Test setup for tire/road noise caused by road impact excitations: first outlines

This paper describes the design and first experimental results of a novel test setup to measure the impact response of a rotating tire. The test setup is based on a tire on tire principle, which requires less space than a classic drum (rigid rotating cylinder). The setup is used to analyse mechanisms of tire/road noise during road impact excitations, such as a cobbled roads, joints of a concrete road surface, railroad crossings,... The noise that is radiated from a tire strongly determines the passenger acoustic comfort and the traffic noise. Besides the radiated noise, the spindle forces induce vibrations that generate noise in the passenger compartment. Typical for a road impact excitation are a short duration tactile spike (shock) and a short duration noise spike (impact boom) experienced by a passenger. A series of test are performed with different driving speeds, cleat dimensions and inflation pressures. The test results are used to identify and quantify the mechanisms of noise generation during impact excitations with respect to the different parameters. These analyses will contribute to the future development of tire models to simulate the acoustic and structural response to road impact excitations.