Analysis And Optimization Of Front Suspension Leaf Spring Of An Agricultural Transport Vehicle

According to user feedback of a certain agricultural transport vehicle,the front suspension leaf spring often suffers from instability and fracture during service,which seriously affects driving safety and increases later use costs.In addition,the original structure is designed based on experience and is over-designed,resulting in excessive quality.Material waste runs counter to the country’s energy-saving and emission-reduction policies for vehicles,so it is redesigned to meet usage requirements.This article first verifies whether the structural parameters of the original car leaf spring are reasonable from the theoretical level,and performs theoretical calculations on the performance from the perspective of material mechanics.Establish a parametric threedimensional model in UG according to the original size data given by the manufacturer,and then import the model into ANSYS Workbench to establish a finite element model consistent with the actual force,and analyze the static characteristics,fatigue reliability and dynamic characteristics of the leaf spring.Performance is calculated and analyzed in different simulation modules.After that,the accuracy of the finite element analysis results was verified through the leaf spring bench test,while ensuring the accuracy of the finite element model.The test results show that the established finite element model has high accuracy and can replace the original real model for calculation.Finally,based on the response surface approximation model and the NSGA-II algorithm,the deterministic and 6σ robustness multi-objective optimization of the leaf spring is carried out.First,the deterministic optimization is carried out,and the target is the smallest mass,the largest full-load bending stiffness and the smallest maximum equivalent stress,and the fatigue life,The second and fourth order resonance frequency,and the strength under forced displacement are constraints.Although the optimization results can meet the use requirements and performance goals,but for the harsh operating conditions of agricultural vehicles Fluctuations and errors in the leaf spring manufacturing process may cause its performance constraints to exceed its allowable value.In the case of poor σ quality and low reliability,robustness optimization is performed on the basis of deterministic optimization,and the results show that each performance is uniform.There has been a substantial improvement,and the robustness has been improved.