Aramid honeycomb has extensive applications in the aerospace and rail transportation industries. Ultrasonic cutting (UC) with the straight blade (SB) is an advanced technology used for the profile machining of honeycomb materials. Cutting force is an important factor affecting machining quality, and its accurate modelling is particularly important. However, SB is a flake tool, and chips of honeycomb are removed in block or strip forms during cutting, and its structure and material removal method are obviously different from conventional machining. Existing simplified cutting force models based on kinematic analyses and experiments are incapable of describing the cutting process. In this paper, a geometrical kinematics analysis of SB is conducted. Further, the modelling of tool-workpiece contact rate (TWCR) for UC with SB is established, which is utilized to analyze the tool-material contact state. Based on the principle of conservation of energy, the fracture force at the blade edge is analyzed. Based on the analysis of instantaneous friction force, the friction force model on blade surfaces is established. Multiple-cutting experiments are conducted to separate fracture force and friction force. The influence of machining parameters (ultrasonic amplitude, lead angle, cutting speed) on TWCR, cutting force, fracture force, and friction force have been theoretically and experimentally studied, and the reduction mechanism of the cutting force is revealed. Furthermore, the machining quality under different machining parameters is observed and the relationship with cutting force is analyzed. The paper not only provides theoretical guidance for the study of the UC mechanism but also helps to guide the UC process of aramid honeycomb.

中文翻译：

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芳纶蜂窝超声切割中切削力降低机理

芳纶蜂窝在航空航天、轨道交通行业有着广泛的应用。直刀（SB）超声波切割（UC）是一种用于蜂窝材料轮廓加工的先进技术。切削力是影响加工质量的重要因素，其精确建模尤为重要。但SB是片状刀具，切削时以块状或条状形式去除蜂窝状切屑，其结构和材料去除方式与常规加工有明显不同。现有基于运动学分析和实验的简化切削力模型无法描述切削过程。本文对SB进行了几何运动学分析。此外，建立了UC与SB的刀具-工件接触率（TWCR）模型，用于分析刀具-材料接触状态。基于能量守恒原理，对刀刃处的断裂力进行了分析。在瞬时摩擦力分析的基础上，建立了叶片表面摩擦力模型。进行多次切削实验来分离断裂力和摩擦力。从理论上和实验上研究了加工参数（超声振幅、导程角、切削速度）对TWCR、切削力、断裂力和摩擦力的影响，揭示了切削力的降低机理。进一步观察不同加工参数下的加工质量并分析其与切削力的关系。该论文不仅为UC机理的研究提供了理论指导，也有助于指导芳纶蜂窝的UC工艺。