Title page for ETD etd-3753128097370


Type of Document Master's Thesis
Author Stevens, John Boyet
URN etd-3753128097370
Title Finite Element Analysis of Adiabatic Shear Bands in Impact and Penetration Problems
Degree Master of Science
Department Engineering Science and Mechanics
Advisory Committee
Advisor Name Title
Romesh C. Batra Committee Chair
Ronald D. Kriz Committee Co-Chair
Werner Kohler none
Keywords
  • taylor impact test
  • ballistic
  • simulation
  • localization
Date of Defense 1996-11-22
Availability unrestricted
Abstract

We study axisymmetric deformations of

depleted uranium (DU) and tungsten heavy

alloy (WHA) rods impacting at normal

incidence both a rigid, planar target and a

thick, deformable steel target. Each

deformable material is modeled as elastic

thermoviscoplastic; the flow stress increases

with an increase in the effective plastic strain

and effective plastic strain-rate but decreases

with a rise in the temperature. An objective

of this work is to ascertain when and where a

shear band, defined as a narrow region of

rapid, intense plastic deformation, forms in

each material subject to impact loading. The

Taylor impact simulations show that shear

bands form earlier in WHA than in DU for

the material parameters used. In the

penetration simulations, shear bands form

continuously in the ejecta of the DU

penetrator while only one shear band occurs

in the WHA ejecta followed by more uniform

deformations. Note: In order to view the

computer animations referenced in this thesis,

one must have a QuickTime movie player

and download the files named Ujce.mov

Uz2e.mov Uz3e.mov Wjce.mov Wz2e.mov

and Wz3e.mov from the same directory the

"pdf" file resides in.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  stevens.pdf 2.88 Mb 00:13:21 00:06:51 00:06:00 00:03:00 00:00:15
  Ujce.mov 3.93 Mb 00:18:11 00:09:21 00:08:11 00:04:05 00:00:20
  Uz2e.mov 3.87 Mb 00:17:54 00:09:12 00:08:03 00:04:01 00:00:20
  Uz3e.mov 4.19 Mb 00:19:24 00:09:58 00:08:44 00:04:22 00:00:22
  Wjce.mov 3.97 Mb 00:18:22 00:09:27 00:08:16 00:04:08 00:00:21
  Wz2e.mov 2.96 Mb 00:13:41 00:07:02 00:06:09 00:03:04 00:00:15
  Wz3e.mov 1.48 Mb 00:06:52 00:03:32 00:03:05 00:01:32 00:00:07

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