Development And Verification Of Steering Knuckle Test Based On Macpherson Structure

The steering knuckle is a very important safety component in an automotive system,and its shape and structure are extremely complicated.With the development of lightweight vehicles,the traditional iron steering knuckle is gradually replaced by the aluminum alloy steering knuckle.Its main function is to withstand the front load of the car body to ensure stable driving.The knuckle is repeatedly impacted by various loads such as road surface and restraint during the running of the car.The load changes continuously with the working conditions,and cracks or fractures may occur.The structural strength and fatigue life of the knuckle must be analyzed.Therefore,the steering knuckle test is extremely important for the analysis of the steering knuckle.This paper took the MacPherson suspension knuckle as the research object,and studied the design of the knuckle test rig.It mainly completed the following aspects:Based on the technical analysis of the MacPherson suspension,a schematic diagram of the McPherson suspension mechanism is established,and the constraint mode and function of the steering knuckle in the MacPherson suspension are analyzed.Analyzing the McPherson suspension restraint mode,and applying the CATIA software to extract the hard point coordinates of the MacPherson suspension was to provide a basis for the design of the steering knuckle test bench.The knuckle test conditions were inductived.The steering knuckle test standard were studied.Determining the position of each component of the test rig according to the extracted hard point coordinates,and the McPherson suspension structure are simulated according to the fixture design requirements.Three-dimensional model of the test bench was built with CATIA.The ANSYS Workbench was used to perform finite element analysis on key components of the test bench to meet the test strength requirements.The standard parts of the test bench were improved to facilitate the assembly and test operation of the gantry.The test was verified by a steering knuckle of a car.The feasibility of the test rig was verified by the static load test and the fatigue test.The cracks which occurred during the knuckle test verification process were analyzed.Lastly,the improved steering knuckle was tested and verified.The static load test result and the durability test result were respectively benchmarked with the corresponding simulation results.Error analysises behind the test and the simulation were performed.