{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/114050"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/114050","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Failure mechanisms of dielectric materials for electric motors","abstract":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-12-01","abstract_html":"Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-12-01","abstract_has_math":false,"creators":["Arastu, Faraz"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Materials Science & Engr","degree_department":null,"school":null,"contributors":["Lyding, Joseph","Krogstad, Jessica","Schleife, Andre","Bellon, Pascal"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022-04-29T21:58:17Z","date_published":"2022-04-29T21:58:17Z","updated_at":"2026-07-22T22:24:54Z","subjects":["Materials science"],"languages":["en","eng"],"rights":["Copyright 2021 Faraz Arastu"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/114050","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Lyding, Joseph","Krogstad, Jessica","Schleife, Andre","Bellon, Pascal"]},{"key":"dc:creator","label":"Author","values":["Arastu, Faraz"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2022-04-29T21:58:17Z","2024-04-29T21:58:46Z","2021-12","2021-10-28"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science & Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"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":["Materials science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en","eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2021 Faraz Arastu"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/114050"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-12-01","The student, Faraz Arastu, accepted the attached license on 2021-10-22 at 14:40.","The student, Faraz Arastu, submitted this Thesis for approval on 2021-10-22 at 14:43.","This Thesis was approved for publication on 2021-10-28 at 13:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #17170 on 2022-04-29 at 16:09:09","Made available in DSpace on 2022-04-29T21:58:17Z (GMT). No. of bitstreams: 2 ARASTU-THESIS-2021.pdf: 2877851 bytes, checksum: c4d7fe5662acfc77a59574b92323c3dc (MD5) LICENSE.txt: 4209 bytes, checksum: 26041249921f4f790b941f8172611802 (MD5) Previous issue date: 2021-10-28","Embargo set by: Seth Robbins for item 123415 Lift date: 2024-04-29T21:58:46Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited","Recent trends in electrification have increased demand for advanced sensors and actuators in the transportation and power systems industries. Complex thermomechanical systems used in geothermal energy, industrial gas turbines, aircraft propulsion systems, and spacecraft power systems require high power density devices that generate large amounts of heat in a smaller form factor. The community has looked to high critical flux cooling technology as well as higher-temperature materials development to address these needs. However, the development of high-temperature actuators, like electric motors, has lagged behind the development of high-temperature sensors and circuitry. This study explores the thermal operating limits of electric motor insulation to develop design and downselection criteria for developing high-temperature insulation materials that will meet the demands for high power density in industrial applications. A preceramic resin, polymethylsilsesquioxane, is first used to demonstrate that motor insulation can operate up to 660◦C with a dielectric strength of 162 VRMS, outperforming the stateof-the-art ML240 insulation commonly used in commercial motors. Then, insulation materials spanning a range of chemical structure motifs are used to build electric motor prototypes to determine the excitation current, force, and temperature windows in which each material can operate at the device level. Surprisingly, devices made with ML240 insulation - which has a 663◦C lower intrinsic thermal stability than ceramawire insulation - outperform ceramawire devices by nearly 60◦C. An investigation of the underlying failure mechanisms of the insulation was conducted to explain this result, revealing that thermal expansion-induced mechanical stresses dominate over intrinsic thermal stability in determining the critical failure temperature of a device. To account for these stresses in the development of new, high-temperature insulation materials, a thermal expansion model is developed to downselect materials based on their thermomechanical properties and predict their device-level performance without building experimental device prototypes. This model can be used by both materials scientists and motor engineers to tailor the operating temperature window of film-insulation materials and meet the thermal requirements of a given application."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Failure mechanisms of dielectric materials for electric motors"]}]}],"canonical_facts":{"dc:contributor":["Lyding, Joseph","Krogstad, Jessica","Schleife, Andre","Bellon, Pascal"],"dc:creator":["Arastu, Faraz"],"dc:date":["2022-04-29T21:58:17Z","2024-04-29T21:58:46Z","2021-12","2021-10-28"],"dc:description":["Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-12-01","The student, Faraz Arastu, accepted the attached license on 2021-10-22 at 14:40.","The student, Faraz Arastu, submitted this Thesis for approval on 2021-10-22 at 14:43.","This Thesis was approved for publication on 2021-10-28 at 13:03.","DSpace SAF Submission Ingestion Package generated from Vireo submission #17170 on 2022-04-29 at 16:09:09","Made available in DSpace on 2022-04-29T21:58:17Z (GMT). No. of bitstreams: 2 ARASTU-THESIS-2021.pdf: 2877851 bytes, checksum: c4d7fe5662acfc77a59574b92323c3dc (MD5) LICENSE.txt: 4209 bytes, checksum: 26041249921f4f790b941f8172611802 (MD5) Previous issue date: 2021-10-28","Embargo set by: Seth Robbins for item 123415 Lift date: 2024-04-29T21:58:46Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system","Author requested closed access (OA after 2yrs) in Vireo ETD system","Limited","Recent trends in electrification have increased demand for advanced sensors and actuators in the transportation and power systems industries. Complex thermomechanical systems used in geothermal energy, industrial gas turbines, aircraft propulsion systems, and spacecraft power systems require high power density devices that generate large amounts of heat in a smaller form factor. The community has looked to high critical flux cooling technology as well as higher-temperature materials development to address these needs. However, the development of high-temperature actuators, like electric motors, has lagged behind the development of high-temperature sensors and circuitry. This study explores the thermal operating limits of electric motor insulation to develop design and downselection criteria for developing high-temperature insulation materials that will meet the demands for high power density in industrial applications. A preceramic resin, polymethylsilsesquioxane, is first used to demonstrate that motor insulation can operate up to 660◦C with a dielectric strength of 162 VRMS, outperforming the stateof-the-art ML240 insulation commonly used in commercial motors. Then, insulation materials spanning a range of chemical structure motifs are used to build electric motor prototypes to determine the excitation current, force, and temperature windows in which each material can operate at the device level. Surprisingly, devices made with ML240 insulation - which has a 663◦C lower intrinsic thermal stability than ceramawire insulation - outperform ceramawire devices by nearly 60◦C. An investigation of the underlying failure mechanisms of the insulation was conducted to explain this result, revealing that thermal expansion-induced mechanical stresses dominate over intrinsic thermal stability in determining the critical failure temperature of a device. To account for these stresses in the development of new, high-temperature insulation materials, a thermal expansion model is developed to downselect materials based on their thermomechanical properties and predict their device-level performance without building experimental device prototypes. This model can be used by both materials scientists and motor engineers to tailor the operating temperature window of film-insulation materials and meet the thermal requirements of a given application."],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/114050"],"dc:language":["en","eng"],"dc:rights":["Copyright 2021 Faraz Arastu"],"dc:subject":["Materials science"],"dc:title":["Failure mechanisms of dielectric materials for electric motors"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Materials Science & Engr"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["M.S."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:54Z"}