A Study On The Smoothness Of The Sliding Doors Of MPV Vehicles

With the continuous development of modern automotive technology,an increasing number of cars are equipped with sliding doors.Sliding doors are a type of sliding vehicle door that have advantages such as smaller external space occupation and larger opening angle compared to traditional hinge-type doors.Therefore,they have been widely used in commercial vehicles and cars.During the long-term use of sliding doors in cars,smoothness issues such as abnormal noise,vibration,and motion sticking may occur.These problems not only reduce passenger comfort but also may affect the safety and lifespan of the vehicle.Using the finite element simulation method to simulate the motion process of sliding doors is an effective way to study the smoothness of sliding door motion.Applying this method to evaluate and improve the performance of sliding doors during the research and development phase can avoid wasting resources and improve the efficiency of the entire design process.This paper takes the sliding door of a certain MPV car as the research object and establishes a smoothness finite element simulation model for the sliding door based on its three-dimensional model according to the modeling process.From the analysis of the simulation results,it is found that the abnormality of the sliding door’s center of gravity acceleration and the force on the leading wheel of the middle arm of the guide wheel can be used as indicators for evaluating the smoothness of the sliding door by reviewing relevant literature and combining engineering experience.The curvature radius of the bending part of the sliding door guide rail,the inclination angle of the middle-lower guide rail,and the position of the shaft pin of the middle arm of the guide wheel are found to have a significant influence on the smoothness of the sliding door.In the early design stage,smoothness tests can be conveniently carried out through shape-fitting door jigs,so a shape-fitting door jig was developed based on the actual car door.By installing the shape-fitting door jig on the actual car and conducting smoothness tests,the feasibility of the shape-fitting door jig was verified by comparing the obtained test data.Comparing the sliding door jig test data with the simulation model data showed a small error,verifying the accuracy of the finite element model.In response to the problem of the significant interactive effects and multiple influencing factors on the smoothness of sliding doors,a method is proposed to establish an approximate model to replace the finite element model and optimize the smoothness of sliding doors by combining the multi-island genetic algorithm.Following the optimization process,techniques such as DOE Latin hypercube experimental design,sensitivity analysis of variables affecting the smoothness of sliding doors,response surface methodology for establishing fitting models,and multi-island genetic algorithm optimization are integrated in a reasonable manner.The optimal results obtained are validated by incorporating them into the finite element model,and the simulation results are compared.The maximum and root-mean-square values of the sliding door acceleration decrease,the maximum value of the leading wheel force of the middle rocker arm decreases,and the smoothness of the sliding door is improved.This paper focuses on the smoothness issue of sliding doors.To address the difficulties caused by the numerous factors and strong interaction effects that affect the smoothness of sliding doors,a precise finite element model is established in this study.Furthermore,a method is proposed that combines the establishment of a fitting model to replace the finite element model and the use of heuristic optimization algorithms to improve the sliding door structure,which provides new ideas for improving the smoothness of sliding doors.Applying this method to the early development process of the sliding door motion system can improve the design efficiency and product performance of the sliding door,and save costs.