Dear All, A paper I found that may be of interest. This paper evaluates several concrete models using the high-fidelity physics-based code LS-DYNA with respect to their ability to simulate the response of high-strength concrete to a localized impact event. Each material model was subjected to a variety of quasi-static loading patterns at the single element level as well as projectile impact loading, and the results were compared against laboratory test data. Durant, B., Oesterie, M., and Magallanes, J., “Modeling Reinforced Concrete Protective Construction for Impact Scenarios”, International Explosives Safety Symposium and Exhibition (August, 2018), July, 2018. paper https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/intexpsafety/DurantPaper.pdf (usgovcloudapi.net) presentation https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/intexpsafety/Durant.pdf K&C Concrete Model, Release 4 The KCC-R4 material model was developed to extend the KCC-R3 model to more appropriately handle the quasi-brittle behaviors observed in high and ultra-high strength concretes. In the KCC-R4 formulation, a new additional internal damage variable λt is introduced for plastic deformation incurred under negative pressures (i.e., p<0). ). This is done to treat the quasi-brittle behaviors observed for concrete in a more appropriate way, in addition to providing a simple extension to incorporate anisotropy from the concrete’s cracking. The Release 4 version of the K&C concrete model is not yet implemented in LS-DYNA but can be utilized with a user-defined material model. Some of the improvements from the Release 3 version were discussed in the theoretical background section. Sincerely, James M. Kennedy KBS2 Inc. October 22, 2021 (two pdfs (Durant*) downloaded and put in jd's local ~/test/concrete folder 10/22/21) _____________________________________ *MAT_159 http://www.tfhrc.gov/safety/pubs/05063/index.htm http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/05062/ref.cfm *MAT_072R3 For better understanding of *mat_072r3, See these references ... - Malvar (1996), http://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete/concrete.CP27_WES96K.pdf. - 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://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete/mat_072r3.pdf. - "Recent Improvements to Release III of the K&C Concrete Model", Magallanes et al, http://www.dynalook.com/international-conf-2010/Simulation-1-4.pdf . - "K&C Concrete Material Model Release III—Automated Generation of Material Model Input, Malvar et al, 2000." (Contact Joe Magallanes at magallanes@kcse.com to request this one.) _______________________________________________________________ The following is from Jim Kennedy: would like to share some documentation for the concrete material models MAT_016, MAT_072, MAT_084, and MAT_096 I recently had gathered. This list is not all inclusive; just a list I had made. GENERAL Malvar, L.J., D. Simons, "Concrete Material Modeling in Explicit Computations," Workshop on Recent Advances in Computational Structural Dynamics and High Performance Computing, USAE Waterways Experiment Station, April 24-26, 1996. (http://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete/concrete.CP27_WES96K.pdf) A concrete impact analysis review paper I came across: Murthy, A.R.C., Palani, G.S., and Iyer, N.R., "Impact Analysis of Concrete Structural Components", Defense Science Journal, Vol. 60, No. 3, pp. 307-319, May, 2010. http://publications.drdo.gov.in/gsdl/collect/defences/index/assoc/HASH01a3/bafc6079.dir/doc.pdf MAT_016 I believe the following paper provides the basis for MAT_016 Pseudo_Tensor model: Burton, D.E., Lettis, L.A., Bryan, J.B., and Frary. N.R., "Physics and Numerics of the Tensor Code," Lawrence Livermore National Laboratory, Internal Document, UCID-19428, July ,1982. MAT_072 I believe the following paper provides the basis for MAT_072 Concrete_Damage model: Malvar, L.J., J.E. Crawford, J.W. Wesevich, and D. Simons, "A Plasticity Concrete Material Model for DYNA3D," International Journal of Impact Engineering, Volume 19, Numbers 9-10, pages 847-873, 1997. [From the mat_072 source code comments... "This material nodel is based on the work Malvar, Crawford and Wesevich. See Defense Nuclear Agency report DNA001-91-C-0059."] The following paper is a very recent update to MAT_072: 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://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete/mat_072r3.pdf or http://www.dynamore.de/download/af05/papers/H-I-49.pdf) You also might find the following paper of interest which uses both MAT_016 and MAT_072: Yonten, K., Manzari, M.T., Eskandarian, A., and Marzougui, D., "An Evaluation of Constitutive Models of Concrete in LS-DYNA Finite Element Code," 15th ASCE Engineering Mechanics Conference, New York, June, 2002. http://www.civil.columbia.edu/em2002/proceedings/papers/196.pdf I believe the reinforcement model for MAT_072 is the same as that for MAT_016 which is briefly described on page 20.72 of the LS-DYNA Version 970 User's Manual. MAT_084 I believe the following papers provide the basis for MAT_084 Winfrith_Concrete model. The last two are available in http://ftp.lstc.com/anonymous/outgoing/support/FAQ_kw/concrete (see Winfrith*.pdf) Ottosen, N.S., "A Failure Criterion for Concrete," Journal of the Engineering Mechanics Division, Volume. 103, Number 4, pages 527-535, July/August, 1977. Broadhouse, B.J., "DRASTIC - A Computer Code for Dynamic Anaylsis of Stress Transients in Reinforced Concrete," Safety and Engineering Science Division, United Kingdom Atomic Energy Authority, Winfrith, AEEW-R 2124, 1986. Broadhouse, B.J. and Neilson, A.J., "Modelling Reinforced Concrete Structures in DYNA3D," Safety and Engineering Science Division, United Kingdom Atomic Energy Authority, Winfrith, AEEW-M 2465, October, 1987. Paper presented at DYNA3D User Group Conference, London, September, 1987. Broadhouse, B.J., "The Winfrith Concrete Model in LS-DYNA3D," Safety Performance Department, Atomic Energy Authority Technology, Winfrith, SPD/D(95)363, February, 1995. A recent paper using the reinforced option: Algaard, W., Lyle, J. and Izatt, C., "Perforation of Composite Floors," 5th European LS-DYNA User's Conference, Birmingham, United Kingdom, May, 2005. http://www.dynalook.com/documents/5th_European_ls-dyna/Methods_Techniques_I/Algaard.pdf MAT_096 I believe the following paper provides the basis for MAT_096 Brittle-Damage model: Govindjee, S., Kay, G.J., and Simo, J.C., "Anisotropic Modelling and Numerical Simulation of Brittle Damage in Concrete," International Journal for Numerical Methods in Engineering, Volume 38, pages 3611-3633, 1995. Sincerely, James M. Kennedy KBS2 Inc. December 22, 2005