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CPM Seminar
James Nemes
Mechanical Engineering The dynamic behavior of materials is an area of study with importance to both military and civilian applications. Ballistic penetration, foreign object impact, crashworthiness, and high speed machining are typical examples where knowledge of the strain-rate dependence of materials is critical. In this seminar, experimental techniques to study the dynamic behavior of materials are discussed, with emphasis on the Hopkinson bar. The use of the compression Hopkinson bar to determine parameters in empirical constitutive equations for polycrystalline metals is demonstrated. In addition, a tensile version of the Hopkinson bar, developed at McGill University, will be presented, along with its application to determining the rate dependent response of laminated graphite epoxy. A continuum damage model (CDM) has been utilized to describe the material behavior. A punch version of the Hopkinson bar is utilized to achieve higher strains and strain rates, leading to failure. Finally, current work on the micro mechanical modeling of dual phase steels to understand its rate-dependent behavior is described.
Wednesday, April 17th 2002, 16:00 |