Awards & Honors:
My research focuses on the development and application of theoretical, computational and experimental techniques to characterize the response of materials and structures to mechanical, thermal, and environmental loads. I am particularly interested in characterizing the mechanics of fatigue and fracture. My multidisciplinary research, which has been funded by the National Science Foundation, the National Institutes of Health, the Office of Naval Research, the United States Air Force, NASA and the Ohio and Minnesota Departments of Transportation has been applied to problems arising in civil engineering, mechanical and aerospace engineering, materials science, electromechanical systems, biological tissues and prosthetic design. I have published over ninety papers in the top refereed journals, including Science and Nature, and several of my research projects have been featured in the popular press, including the New York Times Science Times, American Scientist, Science News, Business Week, Financial Times, Geo, Pour La Science and Industry Week. My current research involves the design and testing of a new earthquake energy dissipation system for steel structures, size effects in concrete structures, the collapse of the I-35W Bridge in Minneapolis, bioinspired design of damage tolerant composites, reliability of microelectromechanical systems (MEMS) devices, structural testing of nanoscale biological and synthetic materials such as collagen fibrils and carbon nanotubes, and multiscale modeling of heterogeneous materials.
R. Ballarini, S.P. Shah and L.M. Keer, "Failure Characteristics of Short Anchor Bolts Embedded in a Brittle Material," Proceedings of the Royal Society of London, A404, pp. 35-54, 1986.
H. Kahn, R. Ballarini, R.L. Mullen and A.H. Heuer, “Electrostatically Actuated Failure of Microfabricated Polysilicon Fracture Mechanics Specimens,” Proceedings of the Royal Society of London, A455, pp. 3807-3823, 1999.
S. Kamat, X. Su, R. Ballarini and A.H. Heuer, “Structural Basis for the Fracture Toughness of the Shell of the Conch Strombus Gigas, Nature, Vol. 405, June 29, pp. 1036-1040, 2000.
H. Kahn, R. Ballarini, J. Bellante and A.H. Heuer, “Fatigue Failure in Polysilicon Not Due to Simple Stress Corrosion,” Science, Vol. 298, pp. 1215-1219, Nov. 8, 2002.
H. Kahn, R. Ballarini and A.H. Heuer, “Mechanical Fatigue of Polysilicon: Effects of Mean Stress and Stress Amplitude,” Acta Materialia, Vol. 54, pp. 667-678, 2006.
S. Eppell, B. Smith, H. Kahn and R. Ballarini, “Nano Measurements With Micro Devices: Mechanical Properties of Hydrated Collagen Fibrils,” Journal of the Royal Society Interface, Vol. 3, pp. 117-121, 2006.
R. Khare, S.L. Mielke, J.T. Paci, S. Zhang, R. Ballarini, G.C. Schatz and T. Belytschko, “Coupled Quantum Mechanical/Molecular Mechanical Modeling of the Fracture of Defective Carbon Nanotubes and Graphene Sheets,” Physical Review B 75, 1 2007.
Z.L. Shen, M.R. Dodge, H. Kahn, R.Ballarini and S.J. Eppell, “Stress-strain Experiments on Individual Collagen Fibrils,” Biophysical Journal, Vol. 95, 2008, 3956-3963.
Y. Tang, R. Ballarini, M.J. Buehler and S.J. Eppell, “Deformation Micromechanisms of Collagen Fibrils Under Uniaxial Tension,” Journal of the Royal Society Interface, Vol. 7, pp. 839-850, 2010 (published first online November 6, 2009, doi: 10.1098/rsif.2009.0390).
Y. Ganesan, Y. Lu, C. Peng, H. Lu, R. Ballarini and J. Lou, “Development and Application of a Novel Micro-fabricated Device for In Situ Tensile Testing of 1-D Nanomaterials,” Journal of Microelectromechanical Systems, Vol. 19, No. 3, pp. 675-682, 2010.
Y. Tang and R. Ballarini, “A Theoretical Analysis of the Breakdown of Electrostrictive Oxide Film on Metal”, Journal of the Mechanics and Physics of Solids, Vol. 59, Issue 2, pp. 178-193, 2011 (published first online doi:10.1016/j.jmps.2010.11.002).
Z.L. Shen, H. Kahn, R. Ballarini and S.J. Eppell, “Viscoelastic Properties of Isolated Collagen Fibrils, Biophysical Journal, Vol. 100, pp. 3008-3014, June 2011.
I. Ostanin, R. Ballarini, D. Potyondy and T. Dumitrica, “A Distinct Element Method for Large Scale Simulations of Carbon Nanotube Assemblies,” Journal of the Mechanics and Physics of Solids, Vol. 61, pp. 762-782, 2013.
D. Giannuzzi, R. Ballarini, A. Huckelbridge, Jr., M. Pollino and M. Valente, “Braced Ductile Shear Panel: a New Seismic Resistant Framing System,” ASCE Journal of Structural Engineering, Vol. 140(2),0401305, 2014.