Research On Vehicle Ride Comfort Of The McPherson Suspension System

With the rapid development of automobile industry technology,people are increasingly demanding more comfort of automobiles.The suspension system is an important mechanism that affects the ride comfort,handling stability and safety of automobiles.Therefore,the research on it has become a key research issue in recent years.In order to study the smoothness of the car better,the article focus on a certain type of car,using multi-body dynamics analysis software ADAMS to study the smoothness of the suspension and simulation,and on the front of the car McPherson suspension.The main content is as follows:1)By assembled the model of a McPherson suspension of a car and then used ANSYS Workbench to analyze the behavior of the suspension under the three typical conditions of bumpy road surface,braking and turning.The natural frequency is obtained through the modal analysis of the suspension.Compare with the internal and external incentives of vehicles under the different operating conditions.2)The damping spring is an important role supporting the load and relieving the vibration in the suspension system which has a greater influence on the ride comfort of the vehicle.So in this paper,considered the bending moment and torque of the coil spring cross-section,the formula for the calculation of the shear stress of the spring is derived.The strength of the spring is compared by the stress analysis of cylindrical coil spring and truncated cone spring.Then modal analysis of the two spring models,it can be known that the natural frequency of the truncated cone spring is slightly lower than the natural frequency of the cylindrical spring.The mass of the truncated cone spring studied in this study is 10.3%lower than that of the cylindrical coil spring.Therefore,the stiffness of the truncated cone spring is lower than that of the cylindrical spring.Then the cylindrical spring and the truncated cone spring are respectively used as the damping springs of the suspension to perform the harmonic response analysis of the suspension.Get that the suspension of conical spring is more stable.3)The influence of the stiffness and damping coefficient of the suspension on the ride comfort of the automobile is studied.Through the analysis,recommended the suitable range of suspension stiffness and the damping ratio of the suspension to further improve the vehicle ride comfort.Then,through the establishment of a four-degree-of-freedom dynamic model of the suspension,the response analysis of vertical and pitching vibration is carried out by using Simulink.Based on the analysis results,it is known that the rear wheel movement has a great influence on the vibration of the rear axle.The front wheel movement has a great influence on the body pitch vibration and the front axle vibration.4)The impact of automotive smoothness is analyzed by ADAMS/CAR through the effect of road surface roughness(levels B and C)on vehicle ride comfort at 80km/h.And,the effect of speed(60km/h and 80km/h)on the smoothness of the car was analyzed under the road of class B.Then,the different damping spring stiffness on vehicle ride comfort was compared and analyzed by the conditions of the same road surface and the same speed.Finally,the root mean square value of the total acceleration after the movement of the car's center of mass is compared and analyzed.Based on the analysis,it can be seen that the forward movement of the center of mass helps to improve the smoothness of the car,and the upward movement has the tendency to improve the ride comfort of the car,and both the backward movement and the downward movement cause the car to be smooth.This topic is to study the problem of damage to goods caused by the mprovement of people's comfort in riding a car and logistics transportation.The results of the study provide reference for improving the smoothness of cars.