Simulation Analysis And Optimization Of Ride Comfort On Rigid-flexible Coupling Vehicle Model Of Heavy Tractor

The ride comfort is an important criterion for evaluating driving smoothness of vehicles.Poor ride performance of heavy tractor will lead to many problems,which will affect driving safety.Ride comfort analysis is an important part in the process of vehicle development.The simulation analysis of ride comfort on heavy tractor can not only evaluate the comfort of the existing model,but also provide a reference for its optimization design.Vehicle modeling is the key step of ride comfort simulation analysis.In order to improve the modeling accuracy and analysis accuracy of the model,the rigid-flexible coupling model of the whole vehicle of heavy tractor is established according to the theory of multi-body dynamics,which is verified based on the test data,and the vehicle ride comfort is analyzed with simulation and optimized.In this paper,a heavy-duty tractor is taken as the research object.Firstly,the air spring,cylinder shock absorber and engine mount are tested on the bench to obtain the test data.the test results are fitted mathematically to obtain the more accurate characteristic parameters.Secondly,according to the multi-body dynamics theory and relevant data,subsystem models of the heavy-duty tractor are established by using ADAMS/car.Then build a rigid-flexible coupling model of the whole vehicle.In order to establish the model of cab and frame,the method of flexible body is adopted.The finite element model is firstly established in the finite element software,and the finite element model of cab and frame is verified by finite element modal analysis and modal test.The available finite element model is obtained.Then,the finite element model is put into Adams/car to generate the flexible body model of cab and frame.Finally,referring to the relevant provisions of the national standard of road test,ADAMS/car ride module is used to establish the road spectrum file,and according to the relevant national standards of ride comfort,the ride comfort of the heavy tractor vehicle under multiple working conditions is simulated.A comprehensive evaluation was made on the ride comfort of the driver's position,which taking into account the actual working conditions.The paper has considered the influence of the flexible cab and the flexible frame on the ride comfort of the vehicle,which has verified the necessity of the rigid and flexible coupling.Finally,the main factors that affect the ride comfort of the heavy tractor are analyzed.By using Adams/insight,and taking the weighted acceleration root mean square value above the seat cushion of the heavy tractor as the optimization objective function,the characteristic curves of several elastic parts with greater influence is selected as the design variables,and DOE experimental design is adopted to realize the joint optimization of multiple parameters.After optimization,the ride comfort of the sample vehicle was improved by 14.9%,so as to achieving the ultimate goal of improving the ride comfort of the original vehicle.