Optimization Design And Research On The Structure Of A Monorail Sliding Door

The sliding door of monorail push-pull vehicle is an important component of the vehicle.When the vehicle is subjected to different degrees of load during driving,it will cause excessive deformation of the door locally,resulting in insufficient rigidity of the door,resulting in poor door closing,poor sealing of the sliding door,air leakage,rain leakage,vibration,abnormal noise and other problems,which will have a significant impact on the aesthetics,safety and NVH performance of the vehicle.Therefore,this paper focuses on the lightweight research and exploration of the sliding door structure of a new type of sliding door researched by an automobile company for its annual model.The main contents are as follows:(1)Finite element modelling of sliding doors.First,according to the geometric model of the sliding door,the finite element model of the sliding door structure of this type of vehicle is established through the finite element software,and the vertical stiffness,torsional stiffness,window frame stiffness,anti concave stiffness and modal analysis under the free working condition are solved by using the material nonlinear and geometric nonlinear static dynamic analysis.Then consult the data and the reference of the same vehicle model at home and abroad,and the benchmarking analysis results show that under the modal analysis,its frequency will not have resonance with the vehicle body,meeting the design requirements;However,some of its stiffness values do not meet the design requirements.After the structural improvement of the sliding door,The results of the recalculations show that the design requirements are met,with some resistance to torsion and material deformation.(2)The modal analysis and modal test of the sliding door are analyzed and verified.After the structural improvement of the sliding door,all the performances of the sliding door meet the design objectives.As a result,depending on the theories of the finite element analysis,the free mode of the model is analyzed by finite element software and the vibration and noise detection and analysis equipment LMS is used.The modal test analysis of the solid sliding door verifies the accuracy of the computer simulation.Through the comparative analysis of the results,When the error range is acceptable,which verifies the accuracy of the finite element simulation.(3)Multi-objective lightweight design.According to the analysis results of the improved structure,this type of sliding door has a certain optimization space.Considering that there are many design variables and some variables have a small impact on the structure,the key components are selected by introducing the analysis method of relative sensitivity.Then,the plate thickness of 12 key design components is selected as the design variable,and the parametric finite element model of multiple working conditions is built in the parametric software Hyper-study.Through the Hamersley DOE test design,a large sample space is obtained.At the same time,it is found that the mixed radial basis function(RBF)The least squares method(LSR)and the moving least squares method(MLSM)fit the approximate model of the parametric finite element model with the highest accuracy.Finally,aiming at the approximate model of the parameterized finite element model,the 794 sets of Pater solution sets obtained by the multi-objective genetic algorithm MOGA iteration 6714 times were optimized.The data of the Pater solution sets were made multi-objective decision using the entropy weight-gray correlation analysis method,and the most suitable optimal solution was screened out.(4)The optimized results show that the mass of this type of automobile sliding door after parametric optimization is reduced by 6.8%,and its stiffness and strength performance still meet the design requirements after optimization.Therefore,it has certain reference value to carry out structural optimization design and research on this type of sliding door.