Identification of complex moduli for rubber compounds by minimisation of the error between measured and FE-modelled velocity profiles

Paper in proceeding, 2006

For all research that involves understanding of the contact between tyre and road surface, knowledge of the tyres dynamical material properties is of importance. A method for identification of the complex moduli, i.e. dynamic stiffness and damping, of rubber tread materials is presented. The method is based on a velocity profile match between FE-models and measurements. The measurements are conducted on beam-like samples with a laser Doppler vibrometer, giving only insignificant errors due to measurement interference. The specified material parameters are updated in the FE-model in order to minimise the sum of the squared errors between measured and modelled velocity data. This optimisation problem is solved with a gradient descent algorithm, where a one-dimensional wave model provides initial values. This identification method may be used at higher frequencies for highly damped materials, and do not show the limitations of methods only evaluating the material at resonance frequencies. The method gives a consistent identification in a wide frequency range.