Study On The Comfort Of High-speed Train Drivers In A Windy Environment

High-speed railways must not only ensure the safe operation of trains,but also must improve the comfort of passengers and staff,especially drivers.Due to the vast territory of China,many high-speed rail lines pass through the windy area,and coupled with changes in meteorological conditions,high-speed trains often operate under strong wind conditions.Compared with the windless condition,the surface aerodynamic loads and vehicle dynamics of the train under the action of strong winds are significantly changed.The change of vehicle vibration characteristics directly affects the riding comfort of the people.For the high-speed train driver,not only is it easy to fatigue,but also the front position of the train is the position where the vibration response of the entire train changes most obviously,and the comfort of the driving involves safety risks.Therefore,the research on driver's comfort has important practical significance.At the same time,it is also of high scientific value to analyze the ride comfort of people in a windy environment combined with human body dynamics.According to the logic sequence of "train aerodynamic characteristics-vehicle dynamic response-human biomechanical properties-human body comfort evaluation",this paper studies the comfort of high-speed train drivers under strong wind conditions.Without loss of generality,taking the domestic CRH3 high-speed train as the research object,firstly analyzed the changes in the aerodynamic loads of the train under different wind speeds and different vehicle speed conditions,and then considered the wheel-rail adhesion and track line irregularity,and established the track-wheelset-bogie-vehicle-seat dynamics model,then load the aerodynamic loads on the train,calculated the vehicle dynamics and train vibration response under different operating conditions,and obtained the vibration characteristics of the carriage and the seat.Subsequently,the"seat-human" vibration transmission model was established and the vibration response of the seat was introduced into the human body dynamics model.The vibration responses of the driver's body in various operating conditions were calculated.On this basis,the influencing laws of changes in wind speed and speed on the human body's vibration response are summarized,and the main factors affecting comfort are analyzed from the perspective of the human body and the mechanism of' action,and a comprehensive evaluation of the ride comfort of the driver is performed.Finally,the method of human comfort evaluation was discussed.The limitation of the existing evaluation methods was pointed out,and the optimization suggestions were put forward.The results show that when the wind speed is constant,the acceleration of the vehicle body and the train running speed become approximately linearly increasing,and the vertical acceleration is always greater than the lateral acceleration under the same working conditions;The body vibration acceleration response is not sensitive to the cross wind effect.The cross wind effect mainly changes the dynamic characteristics of the high speed train by changing the dynamic parameters other than the body acceleration.At the same time.the vibration acceleration of the driver's body gradually increases with the increase of the vehicle speed,and it is greater than the vibration acceleration of the vehicle body,that is,the vibration acceleration of the vehicle body has an increasing effect after being transmitted to the human body;under the same working conditions,the vibration acceleration of the human head is greater than that of the trunk.Among the two main factors of comfort evaluation,the change of vehicle speed has a greater influence on the RMS value of total weighted acceleration of whole body vibration,and its value increases with the increase of the vehicle speed,and therefore the comfort is reduced,and the change of wind speed has little effect on it.The change of the wind speed has a great influence on the lateral displacement value of the human body vibration.so that the frequency of the lateral vibration of the human body is reduced,and it is closer to the first resonance region of the human body,this may adversely affect the comfort.