Conferences, Lectures, & Seminars
Events for January
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AME Department Seminar
Wed, Jan 18, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Prof. Andrea M. Hodge, Department of Aerospace & Mechanical Engineering, University of Southern California, Los Angeles, CA 90089, USA
Talk Title: The Search for Stable Nanostructured Materials
Abstract: Highly nanotwinned (nt) metals have shown a strength comparable to nanocrystalline metals, while maintaining other desired properties including ductility, conductivity, and thermal stability. However, the deformation mechanisms and mechanical stability of the nt metals is not yet fully understood. Therefore in this presentation, results from highly aligned nt-Cu samples tested in compression, torsion, and tension under various loading/testing conditions relative to the twin boundary (TB) direction will be presented. The microstructures of the tested samples were analyzed before and after deformation for each loading configuration in order to study the stability of the nanotwins.
In all testing configurations, the nt structure was observed to be mostly stable, in which, to a significant extent, the nanotwins survived without major changes in twin size, orientation, or twin density. However, distinct differences in the overall deformation of the samples and in the extent of the changes were observed. Elevated temperature stability will also be discussed.
More Info: http://ae-www.usc.edu/seminars/index.shtml#upcomingLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ae-www.usc.edu/seminars/index.shtml#upcoming
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AME Department Seminar
Wed, Jan 25, 2012 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Rouslan Krechetnikov, Assistant Professor. Department of Mechanical Engineering. University of California, Santa Barbara
Talk Title: On a few puzzles in interfacial fluid mechanics
Abstract: Interfacial fluid mechanics has always been an inexhaustible source of challenging questions. In this talk I will discuss three long-standing problems and our recent progress on their understanding. First, I will present the experiments on self-agitation of a pendant drop, which results from a chemical reaction at the drop interface and which generates a number of nontrivial features: nonlinear auto-oscillations, tip-streaming and droplet trajectory splitting. While some of these features are analogous to the ones in the Taylor cone problem, preliminary analysis revealed that the underlying physics is fundamentally different. The second problem addresses the controversy in the current understanding of Marangoni effects in the classical Landau-Levich problem of a film deposition by a substrate withdrawal. The talk concludes with a discussion of the nature of the crown forming instability in the drop splash problem. Namely, I will describe some recent experiments on the drop splash problem, in which a drop impinges on a thin film of the same liquid, and provide some novel theoretical insights into the nature of the fundamental instability responsible for the crown formation.
Host: Prof. Paul Newton
More Info: http://ae-www.usc.edu/seminars/index.shtml#upcomingLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ae-www.usc.edu/seminars/index.shtml#upcoming
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AME Department Seminar
Fri, Jan 27, 2012 @ 11:00 AM - 12:00 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Speaker: Panos Papadopoulos, Professor. Department of Mechanical Engineering. University of California, Berkeley Berkeley, CA 94720-1740.
Talk Title: Multiscale Modeling of Phase Transition in Superelastic Nitinol Polycrystals
Abstract: Nitinol is a Ni-Ti alloy used widely in biomedical devices, such as endovascular stents, angioplasty guidewires, vena-cava filters, etc. One of the major attractions of Nitinol as a biomedical material is its superelastic behavior. This is due to a stress-induced solid- solid phase transformation which accommodates large deformations that may be completely reversed upon removal of the stress. Most constitutive models of phase transformation in superelastic Nitinol account for the austenite-martensite transformation only, and disregard the formation of an intermediate rhombohedral phase (R-phase). However, the presence of R-phase influences the formation of martensitic variants, thus rendering the transformation process path-dependent. In this seminar, a path-dependent micromechanics-based model that incorporates all possible transformations is presented first for the stress-induced phase transformation of Nitinol single crystals. This is subsequently extended to a multiscale thermomechanical model which accounts for the presence of polycrystalline texture. An efficient numerical strategy for solving the resulting constitutive equations is also proposed within a finite element setting.
Host: Prof. Geoff Spedding
More Info: http://ae-www.usc.edu/seminars/index.shtml#upcomingLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: April Mundy
Event Link: http://ae-www.usc.edu/seminars/index.shtml#upcoming