Study On Fatigue Property Of Hydroforming High Strength Steel Rim

Wheel is an important part of the car,its quality is directly related to the safety of the car.Automobile steel wheel hub is mainly composed of rim and spoke.As the main load-bearing component,rim is generally formed by plate welding,multi-pass rolling and expansion finishing.The whole manufacturing process is complex,and the efficiency is low and the cost is high.At the same time,due to the process limitation,the rim is generally made of medium strength low alloy steel,and the structure is complex Because of the miscellaneous rim parts,it can not further meet the requirements of lightweight.In this study,s500 mc steel with higher strength is used to replace the original medium and low-grade steel,combined with the new technology of internal and external pressure compound forming hydroforming to manufacture steel rims,so as to achieve the maximum lightweight of rims and reduce the processing procedures from two aspects of material and process.In this paper,high strength steel wheel rim was successfully manufactured by hydroforming with internal and external pressure.After forming,the thickness distribution of the rim will be uneven.According to the actual distribution of rim wall thickness and material thinning,the fatigue performance of hydroforming automobile rim is analyzed by combining finite element simulation analysis with experimental verification.Firstly,the three-dimensional model of rim is established in CATIA software,and then the finite element model is established by ABAQUS software.The stress-strain analysis of rim bending fatigue simulation and radial fatigue simulation stress-strain analysis are completed.Finally,the stress analysis results are imported into FE-SAFE software for rim bending fatigue life analysis and radial fatigue life analysis.The results show that the high strength steel rim meets the requirements of hydraulic forming.The bending fatigue test and radial fatigue test were carried out on the rim with fatigue test-bed.The test results show that the hydroforming high-strength steel rim meets the requirements of fatigue performance.Compared with the simulation analysis results,the location of the failure point is the same,which verifies the accuracy of the simulation analysis,and provides a new idea for rim forming and further lightweight.