{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/42109"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/42109","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Characterizing a Racing Damper's Frequency Dependent Behavior with an Emphasis on High Frequency Inputs","abstract":"As a racecar negotiates a track, it is subjected to many inputs at both high and low frequencies. These inputs come from the track surface, the motion of the body, and from aerodynamic disturbances. The damper's ability to control these inputs leads to improved grip at the tires, which increases overall handling of the vehicle. Since dampers have always been assumed to be primarily velocity dependent, little work has gone into exploring damper's frequency dependent nature. Therefore, this study evaluates the effect input frequency has on the damper's output force. Utilizing experimental testing, with a state of the art damper dynamometer, and computer simulation with a parametric damper model developed for this study, several inputs and key parameters are tested, and the damper's frequency dependent nature starts to emerge. Constant peak velocity sinusoidal and sinusoidal sweep inputs are used for the experimental testing. The results show that as the input frequency is increased, the damper's output force lissajou transitions from the characteristic shape of a damper's lissajou to a shape characteristic of a spring's lissajou. This change in the lissajou is linked to hysteretic effects, which includes the gas spring effect. Damper parameters that are suspected to contribute to the hysteretic effects are explored with computer simulation and additional experimental testing. The results from this show that fluid preparation, fluid type, initial gas pressure, and friction have a predictable effect on the damper's output force.","abstract_html":"As a racecar negotiates a track, it is subjected to many inputs at both high and low frequencies. These inputs come from the track surface, the motion of the body, and from aerodynamic disturbances. The damper's ability to control these inputs leads to improved grip at the tires, which increases overall handling of the vehicle. Since dampers have always been assumed to be primarily velocity dependent, little work has gone into exploring damper's frequency dependent nature. Therefore, this study evaluates the effect input frequency has on the damper's output force. Utilizing experimental testing, with a state of the art damper dynamometer, and computer simulation with a parametric damper model developed for this study, several inputs and key parameters are tested, and the damper's frequency dependent nature starts to emerge. Constant peak velocity sinusoidal and sinusoidal sweep inputs are used for the experimental testing. The results show that as the input frequency is increased, the damper's output force lissajou transitions from the characteristic shape of a damper's lissajou to a shape characteristic of a spring's lissajou. This change in the lissajou is linked to hysteretic effects, which includes the gas spring effect. Damper parameters that are suspected to contribute to the hysteretic effects are explored with computer simulation and additional experimental testing. The results from this show that fluid preparation, fluid type, initial gas pressure, and friction have a predictable effect on the damper's output force.","abstract_has_math":false,"creators":["Emmons, Shawn Glendon"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Mechanical Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Ahmadian, Mehdi"],"committee_members":["Southward, Steve C.","Ferris, John B."],"year":2007,"date_issued":"2007-04-05","date_published":"2007-04-05","updated_at":"2026-07-22T22:18:41Z","subjects":["race damper","shock absorbers","high frequency characterization"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04162007-093704"],"render_values":[{"text":"etd-04162007-093704","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/42109","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Ahmadian, Mehdi"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Southward, Steve C.","Ferris, John B."]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Emmons, Shawn Glendon"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:33:53Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:33:53Z","2007-04-19"]},{"key":"dc:date.issued","label":"Date","values":["2007-04-05"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"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":["race damper","shock absorbers","high frequency characterization"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-04162007-093704"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/42109"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["As a racecar negotiates a track, it is subjected to many inputs at both high and low frequencies. These inputs come from the track surface, the motion of the body, and from aerodynamic disturbances. The damper's ability to control these inputs leads to improved grip at the tires, which increases overall handling of the vehicle. Since dampers have always been assumed to be primarily velocity dependent, little work has gone into exploring damper's frequency dependent nature. Therefore, this study evaluates the effect input frequency has on the damper's output force. Utilizing experimental testing, with a state of the art damper dynamometer, and computer simulation with a parametric damper model developed for this study, several inputs and key parameters are tested, and the damper's frequency dependent nature starts to emerge. Constant peak velocity sinusoidal and sinusoidal sweep inputs are used for the experimental testing. The results show that as the input frequency is increased, the damper's output force lissajou transitions from the characteristic shape of a damper's lissajou to a shape characteristic of a spring's lissajou. This change in the lissajou is linked to hysteretic effects, which includes the gas spring effect. Damper parameters that are suspected to contribute to the hysteretic effects are explored with computer simulation and additional experimental testing. The results from this show that fluid preparation, fluid type, initial gas pressure, and friction have a predictable effect on the damper's output force."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Characterizing a Racing Damper's Frequency Dependent Behavior with an Emphasis on High Frequency Inputs"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Ahmadian, Mehdi"],"dc:contributor.committeemember":["Southward, Steve C.","Ferris, John B."],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Emmons, Shawn Glendon"],"dc:date.accessioned":["2014-03-14T21:33:53Z"],"dc:date.available":["2014-03-14T21:33:53Z","2007-04-19"],"dc:date.issued":["2007-04-05"],"dc:description.abstract":["As a racecar negotiates a track, it is subjected to many inputs at both high and low frequencies. These inputs come from the track surface, the motion of the body, and from aerodynamic disturbances. The damper's ability to control these inputs leads to improved grip at the tires, which increases overall handling of the vehicle. Since dampers have always been assumed to be primarily velocity dependent, little work has gone into exploring damper's frequency dependent nature. Therefore, this study evaluates the effect input frequency has on the damper's output force. Utilizing experimental testing, with a state of the art damper dynamometer, and computer simulation with a parametric damper model developed for this study, several inputs and key parameters are tested, and the damper's frequency dependent nature starts to emerge. Constant peak velocity sinusoidal and sinusoidal sweep inputs are used for the experimental testing. The results show that as the input frequency is increased, the damper's output force lissajou transitions from the characteristic shape of a damper's lissajou to a shape characteristic of a spring's lissajou. This change in the lissajou is linked to hysteretic effects, which includes the gas spring effect. Damper parameters that are suspected to contribute to the hysteretic effects are explored with computer simulation and additional experimental testing. The results from this show that fluid preparation, fluid type, initial gas pressure, and friction have a predictable effect on the damper's output force."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-04162007-093704"],"dc:identifier.uri":["http://hdl.handle.net/10919/42109"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["race damper","shock absorbers","high frequency characterization"],"dc:title":["Characterizing a Racing Damper's Frequency Dependent Behavior with an Emphasis on High Frequency Inputs"],"dc:type":["Thesis"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:41Z"}