Presently there is a lack of confidence amongst engineers when specifying the preload of a mechanical fastener in a composite joint due to a lack of a fundamental knowledge base regarding the behavior of composites under fastener compressive load. As such, a novel experimental procedure was developed herein to determine the through-the-thickness compressive (TTTC) material properties. A total of 206 property tests were performed on four different graphite/epoxy material systems. The results confirmed that TTTC material properties vary with fiber orientation, laminate thickness, fiber volume fraction, and even laminate surface finish. Hence, the 'rule of mixtures' provides a poor estimate of the TTTC modulus in that it fails to account for any of these variables.
Finally, acoustic emission nondestructive testing, along with a modified approach to MSFC-STD-486B, Torque Limits for Standard Threaded Fastener, were used to determine the torque limit of a fastener in a single lap joint. The laminate configuration examined in these tests was manufactured in accordance with the MIL-HDBK-17 design code. The results demonstrated the inability of the fasteners employed to damage the one composite system investigated: fastener thread failure occurred first. Further study is necessary to confirm or refute these results for other composite systems and joint configurations.
","abstract_html":"<p>Presently there is a lack of confidence amongst engineers when specifying the preload of a mechanical fastener in a composite joint due to a lack of a fundamental knowledge base regarding the behavior of composites under fastener compressive load. As such, a novel experimental procedure was developed herein to determine the through-the-thickness compressive (TTTC) material properties. A total of 206 property tests were performed on four different graphite/epoxy material systems. The results confirmed that TTTC material properties vary with fiber orientation, laminate thickness, fiber volume fraction, and even laminate surface finish. Hence, the 'rule of mixtures' provides a poor estimate of the TTTC modulus in that it fails to account for any of these variables.</p> <p>Finally, acoustic emission nondestructive testing, along with a modified approach to MSFC-STD-486B, Torque Limits for Standard Threaded Fastener, were used to determine the torque limit of a fastener in a single lap joint. The laminate configuration examined in these tests was manufactured in accordance with the MIL-HDBK-17 design code. The results demonstrated the inability of the fasteners employed to damage the one composite system investigated: fastener thread failure occurred first. Further study is necessary to confirm or refute these results for other composite systems and joint configurations.</p>","abstract_has_math":false,"creators":["Kostreva, Kristian M."],"institution":null,"degree_name":"Master of Science in Aerospace Engineering","degree_level":"Thesis - Open Access","degree_discipline":"Aerospace Engineering","degree_department":null,"school":null,"contributors":["Yi Zhao","Eric v. K. Hill","Frank J. Radosta"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2002,"date_issued":"2002-12-01T08:00:00Z","date_published":"2002-12-01T08:00:00Z","updated_at":"2026-07-27T19:25:23Z","subjects":["torque","mechanical fastener","graphite/epoxy","acoustic emission","nondestructive testing","Aerospace Engineering","Structures and Materials"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://commons.erau.edu/db-theses/105","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Yi Zhao","Eric v. K. Hill","Frank J. Radosta"]},{"key":"dc:creator","label":"Author","values":["Kostreva, Kristian M."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - Open Access"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Aerospace Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["torque","mechanical fastener","graphite/epoxy","acoustic emission","nondestructive testing","Aerospace Engineering","Structures and Materials"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://commons.erau.edu/db-theses/105"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Presently there is a lack of confidence amongst engineers when specifying the preload of a mechanical fastener in a composite joint due to a lack of a fundamental knowledge base regarding the behavior of composites under fastener compressive load. As such, a novel experimental procedure was developed herein to determine the through-the-thickness compressive (TTTC) material properties. A total of 206 property tests were performed on four different graphite/epoxy material systems. The results confirmed that TTTC material properties vary with fiber orientation, laminate thickness, fiber volume fraction, and even laminate surface finish. Hence, the 'rule of mixtures' provides a poor estimate of the TTTC modulus in that it fails to account for any of these variables.
Finally, acoustic emission nondestructive testing, along with a modified approach to MSFC-STD-486B, Torque Limits for Standard Threaded Fastener, were used to determine the torque limit of a fastener in a single lap joint. The laminate configuration examined in these tests was manufactured in accordance with the MIL-HDBK-17 design code. The results demonstrated the inability of the fasteners employed to damage the one composite system investigated: fastener thread failure occurred first. Further study is necessary to confirm or refute these results for other composite systems and joint configurations.
"]},{"key":"dc:title","label":"Title","values":["Torque Limit of a Mechanical Fastener in a Graphite/Epoxy Joint"]}]}],"canonical_facts":{"dc:contributor":["Yi Zhao","Eric v. K. Hill","Frank J. Radosta"],"dc:creator":["Kostreva, Kristian M."],"dc:description.abstract":["Presently there is a lack of confidence amongst engineers when specifying the preload of a mechanical fastener in a composite joint due to a lack of a fundamental knowledge base regarding the behavior of composites under fastener compressive load. As such, a novel experimental procedure was developed herein to determine the through-the-thickness compressive (TTTC) material properties. A total of 206 property tests were performed on four different graphite/epoxy material systems. The results confirmed that TTTC material properties vary with fiber orientation, laminate thickness, fiber volume fraction, and even laminate surface finish. Hence, the 'rule of mixtures' provides a poor estimate of the TTTC modulus in that it fails to account for any of these variables.
Finally, acoustic emission nondestructive testing, along with a modified approach to MSFC-STD-486B, Torque Limits for Standard Threaded Fastener, were used to determine the torque limit of a fastener in a single lap joint. The laminate configuration examined in these tests was manufactured in accordance with the MIL-HDBK-17 design code. The results demonstrated the inability of the fasteners employed to damage the one composite system investigated: fastener thread failure occurred first. Further study is necessary to confirm or refute these results for other composite systems and joint configurations.
"],"dc:identifier":["https://commons.erau.edu/db-theses/105"],"dc:subject":["torque","mechanical fastener","graphite/epoxy","acoustic emission","nondestructive testing","Aerospace Engineering","Structures and Materials"],"dc:title":["Torque Limit of a Mechanical Fastener in a Graphite/Epoxy Joint"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["Thesis - Open Access"],"thesis:degree_name":["Master of Science in Aerospace Engineering"]},"updated_at":"2026-07-27T19:25:23Z"}