Numerical Analysis of Tilted Cutting and F128 Brushes

Road sweeping is an essential service that has to be conducted for public health, as well as aesthetic purposes. In many countries, sweeping vehicles are used for this activity. They usually comprise a gutter brush that sweeps the debris that is located in the road gutter. This work studies the performance of two kinds of gutter brushes: a cutting brush and a flicking (F128) brush. This is carried out by means of a 3-D dynamic, nonlinear Finite Element (FE) brush model developed by the authors. In this model, inertia forces are applied to the bristle, and its clamped end is fixed. Consequently, the surface (road) is rotated, translated, and raised. Bristle-road interaction is modelled as flexible-to-rigid contact. In particular, the aim of this article is to compare the performance of a conventional brush and a brush rotating at variable speed. As brushes normally work tilted, FE analyses are carried out for tilted cutting and F128 brushes, rotating at speeds that fluctuate at different frequencies. It is concluded that brush oscillations have a significant effect on bristle tip velocities and bristle-road forces. Also, at certain frequencies, oscillations seem to improve sweeping performance of the F128 brush. However, they do not appear to improve significantly the performance of the cutting brush.