Eric N Hahn

Los Alamos National Laboratory, Materials Science and Technology, Post-Doc

Followers

Following

Co-author

Public Views

Google Scholar: https://scholar.google.com/citations?user=G7n-pz4AAAAJ&hl=en
ResearchGate: https://www.researchgate.net/profile/Eric_Hahn2
Website: https://sites.google.com/site/ericnhahn/home
Address: 9500 Gilman Drive
Mail Code 0411
La Jolla, CA 92039

less

Jonathan Bowen

London South Bank University

Julita Vassileva

University of Saskatchewan

Cristina Bicchieri

University of Pennsylvania

Maurizio Forte

Duke University

Petra Reinke

University of Virginia

Leticia Cesarino

Universidade Federal de Santa Catarina - UFSC (Federal University of Santa Catarina)

Gerard Lim

Nanyang Technological University

mahmoud hafiz

Al-Azhar University

Martín A. Rodríguez

Universidad Nacional de San Martin

Leonid Borodkin

Lomonosov Moscow State University

Interests

Uploads

Papers by Eric N Hahn

Nature's technical ceramic: the avian eggshell

by Vincent Sherman and Eric N Hahn

Journal of the Royal Society, Interface, 2017

Avian eggshells may break easily when impacted at a localized point; however, they exhibit impres... more Avian eggshells may break easily when impacted at a localized point; however, they exhibit impressive resistance when subjected to a well-distributed compressive load. For example, a common demonstration of material strength is firmly squeezing a chicken egg along its major axis between one's hands without breaking it. This research provides insight into the underlying mechanics by evaluating both macroscopic and microstructural features. Eggs of different size, varying from quail (30 mm) to ostrich (150 mm), are investigated. Compression experiments were conducted along the major axis of the egg using force-distributing rubber cushions between steel plates and the egg. The force at failure increases with egg size, reaching loads upwards of 5000 N for ostrich eggs. The corresponding strength, however, decreases with increasing shell thickness (intimately related to egg size); this is rationalized by a micro-defects model. Failure occurs by axial splitting parallel to the loading...

Grain-size dependent mechanical behavior of nanocrystalline metals

Grain size has a profound effect on the mechanical response of metals. Molecular dynamics continu... more Grain size has a profound effect on the mechanical response of metals. Molecular dynamics continues to expand its range from a handful of atoms to grain sizes up to 50 nm, albeit commonly at strain rates generally upwards of 10 6 s À 1. In this review we examine the most important theories of grain size dependent mechanical behavior pertaining to the nanocrystalline regime. For the sake of clarity, grain sizes d are commonly divided into three regimes: d4 1 μm, 1 μm od o100 nm; and d o100 nm. These different regimes are dominated by different mechanisms of plastic flow initiation. We focus here in the region d o 100 nm, aptly named the nanocrystalline region. An interesting and representative phenomenon at this reduced spatial scale is the inverse Hall–Petch effect observed experimentally and in MD simulations in FCC, BCC, and HCP metals. Significantly, we compare the results of molecular dynamics simulations with analytical models and mechanisms based on the contributions of Conrad and Narayan and Argon and Yip, who attribute the inverse Hall–Petch relationship to the increased contribution of grain-boundary shear as the grain size is reduced. The occurrence of twinning, more prevalent at the high strain rates enabled by shock compression, is evaluated.

Download