Statistical modeling, Sobol sensitivity analysis and optimization of single-tip tool geometrical parameters in the cortical bone machining process.

Machining and cutting of cortical bones are very common and important in the field of orthopedic surgeries. Considerable advances in bone machining are obtained by using computer numerical control machines and automatic surgery robots but still, researches are needed to investigate the effects of machining parameters in bone machining. In this article, for the first time, the effect of geometrical parameters of the single-tip tool on cortical bone machining is studied. The machining parameters included in the investigation are rake angle, back rake angle and side cutting edge angle and the response surface methodology is used to analyze the obtained surface quality according to a second-order regression model. The sensitivity of surface quality to the input parameters was measured by applying Sobol sensitivity analysis and the results are optimized by the Derringer algorithm. Finally, the optimum tool is determined as 15° rake angle, -5° back rake angle and 30° side cutting edge angle. Furthermore, the sensitivity of the surface quality to the input parameters is determined as 52% for rake angle, 31% for side cutting edge angle and 17% for back rake angle.