In this paper,I established a single crawler model with a dynamic contact force considered.I modeled each crawler track using dynamic contact model.By modeling each crawler track,I hope to be able to analyze trafficab...In this paper,I established a single crawler model with a dynamic contact force considered.I modeled each crawler track using dynamic contact model.By modeling each crawler track,I hope to be able to analyze trafficability of a crawler type vehicle in various road surfaces.First,I think that I established a single crawler model.I modeled a single crawler using Hunt-Crossley model and Coulomb model that handle a nonlinear contact force model.And also,I built a prototype single crawler for comparing the experimental examination with the simulation examination.In advance,the running over limit of the prototype single crawler was analyzed geometrically,and I bore out that it could run over to 163 mm.Therefore,I conducted the experiment examination with step height of 160 mm and 165 mm and obtained trajectory data that were allowed to run over and were not allowed to run over.From the result of both the experimental examination and the simulation examination,I bore out the validity of our single crawler model.I described about our single crawler model,the simulation examination and the experimental examination in this paper.展开更多
To improve the driving comfort of combine harvesters,driver seat low-frequency vibration and related driver ride-comfort problems were investigated on a Chinese CFFL-850 crawler-type full-feed combine harvester based ...To improve the driving comfort of combine harvesters,driver seat low-frequency vibration and related driver ride-comfort problems were investigated on a Chinese CFFL-850 crawler-type full-feed combine harvester based on ISO2631.Driver vibration and driving seat transmission characteristics were measured under the following conditions:no-load idling,driving on the road,driving in the field,and simulated harvesting.The root mean square values composite vibration under four conditions were 3.63 m/s^(2),2.35 m/s^(2),3.34 m/s^(2),and 2.67 m/s^(2),respectively.For the same condition,the maximum root mean square scores of vibration component on driver whole-body occurred in the seat support surface(test point 1)and vertical direction(Z direction),which were 3.56 m/s^(2),2.05 m/s^(2),3.15 m/s^(2),and 2.43 m/s^(2),respectively.The test point 2 to test point 1 vertical-transfer function curve trends were nearly identical.Nearly all of the transfer coefficients were greater than 1 in the range of 1-50 Hz,therefore,the seat vibration attenuation performance was poor.Based on the analysis results,the driver seat structure was altered and a verification test was performed.The test results indicated that after an X-damping mechanism was installed,vibration acceleration,on the surface of the seat support under the road-driving conditions,decreased from 2.35 m/s^(2) to 1.68 m/s^(2).Under the simulated harvesting condition,the vibration acceleration decreased from 2.56 m/s^(2) to 1.46 m/s^(2).Nearly all of the seat vertical transfer coefficients were less than 1 within the frequency range of 1-80 Hz,therefore the dynamic comfort of the seat was ameliorated after structural improvement.展开更多
文摘In this paper,I established a single crawler model with a dynamic contact force considered.I modeled each crawler track using dynamic contact model.By modeling each crawler track,I hope to be able to analyze trafficability of a crawler type vehicle in various road surfaces.First,I think that I established a single crawler model.I modeled a single crawler using Hunt-Crossley model and Coulomb model that handle a nonlinear contact force model.And also,I built a prototype single crawler for comparing the experimental examination with the simulation examination.In advance,the running over limit of the prototype single crawler was analyzed geometrically,and I bore out that it could run over to 163 mm.Therefore,I conducted the experiment examination with step height of 160 mm and 165 mm and obtained trajectory data that were allowed to run over and were not allowed to run over.From the result of both the experimental examination and the simulation examination,I bore out the validity of our single crawler model.I described about our single crawler model,the simulation examination and the experimental examination in this paper.
基金This research was supported by the National Natural Science Foundation of China(51475217)the Fok Ying-Tong Education Foundation of China(Grant No.141051)+1 种基金Six Talent Peaks Project in Jiangsu Province(NY-024)a project funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘To improve the driving comfort of combine harvesters,driver seat low-frequency vibration and related driver ride-comfort problems were investigated on a Chinese CFFL-850 crawler-type full-feed combine harvester based on ISO2631.Driver vibration and driving seat transmission characteristics were measured under the following conditions:no-load idling,driving on the road,driving in the field,and simulated harvesting.The root mean square values composite vibration under four conditions were 3.63 m/s^(2),2.35 m/s^(2),3.34 m/s^(2),and 2.67 m/s^(2),respectively.For the same condition,the maximum root mean square scores of vibration component on driver whole-body occurred in the seat support surface(test point 1)and vertical direction(Z direction),which were 3.56 m/s^(2),2.05 m/s^(2),3.15 m/s^(2),and 2.43 m/s^(2),respectively.The test point 2 to test point 1 vertical-transfer function curve trends were nearly identical.Nearly all of the transfer coefficients were greater than 1 in the range of 1-50 Hz,therefore,the seat vibration attenuation performance was poor.Based on the analysis results,the driver seat structure was altered and a verification test was performed.The test results indicated that after an X-damping mechanism was installed,vibration acceleration,on the surface of the seat support under the road-driving conditions,decreased from 2.35 m/s^(2) to 1.68 m/s^(2).Under the simulated harvesting condition,the vibration acceleration decreased from 2.56 m/s^(2) to 1.46 m/s^(2).Nearly all of the seat vertical transfer coefficients were less than 1 within the frequency range of 1-80 Hz,therefore the dynamic comfort of the seat was ameliorated after structural improvement.
