Introducing abrasive wear into undeformed chip thickness modeling with improved grain kinematics in belt grinding

The undeformed chip thickness (UCT) is an essential indicator in understanding the belt grinding mechanism, especially in relation to surface roughness. However, abrasive wear has not been involved in the above modeling studies, even though it always influences the grinding process. In this paper, the evolving grain height distribution, which is governed by the accumulative active grain group, is first quantified using a gamma distribution. Then, based on the geometric analysis of the compliant contact area, improved grain kinematics considering non-uniform grain height is proposed. Finally, based on the above findings, an improved undeformed chip thickness model is established and experimentally validated. The calculated results based on the model show that undeformed chip thickness value approximately obeys a normal distribution at various wear stages unlike a Rayleigh distribution in rigid wheel grinding. The mean and variance of the distribution generally decrease with increasing grinding time, which is supported by the transformation from spiral chips to fragmented chips. Surface prediction is performed to help experimentally verify the reliability of the proposed model, where results illustrate that the predicted and measured roughness exhibits a similar decreasing trend with increasing active grain percentage and grinding time.