what's the difference between mat_15 (JC) and Mat_107(MJC) johnson cook model

[roc zhang]

Dear everyone,

      Could anyone explain or provide some original references about the differences between the JC model and modified JC model (assuming the Modified Johnson-Cook fracture criterion is used) There is also an option for the full coupling between ductile damage and the constitutive relation in the modified JC model, what's the differences between the coupling and uncoupling of damage model with the  constitutive relatio?

      Thanks a lot

Best Rregards

[James M. Kennedy]

Dear Zhang,

 

See if the following is of some interest:

 

Ballistic performance of vehicle armor layered metallic plates was investigated. The modified Johnson-Cook material model (*MAT_107) was used (data included) for all material parts. The simple Cockroft-Latham failure model was employed for failure. Element type and hourglass formulations were studied for their effect on results accuracy. A mesh sensitivity study was done for four different mesh sizes. The element size was changed through the thickness direction with residual velocity comparisons made:

 

Basaran, G., and Gurses, E., "Numerical Study of High Velocity Impact Response of Vehicle Armor Combination Using LS-DYNA", 11th European LS-DYNA Users Conference, Salzburg, Austria, May, 2017.

 

http://www.dynalook.com/11th-european-ls-dyna-conference/armor-penetration/numerical-study-of-the-high-velocity-impact-response-of-vehicle-armor-combination-using-ls-dyna

 

Andersen, K.H., and Hernandez, F.B., “Numerical Simulations of Docol 600 DL Steel Plates Subject to Blast Loading”, Master’s Thesis, Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway, June, 2013.

 

https://ntnuopen.ntnu.no/ntnu-xmlui/handle/11250/237305

 

Hallset, SW., and Haagenrud, J.S., “Combined Blast and Fragment Loading on Plates”, Master’s Thesis, Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway, June, 2011.

 

https://ntnuopen.ntnu.no/ntnu-xmlui/handle/11250/236902

 

Flores-Johnson, E.A., Saleh, M., and Edwards, L., “Ballistic Performance of a Multi-Layered Metallic Plates Impacted by a 7.62-mm APM2 Projectile”, International Journal of Impact Engineering, Vol. 38, Issue 12, pp1022-1032, December, 2011.

 

https://www.sciencedirect.com/science/article/abs/pii/S0734743X11001357

 

Jorgensen, K.C., and Swan, V., “Modeling of Armour-Piercing Projectile Perforation of Thick Aluminum Plates”, 13th International LS-DYNA Users Conference, Dearborn, Michigan, June, 2014.

 

https://www.dynalook.com/conferences/13th-international-ls-dyna-conference/simulation/modelling-of-armour-piercing-projectile-perforation-of-thick-aluminium-plates

 

Sincerely,

James M. Kennedy

KBS2 Inc.

January 10, 2022

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[James M. Kennedy]

Dear Zhang,

 

Some additional papers you might read.

 

There is some indication that the following presentation may have some mat_107 (mat_modified_johnson_cook) data for lead:

Borvik, T., Dey, S., and Clausen, A.H., "A Preliminary Study on the Perforation Resistance of High-Strength Steel Plates",8th International Conference on Mechanical and Physical Behavior of Materials under Dynamic Loading, Journal de Physique IV, Vol. 134, pp. 1053-1059, 2006.

http://jp4.journaldephysique.org/index.php?option=article&access=standard&Itemid=129&url=/articles/jp4/pdf/2006/03/jp4134161.pdf

Tore Borvik of Norwegian University of Science and Technology (NTNU) has used mat_107 (mat_modified_johnson_cook) data for lead.

Borvik, T., Dey, S., and Clausen, A.H., "Perforation Resistance of Five Different High-Strength Steel Plates Subjected to Small-Arms Projectiles", International Journal of Impact Engineering, Vol. 36, Issue 7, pp. 948-964, 2009.

http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V3K-4V4VY5D-3&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=1c06b0dddf985949211663bf5836f708

A coupled constitutive model of viscoplasticity and ductile damage for penetration and impact related problems has been formulated and implemented in the explicit finite element code LS-DYNA. This model (believed to be the basis for mat_107), which is based on the constitutive model and fracture strain model of Johnson and Cook, and on continuum damage mechanics as proposed by Lemaitre, includes linear thermoelasticity, the von Mises yield criterion, the associated flow rule, non-linear isotropic strain hardening, strain-rate hardening, temperature softening due to adiabatic heating, isotropic ductile damage and failure.

Borvik, T., Hopperstad, O.S., Berstad, T, and Langseth, M., "A Computational Model of Viscoplasticity and Ductile Damage for Impact and Penetration", European Journal of Mechanics -
A/Solids, Vol. 20, pp. 685-712, 2001.

http://cat.inist.fr/?aModele=afficheN&cpsidt=1119718
http://www.ingentaconnect.com/content/els/09977538/2001/00000020/00000005/art01157

Borvik, T, , Hopperstad, O.S., Berstad, T., and Langseth, M., "Perforation of 12 mm Thick Steel Plates by 20 mm Diameter Projectiles with Flat, Hemispherical and Conical Noses: Part II: Numerical Simulations", International Journal of Impact Engineering, Vol. 27, Issue 1, pp, 37-64, 2001.

http://cat.inist.fr/?aModele=afficheN&cpsidt=13485499

Borvik, T., Dey, S., and Clausen, A.H., "A Preliminary Study on the Perforation Resistance of High-Strength Steel Plates", 8th International Conference on Mechanical and Physical Behavior of Materials under Dynamic Loading, Journal de Physique IV, Vol. 134, pp. 1053-1059, 2006.

http://jp4.journaldephysique.org/index.php?option=article&access=standard&Itemid=129&url=/articles/jp4/pdf/2006/03/jp4134161.pdf

 

A note shared from Tore Borvik regarding their work:

Tore indicated to me that they had a lot of trouble (as did I) finding this type of data, because the bullet lead is not pure lead, it is antimony alloyed lead (which is much stronger), and it is very difficult to make material test coupons from these small parts. After some back and forth he came up with a set of material constants that may be used (see Tables 8-10 in separate email). Note that they are using the one parameter Cockcroft-Latham failure criterion instead of the 5 parameter JC failure criterion in these simulations. He stated that the CL model has shown to give similar results as the JC model in a number of impact simulations. He also states that it is possible to couple the CL criterion with JC hardening using material model 107 in LS-DYNA; it is also
possible to obtain the JC constants based on the CL criterion (with some calculations).

Dear everyone,

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