Reliable Pre-Design of Commercial Vehicle Rotating Suspension Components

Nowadays, durability analyses of rotating suspension components are carried out by FEM. A reliable pre-design requires realistic customer usage conditions. One of the most important issues is the load transfer from the tire to the rim, which is decisively influenced by the kinds of tire construction, which differ depending on the vehicle type. The corresponding load conditions and load spectra also have to be taken into account. A comparison of numerical results and experimental sign-off tests from wheels and hubs in the biaxial test facility (ZWARP) – developed by the Fraunhofer LBF – is only possible by considering the issues described above.

This paper shows a reliable method for deriving a realistic load input at the rim using a heavy truck wheel as example. A physical tire model is derived from strain gauge measurements on wheels and a inverse FEM calculation. Tire models and corresponding parameters are integrated in the LBF.WheelStrength and LBF.HubStrength. Additionally the software includes all customer usage conditions needed (load data, design spectra). These tools have been developed to simulate physical tests. The software calculates a local Required Fatigue Strength (RFS), for which the individual locations of the components are optimally dimensioned. These RFS values can be compared with strength data elaborated from fatigue tests on actual structures and include specific manufacturing influences. Subsequently such a numerical fatigue evaluation is carried out for verification of the newly developed commercial vehicle tire model. In the paper numerical and experimental results are presented displaying the accuracy of the method.

With this technique a reliable approach for pre-design of commercial vehicle wheels and hubs has been created. The development process of wheels and hubs is substantially improved and optimized using the above-mentioned method.