Design And Analysis Of Front Sub-frame Test Bench System Based On Virtual Method

With the development of automobile industry and the perfect of laws and regulations,each country now is putting forward higher and higher requirement for the safety of vehicle.Durability and anti-fatigue properties of automotive components has been paid more and more attention,also durability test has been the most crucial link during the process of car development.Durability and anti-fatigue properties is an important indication for the quality of the vehicle,and it's also the premise of subsequent structure optimization.At present,domestic durability test mainly focus on the outdoor test with long time and much cost like the customer road test and the field road test.Because of the rapid development of IT computing technology,CAE has gradually become the main trend using in durability test for automobile components.With the help of virtual simulation technology,engineers can understand and evaluate the whole fatigue durability working characteristics of the product as soon as possible,then make corresponding improvement and optimization.In this paper,we make the front sub-frame as the research component.First of all,set up the finite element model of the test bench including the sub-frame component and the six-column fixture,and verify the accuracy of the CAE model from static and dynamic aspects,according to the static stress contour result and strain rain-flow analysis result,we can find that the finite element model of sub-frame test bench system has a high accuracy.It can make a good preparation for the subsequent analysis,then do the static stress analysis and virtual fatigue analysis,gather the virtual strain-time signal and calculate the damage of the predicted dangerous location,so that we will have a comprehensive understanding about the component' fatigue characteristics.About the phenomenon that fixture fatigue failure occur often during the indoor bench test,we explored the reason with simulation method by changing the size of section to change the stiffness of fixture,By doing so we can know well about the overall influence of the fixture stiffness to the test bench system,find out the optimal designing size of fixture section.The results show that the fatigue durability simulation technology can effectively help designers found the problem of products in the early designing stage,get rid of the test constraints of physical prototype.This method can reliably simulate the whole working characteristic of the test bench system,which can effectively reduce the time of experiment,save the total cost and improve the competitiveness of products.The method of virtual fatigue analysis process summed up in this paper can be used for other automobile component just like front sub-frame.The simulation result is in a higher degree consistent with the bench test results can ensure the accurate designing for these components.