| With the development of society,vehicle play an increasingly important role in people’s daily lives.Vehicle brings high-efficiency and convenience to people,but also produces hidden safety hazards that cannot be ignored,which involves the fatigue of auto parts.According to incomplete statistics,most traffic accidents are caused by fatigue failure of structural parts on automobiles.If the parts break during the normal driving of the vehicle,it will inevitably bring inevitable disasters.Suspension,as an important part of an automobile,is a key component that connects tire and bodywork and transmits interaction forces.It plays an extremely important role in the safe operation of automobiles.Therefore,the research on the fatigue life of automobile suspension has extremely important significance.This article takes the rear guide arm air suspension of a certain type of bus as the research object,uses UG software to systematically model the guide arm air suspension,and imports the established solid model into Hypermesh for finite element meshing.In order to study the dynamic characteristics of the guide arm air suspension,the free-mode and pre-stress modal analysis of the guide arm suspension was done in ANSYS-Workbench;In order to ensure the accuracy of the established finite element model,the results of the modal test and the suspension free modal analysis are compared and verified,and the two are basically in agreement.The frequency of the analysis modal and the test modal is within the specified error range,which verifies the accuracy of the model built.Secondly,the ADAMS software is used for dynamic simulation of the guide arm air suspension;The hard point coordinates are obtained through the CAD model to establish the dynamic analysis model of the guide arm suspension system.According to the actual situation,the vehicle’s rapid acceleration condition and maximum lateral force carry out the dynamic simulation analysis of the suspension under the three extreme working conditions of the working condition and the impact load,and obtain the limit load distribution of the suspension under these three extreme working conditions;In accordance with the load obtained by the simulation,the suspension is sequentially performed in the Workbench software static strength check.The stresses of the suspension under the three extreme working conditions did not exceed the yield strength of the material,which met the structural strength requirements.Combined with the use properties of the vehicle,the filtered white noise is used as the input of the simulated road surface under the selected road conditions,and the random load spectrum of the suspension structure under the road surface is obtained through dynamic simulation.Finally,based on the static strength analysis,the maximum stress concentration area of the suspension is found.In order to better study the fatigue characteristics of the suspension structure,the fatigue life is calculated and analyzed.The S-N curve of 50 CrVa material is reconstructed by material property parameters,and the S-N curve of components for fatigue analysis is derived through reasonable correction and approximate estimation;The random load spectrum obtained by dynamic simulation is combined with the linear damage accumulation criterion as the basis N-Code software was used to predict and analyze the fatigue life of the suspension structure.The analysis found that the life of the suspension was greater than the minimum life standard required in the project,which met the design requirements;the accuracy of the prediction results was verified through the comparison of the design suspension fatigue test.Based on the analysis of structural strength and fatigue characteristics,the optimization design of the guide arm structure was improved,and its quality was reduced by 4.3% on the premise of ensuring structural safety and other performance,and the structure was lightened. |
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