Special MS&E Colloquium with Dr. Geng Feng
Date: March 10, 2008 from 3:00 pm to 4:00 pm EDT
Location: 214 S. W. Mudd
Contact: For further information regarding this event, please contact Chad Gurley by sending email to cg2029@columbia.edu .
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Dr. Geng Feng
Postdoctoral Fellow
Brown University

Nanomechanical Characterization and Modeling

Nanomechanical characterization is of central significance for the emerging applications of nanomaterials and most biomaterials. Because states of stress and deformation are rarely uniform when materials are probed at this scale, the interpretation of observations generally relies on theoretical modeling to achieve a full understanding of the quantitative relationships between the measurements and the fundamental material properties.

In this lecture, I will focus on a specific nanomechanical characterization technique-nanoindentation and the related theoretical modeling. Nanoindentation is a useful tool to deform, manipulate, and visualize materials at small scales. The excellent control and measurement capabilities of the nanoindenter will be demonstrated in the following studies: a study on the mechanical properties of nanowires, a study on the size-dependence of mechanical properties, and a study on the time-dependent deformation at the nanometer scale. Moreover, in order to predict the contact-induced phenomena at small scales, such as plasticity and fracture, it is important to know the stress distribution around an elastoplastic contact, which is also a classical contact mechanics problem with great practical and theoretical interests; I will provide an approximate closed-form analytical solution for the stress distribution, which is in close agreement with finite element analysis.

Hosted by MS&E Faculty.