A novel material removal rate model based on single grain force for robotic belt grinding

Abstract

Modelling of grinding force and material removal rate (MRR) has been widely investigated for wheel grinding which often has a preset cutting depth, but is rather lacking for sand belt grinding. For robotic belt grinding where the normal force often remains constant, the cutting depth of individual grain varies as the abrasive grains wear with grinding time increasing. It is, therefore, a challenge to accurately predict the tangential force and resulted MRR, and subsequently control the finish profile. This paper develops grinding force model and material removal rate model based on single grain force for robotic belt grinding. It divides the whole grinding process into three stages: initial stage, steady stage and accelerated stage, based on the degree of grain wear, analyses the grinding force of rubbing, ploughing and cutting effects and MRR at each stage. By studying the distribution of grains and penetration depth of each grain, the grinding force and MRR are calculated. Experimental work on stainless steel 304 shows that the maximum errors of the tangential force prediction is 10.9% and that of MRR is 14.4%. The proposed models not only reveal the grinding mechanism but also predict the grinding force and MRR.