Research of mechanical model based on characteristics of facture mechanics of ice cutting for scientific drilling in polar region
Abstract. Scientific drilling in polar regions plays a crucial role in obtaining ice cores and using them to understand climate change and to study the dynamics of the polar ice sheet and its impact on global environmental changes (sea level, ocean current cycle, atmospheric circulation, etc.). Mechanical rotary cutting is a widely used drilling method that drives the cutter to rotate to cut and drill through ice layers. It is necessary to conduct in-depth research on the brittle fracture behavior of ice and mechanical model, and analyze the factors and specific mechanisms (cutter’s angle, rotation speed of the drill bit, and cutting depth) affecting cutting force for the rational design of ice-core drill system, improving the efficiency of ice-core drilling, and ensuring the drilling process smoothly. Therefore, in this paper, the process of ice cutting was observed, the fracture mechanics characteristics of ice cutting process wad analyzed, the formation process of ice chips was divided into three stages, and the mathematical model for the cutting force was established based on the observation results. It describes the damage conditions of ice failure and points out the influencing factors and specific influencing laws on cutting force. Furthermore, the cutting force generated under various experimental conditions was tested. Based on typical real-time data curves of cutting force, the characteristics of cutting force were analyzed during the cutting and drilling process. Based on the comparison results of the average cutting force, the influence mechanism of various parameters on the cutting force is obtained. This proves the correctness of the mathematical model of the cutting force and provides a theoretical reference for the calculation of cutting force during ice cutting and drilling in polar regions.
Viewed (geographical distribution)