Lightweight Design and Construction of Aluminum Wheels

In this paper the lightweight design and construction of road vehicle aluminum wheels is dealt with, referring particularly to safety. Dedicated experimental tests aimed at assessing the fatigue life behavior of aluminum alloy A356 - T6 have been performed. Cylindrical specimens have been extracted from three different locations in the wheel. Fully reversed strain-controlled and load-controlled fatigue tests have been performed and the stress/strain-life curves on the three areas of the wheel have been computed and compared. The constant amplitude rotary bending fatigue test of the wheel has been simulated by means of Finite Element method. The FE model has been validated by measuring the strain at several points of the wheel during the actual test. From the FE model, the stress tensor time history on the whole wheel over a loading cycle has been extracted. The Sines fatigue criterion and the critical plane approach have been adopted for computing the fatigue life of the wheel and results have been compared with the fatigue tests on the actual component. Both of the two criteria underestimate the life of the component. A proper criterion to assess such a discrepancy is proposed. The process of wheel construction which guarantees the repeatability of experimental tests is highlighted.