Two-dimensional ultrasonic-assisted grinding (2D-UAG) is a highly efficient process for brittle materials. Compared to conventional grinding (CG) and one-dimensional ultrasonic-assisted grinding (1D-UAG), the surface quality of workpieces can be further improved. Unidirectional carbon-fiber-reinforced silicon carbide composites (UD-Cf/SiCs) have a wide range of applications in engineering. However, the existing mechanical models developed for the machining of Cf/SiCs have various limitations, especially the inability to reflect the transient force information. In this work, a dynamic force prediction model is developed for the 2D-UAG of the Cf/SiCs. In the modelling process, the micro-morphology of the grinding wheel was first characterized. Secondly, the cutting force of a single grit was obtained based on the fiber fracture theory and the energy conservation law. Finally, considering the grain movement in the 2D-UAG, a novel force decomposition and synthesis algorithm was used to calculate the total force. The validation results showed that the maximum predicted error of the model for the resultant force Fs is 14.86 % and the average value is 7.36 %. The predicted boundary values and mean values of the fractional forces Fn and Ft are also in good agreement with the experimental values. In addition, the fibers have a large influence on the fluctuation of the force value due to the suppression of transverse crack extension. The order of influence is Perpendicular > Transverse > Longitudinal.

中文翻译：

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单向 Cf/SiC 复合材料二维超声辅助磨削的力学模型

二维超声波辅助磨削 （2D-UAG） 是一种处理脆性材料的高效工艺。与传统磨削 （CG） 和一维超声波辅助磨削 （1D-UAG） 相比，工件的表面质量可以进一步提高。单向碳纤维增强碳化硅复合材料 （UD-Cf/SiC） 在工程中具有广泛的应用。然而，为加工 Cf/SiC 而开发的现有机械模型存在各种局限性，尤其是无法反映瞬态力信息。在这项工作中，为 Cf/SiCs 的 2D-UAG 开发了一种动态力预测模型。在建模过程中，首先表征了砂轮的微观形貌。其次，基于纤维断裂理论和能量守恒定律得到单粒砂砾的切削力;最后，考虑到 2D-UAG 中的晶粒运动，使用一种新的力分解和合成算法来计算总力。验证结果表明，模型对合力 Fs 的最大预测误差为 14.86 %，平均值为 7.36 %。分数力 Fn 和 Ft 的预测边界值和平均值也与实验值非常吻合。此外，由于抑制了横向裂纹扩展，纤维对力值的波动有很大影响。影响顺序为垂直>横向>纵向。