Abstract
Prior to the simulation, the edge fracture test of “A” type single grain was conducted and the fracture characteristics obtained were compared with those of “WA” type grain reported in the previous paper. The fracture onset probability is small for “A” grain regardless of edge shape, while it is large for “WA” grain except the flat type edge. Transition probability p99 that the flat type edge changes again to the same one after fracture, is quite small for “A” grain in contrast with the value of almost unity for “WA” grain. Next, simulation analysis of the sequence of edge fracture and edge shape transition during surface grinding, in which grain depth of cut varies with time and location, was carried out with Monte Carlo method. Since the fracture onset and the edge shape transition have Markov property, they were determined independently of their history by generating random numbers in accordance with the probability distributions of the onset and the transition. In the analysis, the height loss of grain tip was also taken into account. For “WA” wheel, it is found that the grain depth of cut is reversely proportional to the fracture onset probability, hence the flat type edge exists in the outer layer of the wheel and contributes to the stock removal greatly. On the other hand, the edge sharpness is kept up for “A” wheel since the flat type edge often changes to other sharp edges due to the small p99.
