{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/141137"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/141137","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Analysis of a Nonlinear vibration absorber for vibration control in a hand-held impact machine","abstract":"Hand-held impact machines (HIMs), such as jackhammers and chipping hammers, operate through the repetitive impacts of a percussive mechanism. Due to their widespread use, it is essential that these tools are designed for safe daily operation. This need is underscored by the fact that approximately 20% of operators risk developing vibration-related hand injuries, which can be career-ending. As a step toward improving the safety of these tools, this dissertation focuses on modeling their dynamic behavior to evaluate the effectiveness of vibration control strategies. The novelty of this work lies in the use of nonlinear mass– spring–damper models to describe tool dynamics, coupled with lumped-mass models of the hand–arm system. Traditionally, linear models have been employed for such evaluations; by contrast, this study introduces nonlinear modeling to capture the more realistic dynamics of HIMs. Furthermore, the role of a cubic nonlinear absorber in attenuating vibrations transmitted to the hand is systematically investigated through this framework. Key findings include the observation of nonlinear phenomena such as unstable periodic solutions, quasi- periodicity, chaos, and grazing. Frequency response analyses demonstrate the superiority of the cubic absorber over its linear counterpart, with notable improvements in performance when combined with an inerter. Parametric studies further reveal how the absorber can be tuned to enhance vibration attenuation across different nonlinear HIM models.","abstract_html":"Hand-held impact machines (HIMs), such as jackhammers and chipping hammers, operate through the repetitive impacts of a percussive mechanism. Due to their widespread use, it is essential that these tools are designed for safe daily operation. This need is underscored by the fact that approximately 20% of operators risk developing vibration-related hand injuries, which can be career-ending. As a step toward improving the safety of these tools, this dissertation focuses on modeling their dynamic behavior to evaluate the effectiveness of vibration control strategies. The novelty of this work lies in the use of nonlinear mass– spring–damper models to describe tool dynamics, coupled with lumped-mass models of the hand–arm system. Traditionally, linear models have been employed for such evaluations; by contrast, this study introduces nonlinear modeling to capture the more realistic dynamics of HIMs. Furthermore, the role of a cubic nonlinear absorber in attenuating vibrations transmitted to the hand is systematically investigated through this framework. Key findings include the observation of nonlinear phenomena such as unstable periodic solutions, quasi- periodicity, chaos, and grazing. Frequency response analyses demonstrate the superiority of the cubic absorber over its linear counterpart, with notable improvements in performance when combined with an inerter. Parametric studies further reveal how the absorber can be tuned to enhance vibration attenuation across different nonlinear HIM models.","abstract_has_math":false,"creators":["Alabi, Oreoluwa Adekolade"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Engineering Mechanics","degree_department":"Engineering Science and Mechanics","school":null,"contributors":[],"advisors":[],"committee_chairs":["Barry, Oumar"],"committee_members":["Abaid, Nicole Teresa","Behkam, Bahareh","Batra, Romesh C."],"year":2026,"date_issued":"2026-02-03","date_published":"2026-02-03","updated_at":"2026-07-22T22:20:34Z","subjects":["Nonlinear Dynamics"],"languages":["en"],"rights":["Creative Commons Attribution 4.0 International"],"rights_urls":["http://creativecommons.org/licenses/by/4.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:44848"],"render_values":[{"text":"vt_gsexam:44848","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/141137","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Barry, Oumar"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Abaid, Nicole Teresa","Behkam, Bahareh","Batra, Romesh C."]},{"key":"dc:contributor.department","label":"Department","values":["Engineering Science and Mechanics"]},{"key":"dc:creator","label":"Author","values":["Alabi, Oreoluwa Adekolade"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-02-04T09:01:07Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-02-04T09:01:07Z"]},{"key":"dc:date.issued","label":"Date","values":["2026-02-03"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Engineering Mechanics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Nonlinear Dynamics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Creative Commons Attribution 4.0 International"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://creativecommons.org/licenses/by/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:44848"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/141137"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Hand-held impact machines (HIMs), such as jackhammers and chipping hammers, operate through the repetitive impacts of a percussive mechanism. Due to their widespread use, it is essential that these tools are designed for safe daily operation. This need is underscored by the fact that approximately 20% of operators risk developing vibration-related hand injuries, which can be career-ending. As a step toward improving the safety of these tools, this dissertation focuses on modeling their dynamic behavior to evaluate the effectiveness of vibration control strategies. The novelty of this work lies in the use of nonlinear mass– spring–damper models to describe tool dynamics, coupled with lumped-mass models of the hand–arm system. Traditionally, linear models have been employed for such evaluations; by contrast, this study introduces nonlinear modeling to capture the more realistic dynamics of HIMs. Furthermore, the role of a cubic nonlinear absorber in attenuating vibrations transmitted to the hand is systematically investigated through this framework. Key findings include the observation of nonlinear phenomena such as unstable periodic solutions, quasi- periodicity, chaos, and grazing. Frequency response analyses demonstrate the superiority of the cubic absorber over its linear counterpart, with notable improvements in performance when combined with an inerter. Parametric studies further reveal how the absorber can be tuned to enhance vibration attenuation across different nonlinear HIM models."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Hand-held impact machines like jackhammers and chipping hammers are widely used in construction, mining and manufacturing but can expose workers to harmful vibrations. Long- term use can cause hand–arm vibration syndrome (HAVS), a condition affecting nearly 20% of operators and leading to pain, loss of grip, and even permanent disability. This dissertation develops mathematical models to better understand how these vibrations occur and how they can be reduced. Unlike traditional studies that rely on simplified linear models, this work uses nonlinear models that more accurately capture the complex dynamics of impact tools and their interaction with the hand–arm system. A special focus is placed on testing cubic nonlinear absorbers — devices designed to counteract vibrations. Results show that these absorbers can outperform standard designs, especially when combined with an inerter element, and offer pathways for safer tool design. Ultimately, this work aims to guide engineering solutions that reduce injuries and extend worker careers."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Analysis of a Nonlinear vibration absorber for vibration control in a hand-held impact machine"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Barry, Oumar"],"dc:contributor.committeemember":["Abaid, Nicole Teresa","Behkam, Bahareh","Batra, Romesh C."],"dc:contributor.department":["Engineering Science and Mechanics"],"dc:creator":["Alabi, Oreoluwa Adekolade"],"dc:date.accessioned":["2026-02-04T09:01:07Z"],"dc:date.available":["2026-02-04T09:01:07Z"],"dc:date.issued":["2026-02-03"],"dc:description.abstract":["Hand-held impact machines (HIMs), such as jackhammers and chipping hammers, operate through the repetitive impacts of a percussive mechanism. Due to their widespread use, it is essential that these tools are designed for safe daily operation. This need is underscored by the fact that approximately 20% of operators risk developing vibration-related hand injuries, which can be career-ending. As a step toward improving the safety of these tools, this dissertation focuses on modeling their dynamic behavior to evaluate the effectiveness of vibration control strategies. The novelty of this work lies in the use of nonlinear mass– spring–damper models to describe tool dynamics, coupled with lumped-mass models of the hand–arm system. Traditionally, linear models have been employed for such evaluations; by contrast, this study introduces nonlinear modeling to capture the more realistic dynamics of HIMs. Furthermore, the role of a cubic nonlinear absorber in attenuating vibrations transmitted to the hand is systematically investigated through this framework. Key findings include the observation of nonlinear phenomena such as unstable periodic solutions, quasi- periodicity, chaos, and grazing. Frequency response analyses demonstrate the superiority of the cubic absorber over its linear counterpart, with notable improvements in performance when combined with an inerter. Parametric studies further reveal how the absorber can be tuned to enhance vibration attenuation across different nonlinear HIM models."],"dc:description.abstractgeneral":["Hand-held impact machines like jackhammers and chipping hammers are widely used in construction, mining and manufacturing but can expose workers to harmful vibrations. Long- term use can cause hand–arm vibration syndrome (HAVS), a condition affecting nearly 20% of operators and leading to pain, loss of grip, and even permanent disability. This dissertation develops mathematical models to better understand how these vibrations occur and how they can be reduced. Unlike traditional studies that rely on simplified linear models, this work uses nonlinear models that more accurately capture the complex dynamics of impact tools and their interaction with the hand–arm system. A special focus is placed on testing cubic nonlinear absorbers — devices designed to counteract vibrations. Results show that these absorbers can outperform standard designs, especially when combined with an inerter element, and offer pathways for safer tool design. Ultimately, this work aims to guide engineering solutions that reduce injuries and extend worker careers."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:44848"],"dc:identifier.uri":["https://hdl.handle.net/10919/141137"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["Creative Commons Attribution 4.0 International"],"dc:rights.uri":["http://creativecommons.org/licenses/by/4.0/"],"dc:subject":["Nonlinear Dynamics"],"dc:title":["Analysis of a Nonlinear vibration absorber for vibration control in a hand-held impact machine"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Engineering Mechanics"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:34Z"}