Title Information
Title
Pressure-Shear Plate Impact Experiments on High-Purity Aluminum at Temperatures Approaching Melt
Name: Personal
Name Part
Grunschel, Stephen E.
Role
Role Term: Text
creator
Origin Information
Copyright Date (keyDate="yes", encoding="w3cdtf")
2009
Physical Description
Extent
21, 163 p.
digitalOrigin
born digital
Note
Thesis (Ph.D.) -- Brown University (2009)
Name: Personal
Name Part
Clifton, Rodney
Role
Role Term: Text
director
Name: Personal
Name Part
Kim, Kyung-Suk
Role
Role Term: Text
reader
Name: Personal
Name Part
Briant, Clyde
Role
Role Term: Text
reader
Name: Corporate
Name Part
Brown University. Division of Engineering. Mechanics of Solids
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
High-temperature, pressure-shear plate impact experiments were conducted in order to measure the plastic response of high-purity aluminum at high strain rates (106 s-1) and at temperatures approaching melt. In similar experiments by Frutschy and Clifton (JMPS 46, 1998, 1723-1743) on OFHC copper, the flow stress decreases with increasing temperature and increases with increasing strain rate over the full range of temperatures and strain rates examined. No conclusive evidence of a change in rate-controlling mechanism was obtained. In the current study, temperatures that are larger fractions of the melting temperature were accessible because of the lower melting point of aluminum. Because the melting temperature of aluminum is pressure dependent, and a typical pressure-shear plate impact experiment subjects the sample to large pressures (2 GPa ? 7 GPa), a pressure-release type experiment was used to reduce the pressure in order to measure the shearing resistance at temperatures up to 95% of the current melting temperature. Again, no conclusive evidence of a change in rate-controlling mechanism was obtained. The measured shearing resistance was remarkably large (~50 MPa at a shear strain of 2.5) for temperatures this near melt. Numerical simulations of the high-temperature plate impact experiments show that heat conduction can affect the sample temperature significantly, despite the short duration of the test (~2 µs). Simulations conducted using a version of the Nemat-Nasser/Isaacs constitutive equation (Acta Materialia 45(3), 1997, 907-919), modified to model the mechanism of geometric softening, appears to capture adequately the hardening/softening behavior observed experimentally.
Subject (Local)
Topic
high-temperature
Subject (Local)
Topic
high strain-rate
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/806262")
Topic
Aluminum
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/956494")
Topic
High temperatures
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20091218
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0S180XP
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In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations