Prediction Model Of Temperature Distribution In Cortical Bone Drilling And Study Of Heat Affected Zone

Bone drilling is a basic operation in medical orthopedic surgery,and it is inevitable that a large amount of heat will be generated during the drilling process.Bone drilling is a semi-closed process,and the heat transfer coefficient of the cortical bone is low,which causes heat accumulation near the borehole and temperature rise.Higher temperatures can cause thermal damage to bone tissue near the borehole,and severe thermal damage can lead to osteonecrosis,which is contrary to the original intention of orthopedic surgery.Therefore,obtaining the temperature distribution of the cortical bone drilling area is of great significance for medical bone surgery.The current temperature measurement method can not accurately obtain the temperature distribution near the cortical bone drilling area.Therefore,based on the heat transfer theory,the mathematical model of temperature distribution prediction in the process of cortical bone drilling is established,and the finite element software(ABAQUS)dynamic simulation is used.The cortical bone drilling process was carried out,and the temperature distribution and heat affected zone during the cortical bone drilling process were analyzed.The main contents of the paper are as follows:(1)By analyzing the distribution and source of heat in the process of cortical bone drilling,the heat source model and its motion law in the process of cortical bone drilling are obtained.Based on this,the thermal differential equation in the process of cortical bone drilling is established and the solution is given Single value condition.(2)The heat source method is used to solve the temperature distribution of the static point heat source,and then the temperature distribution of the moving point heat source is derived.Finally,the temperature distribution prediction model in the cortical bone drilling process is obtained,and the cortical bone drill is derived based on the conjugate gradient method inversion.The energy partition coefficient during the cutting process.(3)A cortical bone drilling test platform was built to verify the temperature distribution prediction model during the cortical bone drilling process.According to the prediction model,the cortical bone temperature distribution along different depths and different radial distances and different drilling conditions were analyzed.Spindle speed,feed rate,drill diameter)effects on cortical drilling temperature.(4)The heat affected zone was defined.Based on ABAQUS,a three-dimensional finite element model of cortical bone drilling was established.The cortical bone drilling process was simulated dynamically and its temperature variation law and heat affected zone were observed.The established temperature prediction model was used to calculate the specific drilling conditions.Under the heat affected zone.