**Dr. Ricardo A.
Lebensohn**

**Scientist
4, Materials Science and Technology Division, Los Alamos National Laboratory**

__Contact__

** Address:** MST8, MS G755, Los
Alamos, NM, 87545, USA

** Phone
#:**
+1-505-665-3035

** Fax #:** +1-505-667-8021

*e-mail*** :** lebenso@lanl.gov

** Webpage: **http://public.lanl.gov/lebenso

*ResearcherID*** **(papers, citations, h-index):

__Education__

**1989:** *Licenciado** en Fisica*, Faculty of Science and
Engineering (FCEIA), Universidad Nacional de Rosario
(UNR), Argentina.

**1993:** PhD in Physics,
FCEIA, UNR, Rosario, Argentina.

__Awards__

**2011:** Defense Programs
Award of Excellence, National Nuclear Security Administration (NNSA), USA, as
part of the Process Engineering and Design for Improved Component Testing
(PREDICT) team, "in recognition of significant achievements in quality,
productivity, cost savings, safety, or creativity in support of NNSA's
programs".

**2010:** Humboldt
Research Award for Senior US Scientists, Humboldt Foundation, Germany,
"in recognition of a researcher's entire achievements to date to academics
whose fundamental discoveries, new theories, or insights have had a significant
impact on their own discipline".

**1997:** Fulbright
Scholarship. Department of Geology and Geophysics, University
of California, Berkeley, USA.

**Previous
Positions, Visiting Positions**

__Research Interests__

Mechanics of materials. Homogenization
and full-field solutions of mechanical properties of heterogeneous media.
Constitutive laws. Plastic
deformation, texture development and microstructure evolution of metals and
minerals.

__VPSC
(ViscoPlastic Self-Consistent) Code__

The code VPSC code
(developed and maintained by R.A. Lebensohn and C.N Tome) is a multipurpose polycrystal plasticity research code, based on the
knowledge of the mechanisms of slip and twinning that are active in single
crystals of arbitrary symmetry. VPSC can be used to predict the effective
stress-strain response, texture evolution, anisotropy, etc., and it is
presently used as a predictive tool for metallic and geological material
systems, for parameter identification, interpretation of experimental results
and multiscale calculations, in academic and
industrial applications, etc., by numerous research groups worldwide
(Presently, the VPSC code distribution list has more than 120 registered users
in Academia, National Laboratories and Industry).

Contact us, if you are interested in the
VPSC formulation and code ...

__Full-field
FFT-based Formulation__

This formulation (originally developed by P.
Suquet and coworkers as a fast algorithm to compute the linear and nonlinear
response of composites using as input a digital image of their microstructures)
has been adapted by us to treat 3-D polycrystals deforming by dislocation glide. The FFT-based
model provides an exact solution of the governing equations, has better
performance than a Finite Element calculation for the same purpose and
resolution, and can use voxelized microstructure data
as direct input.

Contact us, if you are interested in the
FFT-based formulation ...

__Most-cited
Articles__

1. R.A. Lebensohn and C.N. Tome: "A selfconsistent approach for the simulation of plastic
deformation and texture development of polycrystals:
application to Zirconium alloys". Acta Metallurgica et Materialia 41, pp 2611-2624 (1993). 578 citations. (PDF)

2. C.N. Tome, R.A. Lebensohn and U.F. Kocks: "A model for texture development dominated by
deformation twinning: application to Zirconium alloys". Acta Metallurgica et Materialia 39, pp 2667-2680
(1991). 161 citations. (PDF)

3. I.J. Beyerlein, R.A. Lebensohn and C.N. Tome:
Modeling of texture and microstructural evolution in the equal channel angular
process". Materials Science and Engineering A345,
pp.122-138 (2003). 98
citations. (PDF)

4. C.N. Tome, P.J.
Maudlin, R.A. Lebensohn and G.C. Kaschner:
"Mechanical response of zirconium. Part I: Derivation of a polycrystal constitutive law and finite element analysis".
Acta Materialia 49, pp 3085-3096 (2001). 96 citations. (PDF)

5. R.A Lebensohn and C. Tome: A
self-consistent visco-plastic model: calculation of
rolling textures of anisotropic materials". Material Science and
Engineering A 175, pp 71-82 (1994). 85 citations. (PDF)

6. R.A. Lebensohn: "N-site modelling of
a 3D viscoplastic polycrystal
using Fast Fourier Transform". Acta Materialia 49, pp 2723-2737 (2001).
77 citations. (PDF)

7. O. Castelnau, P. Duval, R.A. Lebensohn and
G. Canova: "Viscoplastic modelling of texture
development in polycrystalline ice with a self-consistent approach: comparison
with bound estimates". Journal of Geophysical Research B
101, pp 13851-13868 (1996). 71
citations. (PDF)

8. R.A. Lebensohn, Y. Liu and P. Ponte
Castaneda: "On the accuracy of the self-consistent approximation for polycrystals: comparison with full-field numerical
simulations". Acta Materialia 52, pp. 5347-5361 (2004).
52 citations. (PDF)

9. R.A. Lebensohn and G.R. Canova: A selfconsistent approach for modelling texture development
of two-phase polycrystals: application to Titanium
alloys". Acta Materialia 45, pp 3687-3694 (1997).
52 citations. (PDF)

10.
R.A. Lebensohn, C.N. Tome and P. Ponte Castaneda: "Self-consistent
modeling of the mechanical behavior of viscoplastic polycrystals incorporating intragranular
field fluctuations". Philosophical Magazine 87, pp.
4287-4322 (2007). 43
citations. (PDF)

11. C.N. Tome, R.A. Lebensohn and C.T Necker:
"Orientation correlations and anisotropy of recrystallized aluminium". Metallurgical and Materials Transactions
33A, pp 2635,2648 (2002). 37 citations. (PDF)

12. R.A. Lebensohn and C.N. Tome: "A
study of stress state associated with twinning nucleation and propagation in
anisotropic materials. Philosophical Magazine A 67, pp
187-206 (1993). 34 citations. (PDF)

13. R.A. Lebensohn R. Brenner, O. Castelnau
and A.D. Rollett: "Orientation image-based micromechanical modelling of subgrain texture evolution in polycrystalline copper".
Acta Materialia 56, pp. 3914-3926 (2008). 32 citations. (PDF)

14. O. Castelnau, H. Francillette, B. Bacroix and R.A.
Lebensohn: "Texture dependent plastic behavior of Zr-702 at large
strain". Journal of Nuclear Materials 297, pp 14-26
(2001). 31 citations. (PDF)

15.
R.A Lebensohn, H.-R. Wenk and C.N. Tome: "Modelling deformation and
recrystallization textures in calcite". Acta Materialia
46, pp 2683-2693 (1998). 31
citations. (PDF)

16.
R.A. Lebensohn, Y. Liu and P. Ponte Castaneda: "Macroscopic properties and
field fluctuations in model power-law polycrystals:
full-field solutions versus self-consistent estimates". Proceedings of the
Royal Society of London A 460, pp. 1381-1405 (2004). 28 citations. (PDF)

17. D. Hughes, R.A. Lebensohn, H.-R. Wenk and
A. Kumar: "Stacking fault energy and microstructure effect on torsion
texture evolution". Proceedings of the Royal Society of London A 456, pp 921-954 (2000). 28 citations. (PDF)

18. B. Plunkett, R.
A. Lebensohn, O. Cazacu and F. Barlat: "Evolving
yield function of hexagonal materials taking into account texture development
and anisotropic hardening". Acta Materialia 54, pp. 4159-4169 (2006).
27 citations. (PDF)

19. T. Takeshita, H.-R. Wenk and R. Lebensohn: "Development of
preferred orientation and microstructure in sheared quartzite: comparison of
natural data and simulated results". Tectonophysics 312, pp. 133-155 (1999). 27 citations*.*
(PDF)

20. H.-R. Wenk, J.R. Baumgardner,
R.A. Lebensohn and C.N. Tome: "A convection model to explain anisotropy of
the inner core". Journal of Geophysical Research B 105,
pp 5663-5673 (2000). 26
citations. (PDF)

21. R.A. Lebensohn, P.A. Turner, J.W. Signorelli,
G.R. Canova and C.N. Tome: "Calculation of intergranular
stresses based on a large strain viscoplastic selfconsistent polycyrstal
model". Modelling and Simulation in Materials Science
and Engineering 6, pp 447-465 (1998). 26 citations. (PDF)

22. O. Castelnau, G.R. Canova, R.A. Lebensohn
and P. Duval: "Modelling viscoplastic behavior
of anisotropic polycrystalline ice with a selfconsistent
approach". Acta Materialia 45, pp 4828-4834 (1997). 25 citations. (PDF)

23. R.
Lebensohn, H. Uhlenhut, C. Hartig
and H. Mecking: "Mechanical behavior gamma-TiAl-based polysinthetically
twinned crystals: micromechanical modelling and experimental validation". Acta Materialia 46, pp. 4701-4709 (1998). 25 citations. (PDF)

__Recent
Articles (2009-2012)__

70.
J.P. Escobedo, E.K. Cerreta, C.P. Trujillo, D.T. Martinez, R.A. Lebensohn, V.A.
Webster and G.T. Gray III: "Influence of texture and test velocity on the
dynamic, high strain, tensile behavior of zirconium". Acta Materialia,
60, pp. 4379-4392 (2012). (PDF)

69.
R.A. Lebensohn, M.I. Idiart, P.
Ponte Castaneda: "Modeling microstructural effects in dilatational
plasticity of polycrystalline materials". Procedia IUTAM 3, pp. 314-330
(2012). (PDF)

68.
R.A. Lebensohn, R.A. Holt, J.A. Caro, A. Alankar and C.N. Tome: "Improved
constitutive description of single crystal viscoplastic
deformation by dislocation climb". Comptes Rendus Mecanique
340, pp. 289-295 (2012). (PDF)

67.
A.K. Kanjarla, R.A. Lebensohn, L. Balogh and C.N. Tome: "Study of internal
lattice strain distribution in stainless steel using a full-field elasto-viscoplastic formulation based on fast Fourier
transforms". Acta Materialia 60, pp. 3094-3106 (2012).
(PDF)

66.
R.A Lebensohn, A.K. Kanjarla and P. Eisenlohr:
"An elasto-viscoplastic formulation based on
fast Fourier transforms for the prediction of micromechanical fields in
polycrystalline materials". International Journal of
Plasticity 32-33, pp. 59-69 (2012). (PDF)

65.
G. Lefebvre, C.W. Sinclair, R.A. Lebensohn and J.D. Mithieux:
"Accounting for local interactions in the prediction of roping of ferritic stainless steel sheets". Modelling
and Simulation in Materials Science and Engineering 20, 024008 (16pp) (2012).
(PDF)

64.
M. Knezevic, L. Capolungo, C.N. Tome, R.A. Lebensohn, D.J. Alexander and B.
Mihaila, R.J. McCabe: "Anisotropic stress-strain response and
microstructure evolution of textured alpha-uranium". Acta Materialia
60, pp. 702-715 (2012). (PDF)

63.
J. Segurado, R.A. Lebensohn, J. LLorca and C.N. Tome:
"Multiscale modeling of plasticity based on
embedding the viscoplastic self-consistent
formulation in implicit finite elements". International
Journal of Plasticity 28, pp. 124-140 (2012). (PDF)

62.
R. Deguen, P. Cardin, S. Merkel and R.A. Lebensohn:
"Texturing in the Earth's inner core due to preferential growth in its
equatorial belt". Physics of the Earth and Planetary
Interiors 188, pp. 173-184 (2011). (PDF)

61.
M. Friak, T. Hickel, B.
Grabowski, L. Lymperakis, A. Udyansky,
A. Dick, D. Ma, F. Roters, L.-F. Zhu, A. Schlieter,
U. Kuhn, Z. Ebrahimi, R.A. Lebensohn, D. Holec, J. Eckert, H. Emmerich, D.
Raabe and J. Neugebauer:
"Methodological challenges in combining quantum-mechanical and continuum
approaches for materials science applications". European
Physical Journal Plus 126, pp. 101-123 (2011). (PDF)

60.
J.P. Escobedo, E.K. Cerreta, D. Dennis-Koller, B.M. Patterson, C. Bronkhorst,
B. Hansen, D. Tonks and R.A. Lebensohn: "Effects of grain size and
boundary structure on the dynamic tensile response of copper". Journal of Applied Physics 110, 033513 (2011). (PDF)

59.
R.A. Lebensohn, M.I. Idiart, P. Ponte Castaneda and
P.G. Vincent: "Dilatational viscoplasticity of
polycrystalline solids with intergranular
cavities". Philosophical Magazine 91, pp. 3038-3067
(2011). (PDF)

58.
M. Montagnat, J. Blackford, S. Piazolo,
L. Arnaud and R.A. Lebensohn: "Measurement and full-field prediction of
deformation heterogeneities in ice". Earth and Planetary
Science Letters 305, pp. 153-160 (2011). (PDF)

57.
S.B. Lee, R.A. Lebensohn and A.D. Rollett: "Modeling the viscoplastic micromechanical response of two-phase
materials using fast Fourier transforms". International
Journal of Plasticity 27, pp. 707-727 (2011). (PDF)

56.
R.A. Lebensohn, A.D. Rollett and P. Suquet: "Fast Fourier Transform-based
modelling for the determination of micromechanical fields in polycrystals". Journal of the
Minerals, Metals and Materials Society (JOM) 63, pp. 13-18 (2011). (PDF)

55.
A. Griera, P. Bons, M.W. Jessell, R.A. Lebensohn, L. Evans and E. Gomez-Rivas:
"Strain localization and porphyroclast
rotation". Geology 39, pp. 275-278 (2011). (PDF)

54.
B. Liu, D. Raabe, F. Roters, P. Eisenlohr and R.A.
Lebensohn: "Comparison of Finite Element and fast Fourier full-field
crystal plasticity solvers for texture prediction". Modelling
and Simulation in Materials Science and Engineering 18, 085005 (21pp) (2010).
(PDF)

53.
O. Castelnau, P. Cordier, R.A. Lebensohn, S. Merkel
and P. Raterron: "Microstructures and rheology
of the Earth upper mantle inferred from a multiscale
approach". Comptes Rendus Physique 11, pp. 304-315 (2010).
(PDF)

52.
A.D. Rollett, R.A. Lebensohn, M. Groeber, Y. Choi, J. Li and G.S. Rohrer:
"Stress hot spots in viscoplastic deformation of
polycrystals". Modelling and
Simulation in Materials Science and Engineering 18, 074005 (16pp) (2010).
(PDF)

51.
M.E Nixon, R.A. Lebensohn, O. Cazacu and C. Liu:
"Experimental and finite-element analysis of the anisotropic response of
high-purity alpha-titanium in bending". Acta Materialia
58, pp. 5759-5767 (2010). (PDF)

50.
M.E Nixon, O. Cazacu and R.A. Lebensohn:
"Anisotropic response of high-purity alpha-titanium. Experimental
characterization and constitutive modelling". International
Journal of Plasticity 26, pp. 516-532 (2010). (PDF)

49. R.A. Lebensohn,
C.S. Hartley, C.N. Tome and O. Castelnau: "Modelling the mechanical response of polycrystals deforming by climb and glide". Philosophical Magazine 90, pp. 567-583 (2010). (PDF)

48.
A. Prakash and R.A. Lebensohn: "Simulation of micromechanical behavior of polycrystals: finite elements vs. fast Fourier
transforms". Modelling and Simulation in Materials
Science and Engineering 17, 064010 (16pp) (2009). (PDF)

47. R. Brenner, R.A. Lebensohn and O.
Castelnau: "Elastic anisotropy and yield surface estimates of polycrystals". International Journal
of Solids and Structures 46, pp. 3018-3026 (2009). (PDF)

46. R.A. Lebensohn,
M. Montagnat, P. Mansuy, P.
Duval, J. Meysonnier and A. Philip: "Modeling viscoplastic behavior and heterogenous
intracrystalline deformation of columnar ice polycrystals". Acta Materialia, 57, pp. 1405-1415 (2009). (PDF)

**Articles in Peer-Reviewed International Journals (full
list, 70)**

**Articles in Proceedings of International Conferences
(44)**

__News:__

*Two
papers in the current TOP25 hottest articles list of International Journal of
Plasticity*

__Ricardo Lebensohn receives Humboldt
Research Award__

__Ricardo
Lebensohn joins to the Editorial Board of International Journal of Plasticity__

*Lebensohn,
Tome & Ponte Castaneda 2007 paper in most cited list of Philosophical
Magazine*

__New Book Chapter:__** **

R.A. Lebensohn, P.
Ponte Castaneda, R. Brenner and O. Castelnau: "Full-field vs.
homogenization methods to predict microstructure-property relationships of
polycrystalline materials". Chapter 11 of Computational
Methods for Microstructure-Property Relationships. S Ghosh and D. Dimiduk (Eds.), Springer, pp. 393-441 (2011).

__Recent and Upcoming
Invited Lectures: __

"Different strategies
to model microstructural effects on the dilatational plastic behavior of porous
polycrystalline materials". Keynote Lecture. Symposium on
Homogenization Strategies for Multiphase Materials, European Solid Mechanics
Conference, Graz, Austria, July 2012.

"Multiscale computational homogenization of porous
polycrystalline materials". Invited Lecture.
EUROMECH Colloquium on Multi-scale Computational Homogenization of
Heterogeneous Structures and Materials, Marne-la-Vallee,
France, March 2012.

"Micromechanical modelling of polycrystals using Fast Fourier Transforms".
PRISM Seminar. Center for Prediction of Reliability,
Integrity and Survivability of Microsystems (PRISM), Purdue University, West
Lafayette, IN, USA, January 2012.

"FFT-based
methods: towards direct input and validation of micromechanical models using
3-D microstructural data". Invited
Lecture. Workshop on high-energy x-ray diffraction experiments and
detailed computational analyses for understanding multiscale
phenomena in crystalline materials, Advance Photon Source (APS), Chicago, IL,
USA, October 2011.

"Modeling ductile
damage of polycrystalline materials".
Keynote Lecture. IUTAM Symposium on Linking Scales in Computations: from
Microstructure to Macro-scale Properties, Pensacola, FL, USA, May 2011.

"Micromechanics of
polycrystals: full-field computations and
second-order homogenization approaches". GALCIT
Colloquium. Graduate Aerospace Laboratories California Institute of
Technology (GALCIT), Caltech, Pasadena, CA, USA, October 8, 2010.

"Crystal Plasticity Fast Fourier Transform-based formulation: theory and applications". F2M Seminar, Federation Francilienne de Mecanique (F2M), Paris, France, May 6, 2010.

"Modeling
LPO evolution using crystal plasticity at conditions relevant to the Earth's
interior: exploring the role of dislocation climb". Invited Talk, 2010
Gordon Research Conference on Rock Deformation, Tilton School, NH, USA, August 8-13, 2010.

__Recent____ and Upcoming Summer Schools:__

Ecole Thematique "Changement d'Echelles en Mecanique de Materiaux".
Briancon (France), August
22-September 3, 2010.

__Recent and Upcoming
Symposia:__

"Computational
homogenization of single and multi-phase polycrystalline aggregates",
organized by L. Delannay (UC Louvain, Belgium), J. Segurado (UP Madrid, Spain)
and R.A. Lebensohn (Los Alamos, USA), within the context of IV
European Congress on Computational Mechanics (ECCM IV).

__Recent Projects:__

ExMatEx:
Exascale Co-Design Center for Materials in Extreme
Environments

__Last
update__: August 20, 2012 - Disclaimers/Policy