2026-09-24T10:28:50Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/16132 2023-07-10 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Made available in DSpace on 2010-05-19T18:38:20Z (GMT). No. of bitstreams: 4 Hernquist_Thesis_opt.pdf: 6706271 bytes, checksum: bed37ee45a2aaa5b5dd1b76036d9d235 (MD5) final thesis.docx: 53203185 bytes, checksum: 4f9e95020501b4b07c3e54b80d49fe55 (MD5) Hernquist_Mark.pdf: 6707593 bytes, checksum: a4d57fd0f2fe93de0b05c567b46559a9 (MD5) license.txt: 4064 bytes, checksum: 734cbea910424fba0018075d1076df24 (MD5) http://hdl.handle.net/2142/16132 en Copyright 2010 Mark W. Hernquist aluminum lithium fracture delamination Effects of crack arresting delaminations in aluminum-lithium alloys Beaudoin, Armand J. Hernquist, Mark W. 2010-05-19T18:38:20Z 2010-05-19T18:38:20Z 2010-05-19T18:38:20Z Aluminum‐lithium alloys have been studied extensively in the last century for their low densities and increased stiffness over conventional high strength aluminum alloys. Combined with cryogenic strength and toughness properties exceeding those at room temperatures, Al‐Li alloys are an appealing choice in astronautics. However, along with these beneficial properties comes a propensity for limited ductility contributing to an unconventional fracture mechanism known as delamination, a secondary fracture along a grain boundary interface similar to the separation within a laminated composite. In this study, mechanical experimentation was coupled with computer simulation to investigate the causes and effects of delaminations occurring along grain boundaries perpendicular to the direction of a Mode I primary crack. Fracture toughness samples were tested with concurrent in situ Digital Image Correlation to obtain a means for validation of the two finite element models. The models were devised to capture the bulk response of the sample immediately prior to and after the delamination event. A crystal plasticity framework with rate‐independent kinematic hardening was then used to determine the local behavior of the crystallographic orientations prone to delamination. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2010-02-25T14:14:52Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 final thesis.docx: 53203185 bytes, checksum: 4f9e95020501b4b07c3e54b80d49fe55 (MD5) Hernquist_Thesis_opt.pdf: 6706271 bytes, checksum: bed37ee45a2aaa5b5dd1b76036d9d235 (MD5) 2010-5 University of Illinois at Urbana-Champaign Mechanical Sci & Engineering 1917 Mechanical Engineering 0133 Thesis M.S. MS:BS/MS Mechanical Engr -UIUC 10KS4018MS