2026-09-22T08:02:28Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/26192 2023-07-10 col_2142_5131 col_2142_14787 com_2142_5130 com_2142_9630 com_2142_234

Sehitoglu, Huseyin Pataky, Garrett J. 2011-08-25T22:18:11Z 2011-08-25T22:18:11Z 2011-08-25T22:18:11Z 2011-08 Crack closure and slip irreversibility in the fatigue crack growth of 316L stainless steel were investigated using digital image correlation (DIC). A polycrystalline and a oriented specimen were tested to study mode I fatigue crack growth, while oriented specimens were used to study mixed mode (I and II) fatigue crack growth. DIC was used to determine the crack growth rates and crack tip displacement fields during the fatigue loading cycles. During this study, a least-squares regression algorithm using the vertical and horizontal displacements was developed, and the stress intensity factors, KI and KII, and the T-stress for the isotropic and anisotropic cases were determined. To further scrutinize the crack closure in both modes I and II, two-point digital extensometers were placed along the crack flanks. Crack opening displacement profiles were used to identify the loads at which each mode opened. The crack closure levels were compared between the polycrystalline and the two oriented specimens. Plastic zones associated with the fatigue crack growth were determined for all specimens using an anisotropic yield criterion. The strains in the plastic zone obtained from digital image correlation were investigated in detail and a dependence on the crystallography and load ratio R was observed. Slip irreversibility in front of the crack tip was measured and showed an increasing trend with increasing crack length; this information is critical for describing the crack growth behavior. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-07-15T12:30:51Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Pataky_Garrett.docx: 21065948 bytes, checksum: 91760ace72c562e356fbde70151ad4c2 (MD5) Pataky_Garrett.pdf: 9157062 bytes, checksum: 4909ec2a268209cb5e518f41a30c019d (MD5) Made available in DSpace on 2011-08-25T22:18:11Z (GMT). No. of bitstreams: 3 Pataky_Garrett.pdf: 3248442 bytes, checksum: a2f69d9d91048c41ffbde08f35303cd5 (MD5) license.txt: 4063 bytes, checksum: 12784acd6ccf4400f8f8571c1d874d39 (MD5) Pataky_Garrett.docx: 21065948 bytes, checksum: 91760ace72c562e356fbde70151ad4c2 (MD5) http://hdl.handle.net/2142/26192 en Copyright 2011 by Garrett James Pataky. All rights reserved. Fatigue Fatigue Crack Growth Crack Closure Mixed Mode Plastic Zones Slip Irreversibility Single Crystals Digital Image Correlation Anisotropy High resolution fatigue crack growth analysis of crack closure and slip irreversibility using digital image correlation Mechanical Sci & Engineering 1917 Mechanical Engineering 0133 University of Illinois at Urbana-Champaign Thesis M.S. PHD:Mechanical Enginerng -UIUC 10KS0133PHD