An improved modeling methodology,considering heat change,friction and inertia of components,is proposed.The relay valve used in tractor-semitrailers is taken as an example to develop the mathematical model.The resulti...An improved modeling methodology,considering heat change,friction and inertia of components,is proposed.The relay valve used in tractor-semitrailers is taken as an example to develop the mathematical model.The resulting simulation for time lag,developed based on this model,is validated by experiment.The results show that the time lag of this relay valve is 0.12.s while the experimental value is 0.131.s,which means that the response time can be simulated accurately.The comparison between simulation and experiment also shows that the main factor affecting the response time of the relay valve is the movement time of the internal piston and valve head.These results indicate that the model of the relay valve is effective,and the modeling methodology is verified.This research could provide reference for related studies.展开更多
A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road ...A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road roughness is completed by means of computer simulationand power spectral density (PSD) approach in all of road conditions and loading cases. The resultsshow that the severest situation of response of the system occurs when the road in rough conditionand vehicle unladen. The most sensitive frequency to human body parts is around 0.9 Hz, and modeltypes of a human body seem to be not significant to the response of a heavy tractor-semitrailersystem, including to the response of the driver himself.展开更多
文摘An improved modeling methodology,considering heat change,friction and inertia of components,is proposed.The relay valve used in tractor-semitrailers is taken as an example to develop the mathematical model.The resulting simulation for time lag,developed based on this model,is validated by experiment.The results show that the time lag of this relay valve is 0.12.s while the experimental value is 0.131.s,which means that the response time can be simulated accurately.The comparison between simulation and experiment also shows that the main factor affecting the response time of the relay valve is the movement time of the internal piston and valve head.These results indicate that the model of the relay valve is effective,and the modeling methodology is verified.This research could provide reference for related studies.
文摘A linear mass-spring system model of a tractor-semitrailer together withdriver body parts and sprung seat is presented. Natural frequencies of the system are calculated andresponse of components in the system to road roughness is completed by means of computer simulationand power spectral density (PSD) approach in all of road conditions and loading cases. The resultsshow that the severest situation of response of the system occurs when the road in rough conditionand vehicle unladen. The most sensitive frequency to human body parts is around 0.9 Hz, and modeltypes of a human body seem to be not significant to the response of a heavy tractor-semitrailersystem, including to the response of the driver himself.
