Simulation of the Experimental Proof Out of Wheels and Hubs 2002-01-1202
For the life and fatigue strength evaluation of structural components during the development phase Finite Element analyses are performed to calculate the representative stresses under the operational conditions. Besides the usual requirements on the set up of models with their boundary conditions as well as the performance of the computations it is decisive to introduce meaningful service load conditions in an effective way. Finally the results need to be correlated to the strength of the structures which however is determined by the material, the local design and most important the manufacturing. Within this paper a concept for the computational durability evaluation is presented for wheels, hubs and bearings, fully simulating verified experimental methods. Physical tire models derived from measurements of global tire deformations and strains on the wheel are used to achieve a realistic load input at the rim. Loading data for the distinguished physical load conditions and the respective spectra of the expected customer usage conditions are included as a proposal. The calculation of the stress time histories results from the simulation of rolling under the various load conditions. The damage calculation is based on generic fatigue strength data. As a result of the analysis the required local fatigue strength (RFS), for which the individual locations of the wheel would be optimally dimensioned are presented. The evaluation of the computation is done by comparison of the calculated required fatigue strength with strength data elaborated from fatigue tests on the actual structures, including the specific influences of the manufacturing. In future such data may be given by the simulation of the manufacturing itself in combination with appropriate testing. Thus a powerful tool is described making use of many years of experience with road load data acquisition, with experimental stress analysis and with fatigue and proof out testing.