Understanding the fracture behavior of fused silica in contact sliding is important to the fabrication of damage-free optics. This study develops an analytical method to characterize the stress field in fused silica under contact sliding by extending the embedded center of dilation (ECD) model and considering the depth of yield region. The effects of densification on the stress fields were considered by scratch volume analysis and finite element analysis. Key mechanisms, such as crack initiation and morphology evolution were comprehensively investigated by analyzing the predicted stress fields and principal stress trajectories. The predictions were validated by Berkovich scratching experiment. It was found that partial conical, median and lateral cracks could emerge in the loading stage of the contact sliding, but radial and lateral cracks could be initiated during unloading. It was also found that the partial conical crack had the lowest initiation load. The intersection of long lateral cracks makes the material removal greater.

了解熔融石英在接触滑动中的断裂行为对于制造无损伤光学器件非常重要。本研究通过扩展嵌入式膨胀中心 (ECD) 模型并考虑屈服区深度，开发了一种表征接触滑动下熔融石英中应力场的分析方法。通过划痕体积分析和有限元分析考虑了致密化对应力场的影响。通过分析预测的应力场和主应力轨迹，全面研究了裂纹萌生和形态演化等关键机制。Berkovich 划痕实验验证了预测。结果发现，在接触滑动的加载阶段，会出现局部圆锥形、中部和侧向裂纹，但在卸载过程中可能会引发径向和横向裂纹。还发现部分锥形裂纹的起始载荷最低。长横向裂纹的交叉使材料去除量更大。