
- Graduate Field Affiliations
- Aerospace Engineering
- Mechanical Engineering
- Theoretical and Applied Mechanics
Biography
Alan Zehnder received his doctorate in mechanical engineering with a minor in materials science from the California Institute of Technology. He stayed on as a postdoctoral research fellow for one year, and joined the Cornell faculty in 1988. In 1993 he was the faculty member in residence in Hamburg, Germany, for the Cornell Engineering Abroad program. He was a visiting Professor at Caltech in the 1996-97 academic year. In summer of 1998 he served as a Senior Faculty Fellow at the Naval Surface Warfare Center in Carderock, Maryland. In 2004 he was a Guest Professor at the Vienna University of Technology. He currently serves as Associate Dean for Undergraduate Programs and has also served as Associate Dean for Diversity and Faculty Development in the College of Engineering. Zehnder is a member of the American Society of Mechanical Engineers, and the Society for Experiment Mechanics.
Research Interests
Zehnder’s research focuses on the fracture of nanoscale systems, nonlinear dynamics of nanomechanical oscillators, damage tolerance of polymers and matrix composites.
Nanoscale systems show surprising effects due to their small size, low damping, interaction with light and other effects. A rich range of behaviors such as sub and super-harmonic entrainment and wide tunability have been discovered in nano-scale beams undergoing CW laser driven limit cycle oscillations. Recent work focuses on the behavior of coupled systems of nano-scale oscillators.
Nanoscale structures can have strengths close to the theoretical strength of the material. In such structures the only “defect” is often roughness or oxidation on the surface. Research is underway to fully explore the effects of surfaces on the strength of nano-scale systems and to design tactics for improving their strength.
Composite laminated are well known for their high specific strength and stiffness. Recent work focuses on damage and damage tolerance of sandwich structures and degradation of polyimides exposed to high temperature and moisture.
Please see Zehnder’s group website for additional information and links to publications.
- Computational Solid Mechanics
- Energy Systems
- Materials Design
- Micro Nano Systems
- Nanotechnology
- Solid Mechanics
- Wind Energy
- Advanced Manufacturing and Materials
Teaching Interests
My undergraduate teaching interests are in engineering mechanics and materials, and engineering mathematics. At the graduate level I teach solid mechanics and fracture mechanics
Select Publications
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A. Bhaskar, M. Walth, R. H. Rand and A. T. Zehnder, “Synchronization in Pairs of Opto-Thermally Driven Mechanically Coupled Micro-Oscillators,” Journal of Microelectromechanical Systems, 32(1), 136-142 (2023).
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Jikun Wang, Kunpeng Cui, Bangguo Zhu, Jian Ping Gong, Chung-Yuen Hui, Alan T. Zehnder, “Load transfer between permanent and dynamic networks due to stress gradients in nonlinear viscoelastic hydrogels,” Extreme Mechanics Letters, 58, 101928 (2023).
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A. Bhaskar, M. Walth, R. H. Rand and A. T. Zehnder, “Bistability in Coupled Opto-Thermal Micro-Oscillators,” Journal of Microelectromechanical Systems (2022).
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Jikun Wang, Tianjiao Lia, Fan Cui, Chung-Yuen Hui, Jingjie Yeo, Alan T. Zehnder, “Metamodeling of Constitutive Model Using Gaussian Process Machine Learning,” Journal of the Mechanics and Physics of Solids, 154, 104532 (2021)
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Zezhou Liu, Michael Zakoworotny, Jingyi Guo Alan Zehnder, Chung-Yuen Hui, “Energy release rate of a single edge cracked specimen subjected to large deformation,” International Journal of Fracture, 226, 71-79 (2020).
Select Awards and Honors
- Sia Nemat-Nasser Award and Medal, Society for Experimental Mechanics 2021
- Fellow, Society for Experimental Mechanics (SEM) 2019
- Dennis G. Shepherd Teaching Award, College of Engineering, Cornell University 2018
- Fellow, American Society of Mechanical Engineers 2013
- Rudolf Kingslake Medal and Prize, Society of Photographic Instrumentation Engineers 1988
- Charles Lee Powell Fellow 1985
- TRW Advanced Technologies Fellow 1984
Education
- B.S., Mechanical Engineering, University of California-Berkeley 1982
- M.S., Mechanical Engineering, California Institute of Technology 1983
- Ph.D., Mechanical Engineering, California Institute of Technology 1987