Wheel rims and wheel hub bearings are critical components of Heavy Commercial Vehicle (HCV) suspension systems and are subjected to extensive fatigue loading throughout their operational life. Actual loading conditions on wheels are a combination of radial loads (vertical loads) and cornering loads (lateral loads) acting simultaneously and are directly influenced by payload and road conditions. Currently for Indian usage, there are test guidelines [1] only for separate uniaxial Radial Fatigue Test (RFT) and Cornering Fatigue Test (CFT) for wheel rims which might not represent realistic combined loading conditions, and no generic guidelines are available for testing of wheel hub bearings. There is a biaxial test guideline defined for European usage scenario, but no guidelines defined for Indian usage scenario [5] Thus, there was a need to define test guidelines for biaxial fatigue testing of wheel rims and wheel hub bearings, based on data acquired for Indian roads and usage conditions, which can serve as a basis for durability evaluation of these components
The results of this paper use a novel approach to provide guidelines for biaxial testing of wheel rims and wheel hub bearings, both of which are safety critical suspension components. Extensive road load data acquisition (RLDA) is carried out on Heavy Commercial Vehicles (HCVs) from 16 Ton to 55 Ton capacity. This data is then further normalized and mixed as per a target duty cycle mix for a defined life of 10 Lac kilometer. Further this data is then analyzed in wheel revolution history and two-dimensional histograms (joint distributions) are created for radial and lateral loads. Based on this data and using damage theory a test cycle is created that can be used for biaxial testing of wheel rims. For wheel hub bearings, an accelerated test cycle is created considering the joint radial and lateral load distributions and contact stresses between bearing surfaces.