Orthogonal Cutting Of Bone

"The cutting of bone has been undertaken for many centuries. Research in this area is contnually progressing to achieve an efficient cutting action while reducing recovery time and rauma to the patient. Orthogonal cutting is defined where the cutting edge of the tool is set in a position that is perpendicular to the direction of relative work or tool motion. The failure mechanisms involved in the cutting of bone, their direct relationships to cutting tool geometry and cutting direction for orthogonal cutting are not accurately defined or quantified. A study of the orthogonal cutting behaviour of bone initiated in the hope of understanding these failure patterns is presented here. Quantitative results showing the relationship between cutting force and rake angle for each of the three mutually perpendicular cutting directions used in this work form the main part of this study. The effect of increasing the depth of cut has also been addressed as has the effect of increasing the cutting speed. It has been shown that cutting force is directly proportional to the depth of cut and the mechanical properties of bone contribute significantly to the cutting force for low cutting speeds. Chip formation characteristics were also studied. From this study the chip type was found to depend entirely on the cutting direction used. To allow a greater understanding of the failure mechanisms present, a computational model using Finite Element (FE) software was developed where the orthogonal cutting process was modelled. An experimental analysis accompanied by computational modelling has outlined and highlighted how many cutting variables such as cutting direction, cutting speed, depth of cut and specific tool geometry are all significant contributors to the orthogonal cutting behaviour of bone."