Research On Axle Load And Life Of Hexie Heavy-duty Six-axle Locomotive

The locomotive axle,as a crucial bearing component in the bogie,is critical to the vehicle’s safe operation.This dissertation takes a axle of Hexie six-axle locomotive as the research object.Based on the measured data of the Baoqin line under multiple working conditions,the load spectrum under different working conditions and the stress spectrum under comprehensive working conditions are compiled to analyze the dynamic load of the axle and evaluate the fatigue.The strength of each axle of the locomotive is studied by the joint simulation of finite element and dynamic software,and the load characteristics and dynamic stress are simulated.The main research contents and results are as follows:(1)According to the EN13103-2017 standard,the finite element simulation method is used to determine the key positions of the axles,the instrumented wheelset is developed,the vertical,lateral and longitudinal loads are arranged to identify the bridge,and the finite element method and theoretical calculation are used for calibration to obtain the transfer coefficient to the load in XYZ directions.(2)Complete the test on the Baoqin line,and carry out data processing and analysis;according to the line conditions and speed,carry out the analysis of the axle load characteristics.Using the rainflow counting method combined with the MATLAB statistical analysis method,the one-dimensional and two-dimensional load spectra under various working conditions were compiled for the three-directional load time domain signal.(3)According to the measured dynamic stress of different key sections of the axle,the rain flow method was used to compile the stress spectrum of the axle under the whole operating condition.According to Miner’s linear cumulative damage theory,the equivalent stress of the key section of the axle is calculated.According to Miner’s linear cumulative damage theory,the equivalent stress of the key sections of the axle is calculated,and the life of each section after parameter correction is calculated..Comparing the effects of one-way stress and two-way stress on the fatigue life of the axle,compared with the bending stress,the damage caused by the torque of the axle is smaller,and the resultant stress can be calculated in the form of a safety factor.(4)The vehicle dynamics model of the six-axle locomotive is established,and the influence of the curve radius,speed level,wheel polygon,and starting and braking conditions on the load characteristics of each axle is analyzed: as the curve radius decreases,the vertical load of the axle is eccentric.Gradually increased,the maximum reduction rate of wheel load reached 0.38;the eccentric load of the wheel and axle became worse with the increase of the running speed;The amplitude of the wheel-axle load was sensitive to the 15-19 order polygon response;The displacement of the axle load caused the transfer of the axle load.The load response of the axle near the center of the car body was weak,and the load of the axle far away from the center of the car body increased and decreased significantly.The axle stress is simulated based on the stress recovery method,and the simulation results are in good agreement with the actual measurement to a certain extent.The stress spectrum of the simulated stress is basically consistent with the actual measurement,which can reflect the load characteristics.