Mid-West Mechanics Seminar

Date/Time:	Wednesday, 15 Sep 2010 at 1:10 pm
Location:	Auditorium, Howe Hall
Cost:	Free
Contact:	Mary Frommelt
Phone:	515-294-5666
Channel:	College of Engineering
Categories:	Lectures
Actions:	Download iCal/vCal | Email Reminder

"Size Dependence of Strength of Metals," presented by William Nix, Stanford University. This is part of the Mid-West Mechanics Seminars series.

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For more than 350 years, the design of mechanical structures has been based on the principle that the strength of materials is independent of the size of the specimen. But now, as mechanical structures and devices are being created on a smaller and smaller scale, we are finding that this basic principle is beginning to break down. We are finding that "smaller is stronger."

The mechanics community, in strong collaboration with the materials community, has contributed significantly to understanding some of these effects through the development of strain gradient plasticity. But now, within the past half-decade, we are finding that the strength of metal crystals is size dependent even in the absence of strain gradients. Here we show that these size effects begin to arise when the specimen size approaches the spacing between dislocations, in the few micrometer regime, and becomes even more pronounced when the specimen size is much less that the dislocation spacing, in the sub-micrometer regime.