Test And Simulation Of Friction Noise Of Brake Pad-Reed System

The NVH(Noise,Vibration and Harshness)performance of vehicles has always been an indicator that car manufacturers and consumers are more concerned about,and the vibration and noise of vehicles have been paid more attention to.The noise generated by the automobile braking system will not only cause interference to the driver and bring a bad experience to the comfort of the passengers,but also have a certain impact on the urban environment and pedestrians around.At present,for the research of vehicle brake system noise,several methods of experimental analysis,theoretical analysis and finite element analysis have been formed.Researchers often combine several methods to analyze the generation mechanism of brake system noise and its influencing factors.At this stage,brake discs and friction squeals due to friction usually have some characteristics such as high frequency and large energy,which are the focus and research focus of friction noise.However,the abnormal noise generated between the friction plate and the circlip is rarely paid attention to by researchers,and some related research and literature reports are also rare.In the process of braking and releasing the brake,the friction plates will come into frictional contact with the circlips at both ends.When a certain energy value is reached,noise will be radiated outwards,especially when the vehicle is on an uneven road surface.The mutual contact relationship between the springs may change,which will make the abnormal sound more obvious.In this paper,with reference to the related friction noise research methods,a vibration and noise test bench was built,and a finite element model of friction plates and circlips was established.With the help of the test methods and finite element simulation methods,the friction coefficient,sliding speed and other factors were investigated for friction.The mechanism of the noise of the plate-retainer system.Furthermore,a dynamic model of the system was established to investigate the influence of sliding speed,static friction coefficient and viscous friction coefficient on the dynamic characteristics of the system.The main contents of this article are summarized as follows:1.Combining the research status of friction noise at home and abroad,the research background of friction vibration and noise between the friction plate and the circlip is explained,the significance of the research is explained,and the structure and working principle of the system are briefly explained.The friction model was elaborated and analyzed,which paved the way for the establishment of dynamic model.2.A simple vibration and noise test bench was built,and the vibration signal and noise signal generated by the friction plate-retainer friction were obtained through the Siemens LMS Test.Lab data acquisition system,and the free-mode simulation analysis was performed on the retainer,Comparative test analysis results.3.With reference to the actual geometric model,through reasonable simplification,a finite element model of the friction plate-retaining spring system is obtained.Using the ABAQUS Explicit Dynamics module to analyze the vibration changes of the system under different friction coefficients and sliding speeds,and output the vibration acceleration data of a node on the contact surface of the frict ion plate and the circlip,and further use LMS Virtual.Lab acoustic finite element The module calculates the acoustic response of the circlip under different influence parameters,and obtains the sound pressure level cloud map of the acoustic field point under different parameters.4.A dynamic model of the friction system is established.Taking into account the advantages and disadvantages of each friction model,the Lugre dynamic friction model is selected as the model for simulating the frictional contact between the friction plate and the retaining spring.The numerical simulation of the system dynamics model is carried out from the aspects of sliding speed,static friction coefficient and viscous friction coefficient respectively,and the dynamic characteristics of the system under the influence of different system parameters are discussed.