Determination of friction coefficients, brush contact arcs and brush penetrations for gutter brush–road interaction through FEM

A 3-D, dynamic, non-linear Finite Element Model (FEM) involving contact is used to determine apparent coefficients of friction, mu, for the interaction between the bristles of a flicking brush for street sweeping and concrete. Also, brush contact arcs, as well as suitable brush penetrations as functions of the debris height, are determined for cutting and F128 brushes. Available experimental results are used to determine the coefficients of friction. The bristles are modelled through beam elements, which are subjected to inertia forces. The results suggest that the model is valid and that the coefficient of friction affects the brush vertical force in the flicking brush, but it does not significantly affect its counterpart in the cutting brush. The results also indicate that the coefficient of friction for the flicking brush depends on the sliding velocity, v, and these were fitted to an exponential mu - v curve