812E+00 6.250E-01

$ Eta01 Eta02 Eta03 Eta04 Eta05 Eta06 Eta07 Eta08

0.000E+00 8.500E-01 9.700E-01 9.900E-01 1.000E+00 9.900E-01 9.700E-01 5.000E-01

$ Eta09 Eta10 Eta11 Eta012 Eta13 B2 A2F A2Y

1.000E-01 0.000E+00 0.000E+00 0.000E+00 0.000E+00 1.350E+00 3.380E-03 7.357E-03

$--------------------------- EOS-8 CARDS -------------------------------------

$ Generated EOS 8 (Tabulated Compaction)

*EOS_Tabulated_Compaction

$ EOSID Gamma E0 Vol0

72 0.000E+00 0.000E+00 1.000E+00

$ VolStrain01 VolStrain02 VolStrain03 VolStrain04 VolStrain05

0.00000000E+00 -1.50000000E-03 -4.30000000E-03 -1.01000000E-02 -3.05000000E-02

$ VolStrain06 VolStrain07 VolStrain08 VolStrain09 VolStrain10

-5.13000000E-02 -7.26000000E-02 -9.43000000E-02 -1.74000000E-01 -2.08000000E-01

$ Pressure01 Pressure02 Pressure03 Pressure04 Pressure05

0.00000000E+00 2.33369250E+01 5.08744965E+01 8.16792375E+01 1.55190551E+02

$ Pressure06 Pressure07 Pressure08 Pressure09 Pressure10

2.34069358E+02 3.32084443E+02 5.08044857E+02 2.96612317E+03 4.53669822E+03

$ Multipliers of Gamma*E

.000000000E+00 .000000000E+00 .000000000E+00

$ BulkUnld01 BulkUnld02 BulkUnld03 BulkUnld04 BulkUnld05

1.55579500E+04 1.55579500E+04 1.57757613E+04 1.65692168E+04 1.97119227E+04

$ BulkUnld06 BulkUnld07 BulkUnld08 BulkUnld09 BulkUnld10

2.28701865E+04 2.60128924E+04 2.83932588E+04 6.38809427E+04 7.77897500E+04

$-------------------------------------------------------------------------------

You can simply create it with a little effort by taking the information provided in the

'd3hsp' file (example given here - you simply have to do a little typing):

$-------------------------------------------------------------------------------

principal material properties:

vnu .............................. = 2.000E-01

unconfined compressive strength .. = 3.500E+01

unit conversion factor for f'c ... = 1.450E+02

tensile cutoff (max. prin. stress) = 3.218E+00

maximum failure surface a0 ....... = 1.035E+01

maximum failure surface a1 ....... = 4.463E-01

maximum failure surface a2 ....... = 2.309E-03

yield failure surface a0y ........ = 7.812E+00

yield failure surface a1y ........ = 6.250E-01

yield failure surface a2y ........ = 7.357E-03

damage scaling factor b1.......... = 1.600E+00

damage scaling factor b2.......... = 1.350E+00

damage scaling factor b3.......... = 1.150E+00

load curve for strain-rate scaling = 0

tensile strength (max ppal stress) = 3.218E+00

amount of partial associativity w = 5.000E-01

residual failure surface a0f ..... = 0.000E+00

residual failure surface a1f ..... = 4.417E-01

residual failure surface a2f ..... = 3.380E-03

Damage Function Lambda_i ......... = 0.000E+00 8.000E-06 2.400E-05 4.000E-05 5.600E-05 7.200E-05 8.800E-05

.................................. = 3.200E-04 5.200E-04 5.700E-04 1.000E+00 1.000E+01 1.000E+10

Scale Factor Eta_i ..... ......... = 0.000E+00 8.500E-01 9.700E-01 9.900E-01 1.000E+00 9.900E-01 9.700E-01

.................................. = 5.000E-01 1.000E-01 0.000E+00 0.000E+00 0.000E+00 0.000E+00

other properties:

% of lambda stretching ........... = 1.000E+02

epx1 output selector ............. = 2.000E+00

edrop ............................ = 1.000E+00

length unit conversion factor .... = 3.940E-02

ucf............................... = 1.450E+02

localization width (3 max aggr size) 2.538E+01

volumetric strain ................ = 0.0000E+00 -0.1500E-02 -0.4300E-02 -0.1010E-01 -0.3050E-01

volumetric strain ................ = -0.5130E-01 -0.7260E-01 -0.9430E-01 -0.1740E+00 -0.2080E+00

pressure with e=0 ................ = 0.0000E+00 0.2334E+02 0.5087E+02 0.8168E+02 0.1552E+03

pressure with e=0 ................ = 0.2341E+03 0.3321E+03 0.5080E+03 0.2966E+04 0.4537E+04

multiplier of gamma*e ............ = 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00 0.0000E+00

unloading bulk modulus ........... = 0.1556E+05 0.1556E+05 0.1578E+05 0.1657E+05 0.1971E+05

unloading bulk modulus ........... = 0.2287E+05 0.2601E+05 0.2839E+05 0.6388E+05 0.7779E+05

gamma ............................ = 0.00000E+00

e0 ............................... = 0.00000E+00

$-------------------------------------------------------------------------------

Some references offered by Len Schwer:

------------------------------------------------

I would suggest that you consider using one of the simple input concrete models,

MAT016, MAT073R3, MAT085, or MAT159 to model the rock material, and see

if you can replicate this situation you found using your user-defined material model.

Perhaps the following three papers may be of some help:

Schwer, L.E., and Malvar, L.J., "Simplified Concrete Modeling with *MAT_

CONCRETE_DAMAGE_REL3", 4th German LS-DYNA Forum, Bamberg ,

Germany , October, 2005.

http://www.dynamore.de/en/downloads/papers/05-forum/papers-depr/simplified-concrete-modeling-with-mat-concret/

Schwer, L.E., and Malvar, L.J., "Simplified Concrete Modeling with *MAT_

CONCRETE_DAMAGE_REL3", JRI LS-DYNA User Week, Nagoya , Japan ,
November, 2005.

http://www.geomaterialmodeling.com/pdf/186concrete.pdf
http://www.geomaterialmodeling.com/pdf/88briefly.pdf

Schwer, L.E., "Simple Input Concrete Constitutive Models: An Illustration
of Brick Walls & Concrete Cylinder Perforation", 10th International LS-DYNA
User's Conference, Dearborn , Michigan , June, 2008.

http://www.dynalook.com/international-conf-2008/PenetrationBlast-4.pdf

------------------------------------------------

Additional, but limited distribution reference materials, e.g. Crawford and Malvar

[1997], Malvar, et al. [2000], Crawford and Malvar [2006], may be obtained by

contacting Karagozian & Case.

Malvar, L.J., Crawford, J.E., and Morrill, K.B., "K&C Concrete Material Model

Release III-Automated Generation of Material Model Input", TR-99-24-B1,

Karagozian and Case Structural Engineers, Burbank, California, August, 2000

(Limited Distribution).

------------------------------------------------

Sincerely,

James M. Kennedy

KBS2 Inc.

February 25, 2021

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James M. Kennedy

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Feb 25, 2021, 6:35:53 PM2/25/21

to Kağan GENÇ, LS-DYNA2

This information was not available during a period (at least not from these two formal