Fatigue Life Analysis Research Of Aluminum Alloy Wheel Hub For Heavy Automotive Vehicles

As the important component of the vehicle, the reliability of the wheel is directly related to the safety of the vehicle. With the superior performance, low pressure casting of aluminum alloy wheel hub has been widely used in the passenger car instead of steel wheels.And it has been used in the heavy vehicle is still just beginning, but it has a broad application prospect in the future. At present, the study of aluminum alloy wheel hub is mainly focused on the wheel hub with a small size or steel wheel used by the passenger car, the studied of the fatigue life under service condition for large size low pressure casting aluminum alloy wheel hub used by heavy vehicle is less.In order to explore the fatigue characteristics of large size low pressure casting aluminum alloy wheel hub for heavy vehicles,with reference to relevant fatigue performance test requirements,the method of FEA and fatigue analysis have been used to establish the test simulation of a hub of dynamic bending and dynamic radial fatigue,maximum stress and fatigue damage location have been predicted by using static analysis method. By comparing simulation results with the actual, the result shows that:In the process of dynamic fatigue, logarithmic life between the wheel vent is relatively low, but it meets the national standard minimum cycles. Due to the particularity of its structure,the damage of large size low pressure casting aluminum alloy wheel hub will not occur in bending fatigue test. In the process of radial fatigue, rim has a relatively large deformation. Compared small size aluminum alloy wheel hub with large size steel wheel, stress value to the outer rim inside connection flange fillet is relative taller and the wheels did not appear stress concentration between air vents;The location of wheel damage appears at the outer rim connection flange with rounded corners, the prediction coincides with the actual wheel damage location.To get accurate fatigue life, stress and load process need to be corresponding at the dangerous parts. At the same time,the in homogeneity of the different parts of the material on the wheel hub reduces the fatigue from the rim to wheel order,the fatigue life also follows this rule at the same stress under the condition. The fatigue damage parameter should be able to reflect the stress state of dangerous parts when it selected. The principal stress should be selected as fatigue damage parameter where the dangerous parts appear near the wheel bolt hole or on the outer rim; the predicted life is closer when equivalent stress or principal stress have been chosen as fatigue damage parameter where dangerous parts appear on the spokes.The wheel hub will be optimized at structure and molding process from two aspects of influence, the fatigue life of parts(stress level, material fatigue performance). The results show that the outer rim connection hub within the radius of fillet should be between 26 mm ~ 26.5 mm; Low pressure casting molding process can be improved appropriately(cooling rate, cooling time, mold temperature, cooling way, initial casting temperature, etc.),which makes the wheel can satisfy the requirements in the fatigue test.