Faculty - Bobaru

Florin Bobaru, Professor


Florin Bobaru

Florin Bobaru
Professor

Mechanical & Materials Engineering
University of Nebraska–Lincoln
W307 Nebraska Hall
Lincoln, Nebraska 68588-0526
Office: 402-472-8348

Education

  • Ph.D., Theoretical and Applied Mechanics, Cornell University, Ithaca, NY, 2001
  • M.S., Mathematics and Mechanics of Solids, University of Bucharest, Romania, 1997
  • B.S., Mathematics and Mechanics, University of Bucharest, Romania, 1995

Research Assistantships Available and New Papers

  • Graduate Research Assistanships avaiable NOW for candidates pursuing a Ph.D. degree. Strong computational modeling and mechanics/thermal background required. Contact me directly at fbobaru2.at.unl.edu
  • Check out our new paper on peridynamic modeling of corrosion damage in Journal of the Mechanics and Physics of Solids (JMPS): http://dx.doi.org/10.1016/j.jmps.2015.02.015

Areas of Research and Professional Interests

  • Damage and fracture with peridynamics
  • Modeling of corrosion damage and stress corrosion cracking
  • Failure in heterogeneous materials (fiber-reinforced composites, polycrystalline ceramics, etc.)
  • Dynamics of Granular Materials
  • Optimization of material composition and optimal shape design

About Florin Bobaru

Have you ever wondered why does glass break in such complex patterns, fragments and chips? Our research group proposes computational models that answer such questions and explain the behavior observed experimentally in some of the most challenging problems that have puzzled researchers for decades. We apply our models to a variety of fields, from heat and mass diffusion to dynamic fracture and fragmentation. Recent focus is on: peridynamics for fracture and impact in glass, polycrystalline ceramics, and fiber-reinforced composites, modeling of corrosion damage and Stress Corrosion Cracking, dynamics of granular materials and their interaction with vibrating structures, multidisciplinary optimization, inverse problems, and multiscale and multiphysics methods.

Damage and fracture with peridynamics
The peridynamic formulation is a novel reformulation of the classical continuum mechanics theory which allows one to model material failure and damage in a natural way. In peridynamics, cracks are part of the solution, not part of the problem. We have used such models to explain the role Van der Waals forces play in the deformation and damage behavior of nanofiber networks, to explain the growth of cracks and fragmentation evolution in glass plates, to model trans- and intergranular fracture in polycrystalline ceramics, to discover strain-rate effects in the failure of fiber-reinforced composites, and to simulate the growth of subsurface damage in corrosion. This research is being funded by AFOSR through a MURI project, by ONR, by NAVAIR, by ARO and ARL. Recent past funding includes grants from Boeing Co, Sandia National Laboratories, Callahan Innovation (New Zealand), NASA.

Dynamics of Granular Materials interacting with vibrating plates
Granular materials are one of the most puzzling material systems. Their dynamic behavior is, to a large extent, still unknown. The models we proposed, simulate the dynamic interaction between a layer of granular material and an elastic vibrating plate to provide us with a deeper understanding of the fascinating dynamic behavior of granular materials

Optimization of material composition
Can one find the "best" composition of a multi-component material (such as a composite or a functionally graded material - FGM) to increaase its strength or stiffness, or reduce its mass? Our results on optimal material design of FGMs show that new possible architectures when trying to minimize the chance of failure due to thermal and mechanical stresses.

Optimal shape design
What is the best shape of a cooling thermal fin? Our novel algorithms compute optimal shape of systems when there are large shape changes between the initial guess and the final optimal design. Our meshfree approach leads to interesting solutions that mimic naturally occurring systems like the plates on the back of a stegosaurus dinosaur, or the extended surfaces on the inner side of the intestine (intestinal villi).

Experience

Employee History:
  • University of Nebraska–Lincoln, Professor, Mechanical & Materials Engineering, 2013 – present
  • Visiting Associate Professor, Mechanical and Civil Engineering, California Institute of Technology, Pasadena, California, USA, April-August 2011
  • Visiting Scholar, Multiscale Dynamic Material Modeling Department, Sandia National Laboratories, Albuquerque, New Mexico, USA, January-March 2009
  • Visiting Scholar, Fracture Group, Cavendish Lab, University of Cambridge, Cambridge, U.K., September-December 2008
  • University of Nebraska–Lincoln, Associate Professor, Department of Engineering Mechanics, 2007 – 2013
  • University of Nebraska–Lincoln, Assistant Professor, Department of Engineering Mechanics, 2001 – 2007
  • Sandia National Laboratories, Computer Science Research Institute, Albuquerque, NM. Summer Research Fellow. 2002 – 2004, 2005
  • Cornell University, Ithaca, NY. Graduate Teaching and Research Assistant. 1996-2000

Funding

  • AFOSR MURI center for center for material failure prediction through peridynamics (2014-2019)
  • ONR (2015-2018)
  • NAVAIR (2014-2015)
  • ARO/ARL (2010-2016)
  • Boeing Co.
  • NASA

Selected Publications

h-index = 17, i10-index=22, over 900 citations (Google Scholar, March 2015)


  • Z. Chen, F. Bobaru, "Peridynamics modeling of pitting corrosion damage", Journal of the Mechanics and Physics of Solids (2015), http://dx.doi.org/10.1016/j.jmps.2015.02.015.
  • W. Hu, Y. Wang, J. Yu, C.F. Yen, F. Bobaru, “Impact damage on a thin glass with a thin polycarbonate backing”, International Journal of Impact Engineering, 62: 152- 165 (2013).
  • F. Bobaru, YD. Ha, and W. Hu, “Damage progression from impact in layered glass modeled with peridynamics”, Open Engineering, 2(4): 551-561 (2012).
  • F. Bobaru and W. Hu, “The meaning, selection, and use of the Peridynamic horizon and its relation to crack branching in brittle materials” International Journal of Fracture, 176: 215–222 (2012).
  • W. Hu, YD. Ha, F. Bobaru, and S.A. Silling, “The formulation and computation of the nonlocal J-integral in bond-based Peridynamics”, International Journal of Fracture, 176: 195–206 (2012).
  • W. Hu, YD. Ha, and F. Bobaru, “Peridynamic model for dynamic fracture in unidirectional fiber-reinforced composites”, Computer Methods in Applied Mechanics and Engineering, 217–220: 247–261 (2012).
  • F. Bobaru and M. Duangpanya, “A Peridynamic Formulation for Transient Heat Conduction in Bodies with Evolving Discontinuities”, Journal of Computational Physics, 231(7): 2764-2785 (2012).
  • YD. Ha and F. Bobaru, “Characteristics of dynamic brittle fracture captured with peridynamics”,Engineering Fracture Mechanics, 78: 1156–1168 (2011). doi:10.1016/j.engfracmech.2010.11.020.
  • F. Bobaru and YD. Ha, “Adaptive refinement and multiscale modeling in 2D Peridynamics”,International Journal for Multiscale Computational Engineering, 9(6): 635-659 (2011).
  • F. Bobaru, “Peridynamics and Multiscale Modeling” Editorial in Special Issue on “Advances in Peridynamics”, International Journal for Multiscale Computational Engineering, 9(6): vii-ix (2011).
  • W. Hu, YD. Ha, and F. Bobaru. “Modeling Dynamic Fracture and Damage in Fiber-Reinforced Composites with Peridynamics”, International Journal for Multiscale Computational Engineering,9(6): 707–726 (2011).
  • A.L. Collins, J.W. Addiss, S.M. Walley, K. Promratana, F. Bobaru, W.G. Proud, D.M. Williamson, “The effect of rod nose shape on the internal flow fields during the ballistic penetration of sand”,International Journal of Impact Engineering, 38(12): 951-963 (2011).
  • F. Bobaru and M. Duangpanya, “The peridynamic formulation for transient heat conduction,”International Journal of Heat and Mass Transfer, 53(19-20): 4047-4059 (2010).
  • YD. Ha and F. Bobaru, “Studies of dynamic crack propagation and crack branching with peridynamics,” International Journal of Fracture, 162(1-2): 229-244 (2010).
  • S. A. Silling, O. Weckner, E. Askari, and F. Bobaru, “Crack nucleation in a peridynamic solid,”International Journal of Fracture, 162(1-2): 219-227 (2010).
  • F. Bobaru, M. Yang, L.F. Alves, S.A. Silling, E. Askari, and J. Xu, “Convergence, adaptive refinement, and scaling in 1D peridynamics”, International Journal for Numerical Methods in Engineering, 77: 852-877 (2009).
  • Principal Guest Editor: Florin Bobaru, J.S. Chen, Joseph A. Turner, "Advances in the Dynamics of Granular Materials", Mechanics of Materials, 41(6): 635-636, June 2009.