Study On The Methods Of Wheel Road Load Signal Measurement And Processing

This paper focuses on studying the measurement and processing methods of the road load signals of passenger car wheel.The road load signals of the front wheels of a passenger car was made on Xiangfan proving ground, which include the strains on the front suspension of the car sensitive to vertical, lateral, longitudinal and braking force. The static calibration test stand of suspension-wheel were designed and manufactured, with which the static calibration test was made to determine the relationship matrix between the suspension strains and vertical, lateral and braking force applied. And the matrix was used to transform the suspension strains measured into the vertical, lateral and braking force signals. The vertical and lateral forces were used to form the bending moment on the wheel according to the wheel dynamic cornering fatigue test requirement.I-DEAS software was used to do static and dynamic wheel finite element analysis, in which the loading and restraint conditions were applied. The relationship between the bending moment applied and the strain of the critical point of wheel was determined according to the results of the static wheel finite element analysis. The relationship between the amplitude of dynamic wheel stress and static stress at different excitation frequency was determined with dynamic wheel finite element analysis. The wheel bending moment signals were transformed into the strain signals(road running strains) of the wheel critical point by use of the results of finite element analysis mentioned above.Fatigue analysis software FASP was used to process the strain signals of the wheel critical point mentioned above and determine the corresponding fatigue damage(road running fatigue damage) and life of the left and right front wheels. The method of fatigue life prediction applied is local stress-strain method. The dynamic wheel finite element analysis and local stress-strain method were combined to calculate the wheel fatigue life in the wheel dynamic cornering fatigue test and the predicted life was quite close to the test life with a relative error of 6.7%, indicating that the method is reasonable.The calculated road running fatigue damage and the wheel dynamic cornering fatigue test results were used to predict the relationship between the number of the bending fatigue cycles on the test stand and the mileage on Xiangfan proving ground.