Impacts on beams: Uncertainty in experiments and numerical simulation Werner Schiehlen, University of Stuttgart, Stuttgart, Germany Robert Seifried, University of Stuttgart, Stuttgart, Germany

ABSTRACT: Impacts on beams result in large rigid body motions and small structural waves. Such mechanical systems are often modeled as multibody systems to describe the large nonlinear motion where the impacts are treated by the coefficient of restitution. The coefficient of restitution is considered as deterministic number depending on the material, the shape and the velocity of the colliding bodies. However, in experiments and computations it was observed that for a sphere striking a beam the coefficient of restitution is uncertain due to multiple impacts resulting in chaotic behavior. For the evaluation of the numerical and experimental data a statistical approach is proposed providing mean value and dispersion of the coefficient of restitution depending on four classes of the velocity. It is shown that these parameters allow characterizing the uncertainty.