Page 46 - ASME_IMECE_2019_Program

Track 10: Advanced Materials: Design,
Processing, Characterization and
Applications
10-31-2: ADVANCED MATERIALS: DESIGN,
PROCESSING, CHARACTERIZATION AND
APPLICATIONS
Wednesday, November 13, 9:45AM–10:30AM
Room 155F, plasticity. She is an editor for Acta Materialia and Scripta
Calvin L. Rampton Salt Palace Convention Center
Material and Microstructural Features That Prompt
Sub-Crystalline Localization in Polycrystalline High-
Performance Alloys
(IMECE2019-14005)
Irene J. Beyerlein
University of California, Santa Barbara
Abstract: Improved prediction of the behavior of materials
under the complex loading conditions encountered in structural
components is critical to ensure reliable, long-term performance
and to guide the design of new materials along high controlled
processing paths. However, a major challenge for structural
materials is the strong dependence of the intrinsic plastic
deformation processes on material structure, with important
features at the nanoscale, microscale, and mm-scale in most
classes of metallic materials. Deformation processes are
typically highly heterogeneous, propagating through complex
microstructure-dominated networks, ultimately resulting in
local damage and failure of the part. Cyclic and monotonic
loading are performed on a number of high-performance alloys,
such as high strength titanium aerospace alloy and Ni-based
superalloys. Using a combination of in situ deformation
DIC and synchrotron measurements, 3D microstructural
characterization, and 3D crystal plasticity based computational
modeling, we investigate the micromechanical and
microstructural factors leading to strain localization and
subsequent slip band initiation. This suite of techniques
altogether enables full-field measurement and modeling of the
plastic and elastic field at the surface and in the bulk of the
specimen. The analysis focuses on the coupled role of elastic
anisotropy, grain neighborhoods, and grain shape and size in
determining the location of the exceptionally preferred points
of high elastic strain concentration and localized slip, when the
applied strain is under but near the macroscopic elastic-plastic
transition. We find that the very few localized slip bands are
correlated with the development of only the highest elastic
strain concentrations. Strain localization is specifically favored
in crystals that have an outstandingly compliant orientation
relative to all its neighbors and a non-equiaxed shape with
sharp corners. These results explain that the presence of
annealing twins in the microstructure significantly increases
the probability of localization.
xliv Bio: Irene J. Beyerlein is a professor at the University of
California, Santa Barbara with a joint appointment in the
Mechanical Engineering and Materials Departments. After
receiving her Ph.D. degree in Theoretical and Applied Mechanics
at Cornell University in 1997, she began a postdoctoral
appointment as a J.R. Oppenheimer Fellow at Los Alamos
National Laboratory, where she remained on the scientific staff
in the Theoretical Division, until 2016. She has published one
book, nine book chapters, and more than 290 peer-reviewed
articles in the field of structural composites, materials
processing, multiscale modeling of microstructure/property
relationships, deformation mechanisms, and polycrystalline
Materialia and an associate editor for Modelling and Simulation
in Materials Science and Engineering. In recent years, she has
been awarded the Los Alamos National Laboratory Fellow’s
Prize for Research (2012), the International Plasticity
Young Researcher Award (2013), the TMS Distinguished
Scientist/Engineering Award (2018), and the Brimacombe
Metal (2019).
Track 11: Mechanics of Solids, Structures
and Fluids
11-49-1: MECHANICS OF SOLIDS, STRUCTURES
AND FLUIDS
Monday, November 11, 9:45AM–10:30AM
Room 255B,
Calvin L. Rampton Salt Palace Convention Center
Getting Stuck and Breaking Free: Adhesion, Friction,
Strength, and Toughness
(IMECE2019-14006)
Kaushik Bhattacharya
California Institute of Technology
Abstract: Many phenomena of scientific and technological
interest are described by the evolution of free boundaries or
free discontinuities. Examples include the peel front while
peeling an adhesive tape, the rupture front of earthquakes,
dislocations in solids, and the crack set during fracture. This
evolution takes place in a heterogeneous medium where the
length scale of the heterogeneities are much smaller than the
length scale of interest. In such situations, it is natural to seek
the overall or effective behavior at the scale of interest. This
effective behavior is not characterized by averaging, but
instead dominated by critical events. Thus, the effective
behavior can be qualitatively different from the local behavior.
This makes such problems difficult to study, but also offers
opportunities for exploiting heterogeneities to dramatically
material properties. This talk will discuss the underlying issues
with examples drawn from fracture, friction, dislocation
dynamics, phase boundary propagation, and peeling of
adhesive tape.
Bio: Kaushik Bhattacharya is Howell N. Tyson, Sr., Professor of
Mechanics and Professor of Materials Science as well. He
received his B.Tech. degree from the Indian Institute of
Technology, Madras, India in 1986, his Ph.D. from the
University of Minnesota in 1991, and his post-doctoral training