Modeling Tire Treadband Vibration

A static tyre was driven radially at a point on its tread band and measurements of the resulting radial tread band vibration were made around the treadband circumference by using a laser Doppler velocimeter. By performing a circumferential wave number decomposition of the measured space-frequency data, the wave propagation characteristics were visualized, In an attempt to understand these experimental results in detail, the tyre treadband was modelled as a ring-like, circular cylindrical shell with air pressure acting on its interior surface. The model makes allowance for general boundary conditions at the lateral edges of the ring, and the sidewall of the tyre is modeled as a distribution of springs and dampers. Both analytical and finite element methods were applied to obtain the vibration response. These solutions were compared with both the experimental result and the response of the infinite length plate driven by point excitation. This shell model was found to explain the propagation characteristics of the waveguide modes that are visible in the experimental results. In particular, the low frequency, flexural wave characteristics associated with finite curvature and which result in efficient radiation of sound were well reproduced. Fast in-plane waves that are potentially significant sound radiators at high frequencies were also well reproduced by this model; the excitation of these modes results from wave coupling within the curved shell. (A) For the covering abstract see ITRD E113232.