{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/71129"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/71129","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Temperature and Axial Strain Rate Effects on Micromechanical Behavior in Triaxially Compressed Marbles","abstract":"A series of high resolution, simultaneous stress-axial strain, volumetric strain, and acoustic emission measurements were used to survey the effects of temperature (T) and axial strain rate ((epsilon)) variations on micromechanical behavior in triaxially compressed marbles. Thirty-five tests were run on low porosity, homogeneous marble samples with relatively uniform calcite grain sizes (0.23, 0.50, and 1.90mm), at pressures (P) of 0.75, 1.375, and 2kb, temperatures of 30, 100, and 200(DEGREES)C, and computer-controlled strain rates of 10('-4), 10('-5), and 10('-6)/sec.","abstract_html":"A series of high resolution, simultaneous stress-axial strain, volumetric strain, and acoustic emission measurements were used to survey the effects of temperature (T) and axial strain rate ((epsilon)) variations on micromechanical behavior in triaxially compressed marbles. Thirty-five tests were run on low porosity, homogeneous marble samples with relatively uniform calcite grain sizes (0.23, 0.50, and 1.90mm), at pressures (P) of 0.75, 1.375, and 2kb, temperatures of 30, 100, and 200(DEGREES)C, and computer-controlled strain rates of 10('-4), 10('-5), and 10('-6)/sec.","abstract_has_math":false,"creators":["Schrodt, Joseph Keith"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Geology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-16T06:06:38Z","date_published":"2014-12-16T06:06:38Z","updated_at":"2026-07-22T22:26:04Z","subjects":["Geology"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8324638"],"render_values":[{"text":"(UMI)AAI8324638","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/71129","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Schrodt, Joseph Keith"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-16T06:06:38Z","10000-01-01","1983"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Geology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Geology"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/71129","(UMI)AAI8324638"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["A series of high resolution, simultaneous stress-axial strain, volumetric strain, and acoustic emission measurements were used to survey the effects of temperature (T) and axial strain rate ((epsilon)) variations on micromechanical behavior in triaxially compressed marbles. Thirty-five tests were run on low porosity, homogeneous marble samples with relatively uniform calcite grain sizes (0.23, 0.50, and 1.90mm), at pressures (P) of 0.75, 1.375, and 2kb, temperatures of 30, 100, and 200(DEGREES)C, and computer-controlled strain rates of 10('-4), 10('-5), and 10('-6)/sec.","A d('- 1/2) grain diameter dependence of the yield stress ((sigma)(,y)) and onset of dilatancy (C') over most of the T/(epsilon)/P conditions and analysis of individual AE signal patterns, was consistent with an association of (sigma)(,y) with an acceleration in twinning and related microcrack nucleation, and of C' with inter- and/or transgranular cracking. At elevated T, decreases in (sigma)(,y) and C' were attributed to thermally induced microcrack activity, and after C', regions of unstable crack growth alternated with periods of crack stability. The amount of dilatancy decreased with T due to plastic activity at crack tips. At high P and/or high T, dilatancy was suppressed and post-yield pore collapse led to accelerated negative volume change.","Crack nucleation and growth in coarser grain marbles and grain boundary sliding in finer grain marbles were enhanced at lower (epsilon). Increases in (epsilon) or T reduced the pressures at which transitions between spontaneous, unstable, and stable crack growth occurred.","The contribution of dilatancy or compaction generated work done on the confining fluid pressure was removed from the observed stress-axial strain curves. A peak stress was observed in the corrected ((sigma)(,w) versus (epsilon)) curves for larger grain size samples deformed at room T and high P. The peak was followed by a brief period of work softening and a subsequent hardening region. The trend toward the occurrence of a peak stress was enhanced with temperature and pressure and the slope of the post-peak hardening region was relatively temperature independent. Similar observations in other systems have been modelled by dislocation multiplication processes.","Made available in DSpace on 2014-12-16T06:06:38Z (GMT). No. of bitstreams: 1 8324638.pdf: 4142276 bytes, checksum: 3bbf2d1267dfa0a5934488eeebe34b3c (MD5) Previous issue date: 1983","Embargo set by: Seth Robbins for item 71295 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","166 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983."]},{"key":"dc:title","label":"Title","values":["Temperature and Axial Strain Rate Effects on Micromechanical Behavior in Triaxially Compressed Marbles"]}]}],"canonical_facts":{"dc:creator":["Schrodt, Joseph Keith"],"dc:date":["2014-12-16T06:06:38Z","10000-01-01","1983"],"dc:description":["A series of high resolution, simultaneous stress-axial strain, volumetric strain, and acoustic emission measurements were used to survey the effects of temperature (T) and axial strain rate ((epsilon)) variations on micromechanical behavior in triaxially compressed marbles. Thirty-five tests were run on low porosity, homogeneous marble samples with relatively uniform calcite grain sizes (0.23, 0.50, and 1.90mm), at pressures (P) of 0.75, 1.375, and 2kb, temperatures of 30, 100, and 200(DEGREES)C, and computer-controlled strain rates of 10('-4), 10('-5), and 10('-6)/sec.","A d('- 1/2) grain diameter dependence of the yield stress ((sigma)(,y)) and onset of dilatancy (C') over most of the T/(epsilon)/P conditions and analysis of individual AE signal patterns, was consistent with an association of (sigma)(,y) with an acceleration in twinning and related microcrack nucleation, and of C' with inter- and/or transgranular cracking. At elevated T, decreases in (sigma)(,y) and C' were attributed to thermally induced microcrack activity, and after C', regions of unstable crack growth alternated with periods of crack stability. The amount of dilatancy decreased with T due to plastic activity at crack tips. At high P and/or high T, dilatancy was suppressed and post-yield pore collapse led to accelerated negative volume change.","Crack nucleation and growth in coarser grain marbles and grain boundary sliding in finer grain marbles were enhanced at lower (epsilon). Increases in (epsilon) or T reduced the pressures at which transitions between spontaneous, unstable, and stable crack growth occurred.","The contribution of dilatancy or compaction generated work done on the confining fluid pressure was removed from the observed stress-axial strain curves. A peak stress was observed in the corrected ((sigma)(,w) versus (epsilon)) curves for larger grain size samples deformed at room T and high P. The peak was followed by a brief period of work softening and a subsequent hardening region. The trend toward the occurrence of a peak stress was enhanced with temperature and pressure and the slope of the post-peak hardening region was relatively temperature independent. Similar observations in other systems have been modelled by dislocation multiplication processes.","Made available in DSpace on 2014-12-16T06:06:38Z (GMT). No. of bitstreams: 1 8324638.pdf: 4142276 bytes, checksum: 3bbf2d1267dfa0a5934488eeebe34b3c (MD5) Previous issue date: 1983","Embargo set by: Seth Robbins for item 71295 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","166 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983."],"dc:identifier":["http://hdl.handle.net/2142/71129","(UMI)AAI8324638"],"dc:subject":["Geology"],"dc:title":["Temperature and Axial Strain Rate Effects on Micromechanical Behavior in Triaxially Compressed Marbles"],"dc:type":["text"],"thesis:degree_discipline":["Geology"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:04Z"}