Cutting force is the predominant output variable in rotary ultrasonic machining (RUM). It dictates other output variables, such as tool wear, cutting temperature, edge chipping, etc. It is desirable to develop a mechanistic model to predict cutting force and reveal the underlying cutting tool-workpiece interaction in RUM. Numerous researchers have developed theoretical approaches to predict cutting force in RUM; nevertheless, the combined effects of material removal on cutting force model have not been investigated. RUM has been used for machining rocks in several recent experimental investigations. However, there are no reports on cutting force model for RUM of rocks. This work bridges the gap and reports an improved mechanistic cutting force model. The model is derived based on the ductile mode removal and brittle fracture mode removal of rock under the indentation of a single abrasive particle. The cutting force model for RUM of rocks is then developed by aggregating the effects of all active abrasive particles bonded to the tool end face. Based on this model, the relationships between input variables (tool rotation speed, feedrate, ultrasonic vibration amplitude, abrasive size, abrasive concentration, and tool size) and cutting force are predicted. Experiments have been conducted and the experimental results agree well with the model predicted trends.

切削力是旋转超声加工（RUM）中的主要输出变量。它决定了其他输出变量，例如刀具磨损，切削温度，边缘崩刃等。希望开发一种机械模型来预测切削力并揭示RUM中潜在的切削工具-工件相互作用。许多研究人员已经开发出理论方法来预测RUM中的切削力。但是，尚未研究材料去除对切削力模型的综合影响。在最近的一些实验研究中，RUM已用于加工岩石。但是，目前尚无关于岩石RUM切削力模型的报道。这项工作弥合了差距，并报告了一种改进的机械切削力模型。该模型是基于单个磨料颗粒压痕作用下岩石的延性模式去除和脆性断裂模式去除而得出的。然后，通过汇总结合到工具端面的所有活性磨料颗粒的影响，来开发岩石RUM的切削力模型。基于该模型，可以预测输入变量（刀具转速，进给速度，超声振动幅度，磨料尺寸，磨料浓度和刀具尺寸）与切削力之间的关系。已经进行了实验，实验结果与模型预测的趋势非常吻合。预测输入变量（刀具转速，进给速度，超声振动幅度，磨料尺寸，磨料浓度和刀具尺寸）与切削力之间的关系。已经进行了实验，实验结果与模型预测的趋势非常吻合。预测输入变量（刀具转速，进给速度，超声振动幅度，磨料尺寸，磨料浓度和刀具尺寸）与切削力之间的关系。已经进行了实验，实验结果与模型预测的趋势非常吻合。