| With the rapid development of the vehicle industry,various automobile manufacturers have begun to pay more attention to NVH(Noise,Vibration,Harshness)issues.Car closing sound is one of the NVH performance.Therefore,it is of great significance to analyze and improve the quality of closing sound to improve the comprehensive performance of automobile.The dynamic characteristics of automobile door closing can laterally reflect the sound quality of automobile door closing.Exploring the dynamic characteristics of automobile door closing has certain significance for improving the sound quality of automobile door closing.In this paper,the problems existing in the research stage of automobile door-closure sound quality and door-closure dynamics are taken as the research object,and a SUV model developed by an automobile manufacturer is taken as the research object.The objective evaluation parameters of door closing process are obtained by the experimental tests of door closing sound quality,door closing dynamics and door dynamic stiffness.The material parameters of the sealing strip were obtained by combining experiment with simulation.The finite element model of the body door and seal is constructed and the explicit dynamic analysis is carried out to obtain the instantaneous acceleration parameters of the closing process.The door and seal structure are optimized,and the simulation and experimental verification are carried out to explore the process of optimizing the closing dynamics and building a good closing sound quality by changing the door and seal structure.The main contents of this paper are as follows:First of all,a SUV is used as a sample vehicle to carry out door-closure sound quality,door-closure jitter and door stiffness experiments.The loudness and sharpness parameters under different closing speeds were measured;the closing instantaneous acceleration data of the upper corner of the door,the midpoint of the window and the body point above the B pillar;and the dynamic stiffness data of each layout point on the door sheet metal.When the speed is1.2m / s,the loudness is35 sone and the sharpness is2.386 acum.The maximum instantaneous acceleration of closing the upper corner is 9.06 g.Then,the finite element model of this SUV is established by Hypermesh software.The tensile and compression experiments were carried out on the seal sample to obtain the experimental parameters of the seal.Then the experimental parameters were input into Abaqus to fit the sealing strip material parameters.The compression load and compression displacement curves of the simulation analysis of the seal with different strain energy functions are compared to determine the most suitable material parameters of the seal.And take this parameter as the seal material parameter in the dynamic model.Subsequently,the explicit dynamic simulation analysis of the closing process is carried out by Abaqus software to obtain the instantaneous acceleration of the upper corner of the door,the midpoint of the window and the body point above the B pillar in the closing process.The simulation acceleration value of the upper corner of the door is 8.91 g.Its relative error with the maximum value of the closed-door jitter experiment is 1.66 %.The simulation results are in good agreement with the experimental results,which verifies the feasibility of the simulation process.Finally,the modal analysis of the door system is carried out,and the weak parts of the sheet metal are optimized according to the results of dynamic analysis and modal analysis.The compression simulation analysis was carried out on three different cross-section seals and the compression reaction forces were compared.Finally,the damping is pasted on the weak part of the sheet metal and the double bubble tube seal is selected to be assembled into the door system.The dynamic analysis of the optimized model and the door-closure sound quality experiment were carried out.In the process of closing,the instantaneous acceleration value of the upper corner decreases by 1.11 g;in the experiment,the loudness decreased by 2.1 sone and the sharpness decreased by 0.1acum at the closing speed of 1.2m / s.The effectiveness of the optimization scheme is verified.This study can reduce the cost and improve the efficiency of automobile door closing quality development,which has certain engineering value. |
