Tooth flank fracture (TFF) is a fatigue failure mode in gears in which the crack is initiated in a larger depth below the surface within the tooth volume. The crack propagates load-dependently and is not visually observable until final rupture of the tooth. The present publication focuses on numerical fatigue crack simulation of TFF in case-hardened spur gears. Herein, an existing phase-field model for fatigue fracture is revisited and extended to account for the simultaneous subsurface crack initiation and growth in high cycle fatigue during TFF. For this purpose, a gear tooth finite element model is implemented and parameterized using experimental data. Inhomogeneous material properties and residual stresses resulting from the manufacturing process are explicitly considered. The main interest of the study lies in the ability of the phase-field model to reproduce experimentally observable behavior during TFF such as subsurface crack initiation and the emerging subsurface crack path.

齿面断裂 (TFF) 是齿轮中的一种疲劳失效模式，其中裂纹在齿体积内表面下方的较大深度处开始。裂纹的扩展依赖于载荷，直到牙齿最终断裂时才能目视观察到。本出版物的重点是表面硬化直齿轮中 TFF 的数值疲劳裂纹模拟。在此，现有的疲劳断裂相场模型被重新审视和扩展，以解释 TFF 期间高周疲劳中同时发生的亚表面裂纹萌生和生长。为此，使用实验数据实施和参数化齿轮齿有限元模型。明确考虑了由制造过程产生的不均匀材料特性和残余应力。该研究的主要兴趣在于相场模型能够重现 TFF 期间的实验可观察行为，例如地下裂纹萌生和新出现的地下裂纹路径。