MATERIALS SCIENCE AND ENGINEERING

DMSE Colloquia, Fall 2009

Tuesday, November 03, 2009 | 10:00 AM | 411 White Building

This talk has been canceled!

Plate Impact Experiments: Probing the Limits of Material Behavior

Vikas Prakash

Department of Mechanical and Aerospace Engineering
Case Western Reserve University
Cleveland, OH 44106-7204
U.S.A.

Abstract:

This talk has been canceled!
Professor Prakash's group conducts research on the mechanical response of materials subjected to very high loading rates. This research is motivated by the need for better understanding of such processes as shear band formation, micro-cracking and fragmentation, dynamic spall and fracture, high-speed frictional slip, design of energy absorbing materials/structures, high speed machining, friction stir welding, to name a few. The research involves combined experimental and theoretical investigations in which the experimental component makes use of plane wave loading to provide the most direct interpretation of the experimental results in terms of the response of the material. Plane waves are generated in a plate impact facility, which is designed to produce the impact of parallel plates. In order to subject the impacting plates to combined pressure and shear loading, the impacting plates are inclined relative to the direction of approach. The motion of the rear surface of the impacted plate is recorded using a variety of laser interferometers. Studies have been conducted on a wide variety of materials including metals, metal alloys, glasses, ceramics, bulk metallic glass, polymers, glass-fiber reinforced polymer composites, and geo-materials. In addition, studies have been conducted on the dynamic friction of sliding interfaces operating under extreme conditions, such as the interface between a machine tool and the stock being machined or welded, and geo-material interfaces of importance to earthquake fault dynamics. Experiments can also be conducted in a so-called "soft recovery" configuration in which the specimen is recovered after being subjected to a single plane pulse -- thereby making it possible to relate the dislocation motion or micro-cracking and/or damage that occurred to the action of a known stress pulse. The talk will highlight some of the interesting results and insights gained from these studies.

Coffee and doughnuts will be served from 9:30 AM.

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