为了进一步揭示超声振动辅助磨削加工机理，建立了超声振动辅助磨削亚表面损伤深度与断裂韧性的预测模型，设计几何形状随机的单颗磨粒超声振动压痕实验和超声振动辅助磨削实验，调查两种情况下K9光学玻璃压痕变形区域形貌特征，提出一种适用于超声振动和非超声振动两种加载条件的等效断裂韧性计算方法，并通过超声振动辅助磨削实验来验证预测模型的可靠性。实验结果表明，超声振动可以有效增加K9光学玻璃抵抗断裂的能力，降低亚表面损伤程度，且预测模型与实验结果具有良好的一致性。

In order to further reveal the mechanism of ultrasonic vibration assisted grinding, a prediction model of the ultrasonic vibration assisted grinding subsurface damage depth and fracture toughness was established. The single random-shape diamond grit indentation experiments without ultrasonic vibration and ultrasonic vibration assisted grinding experiments were designed. The indentation features of K9 optical glass in the two cases were investigated. A calculation method of equivalent fracture toughness suitable for two cases was proposed. The reliability of the model is verified by ultrasonic vibration assisted grinding experiments. The experimental results show that ultrasonic vibration can effectively increase the resistance of K9 optical glass to fracture, and the prediction model has a good consistency with the test results.