Synopsis
Aluminum alloy automobile wheels are structural components that play a critical role in vehicle safety and driving performance. Under operating conditions, wheels are subjected to repeated bending moments due to lateral forces generated during cornering, which may lead to fatigue damage over time.
In this study, the effect of mesh element size on cornering fatigue analysis results of automobile wheels manufactured from A356-T6 aluminum alloy was investigated using numerical and experimental methods. The three-dimensional model of the wheel was created using CATIA V5 software, and finite element analyses were carried out in ANSYS software. In the numerical analyses, five different mesh element sizes of 15 mm, 10 mm, 8 mm, 5 mm and 2.5 mm were used. For the generated models, the number of elements and nodes, mesh quality, maximum stress values, and critical stress regions were comparatively evaluated. In the models using 2.5 mm and 5 mm mesh element sizes, the maximum stresses were observed around the bolt holes, with values of 130 MPa and 128 MPa, respectively. In contrast, for the models generated with 15 mm, 10 mm and 8 mm mesh element sizes, the maximum stresses were obtained as 109 MPa, 113 MPa and 114 MPa, respectively, and the critical region was identified at the inner hub of the wheel.
In order to validate the numerical results, short cornering fatigue tests were performed on three different wheels at the Döktaş Test Center. The tests were conducted using a load corresponding to 0.75 times the maximum bending moment calculated according to the ISO 3006 standard and applied for 200,000 cycles. After the tests, penetrant inspection was performed to detect possible surface cracks. As a result of the cornering fatigue tests, fatigue cracks were observed around the bolt holes in all three wheels.
The experimental results were compared with the numerical analysis results. The comparisons revealed that the experimental findings were consistent only with the simulation models generated
using 2.5 mm and 5 mm mesh element sizes. Based on these results, it was concluded that a mesh element size of at least 5 mm should be used in cornering fatigue simulation analyses of automobile wheels in order to obtain reliable results.
