Mathematical Modeling and Sensitivity Analysis of Effective Parameters on Temperature in Ultrasonic Assisted Drilling of Cortical Bone

The use of ultrasonic vibrations to reduce the temperature in bone drilling is one of the most important advanced processes that has attracted the attention of bone surgeons. Therefore, the study of temperature behavior in the ultrasonic-assisted drilling process and the prediction of temperature behavior have an important effect on improving the use of this method in orthopedic surgery. In this research, the influence of process parameters on change in the temperature was studied using response surface methodology and data analysis. Data analysis was carried out to find the effect of process factors such as rotational speed, feed speed, and ultrasonic vibrational amplitude and their interaction on the temperature. Moreover, using the statistical method of Sobol sensitivity, the effect, and sensitivity of each input factor on temperature were studied. The results show that the use of ultrasonic vibrations reduces the temperature, and rotational speed (%48), vibrational amplitude (%33) and feed speed (%19) had the greatest effect on temperature in ultrasonic-assisted bone drilling, respectively. As a result, the use of ultrasonic vibration can reduce the dependency of process temperature on the feed speed, and thus make it possible to perform surgery in a shorter time. The minimum temperature is 37°C at the rotational speed of 500rpm and the feed speed of 20mm/min and the vibration amplitude of 15μm.