The interface fracture toughness of SnSb11Cu6/20steel was measured by calculating the critical energy release rate and stress phase angle of the interface crack. A three-point bending test was used to introduce cracks into the bonding interface, and the cohesion model of the bonding interface was established through experimental data. Through finite element analysis of load-deflection curves with and without interface crack propagation, the crack initiation point is found. Then the energy calculation model of crack propagation is established, and the critical energy release rate is obtained using the virtual crack growth criterion. The calculation results of the stress phase angle show that the crack propagation is greatly affected by the normal stress after the babbitt alloy layer fractures. If the strength of the substrate material is weaker, the crack will continue to expand in the tangent perpendicular to the crack tip.

中文翻译：

---

焊接巴氏合金SnSb11Cu6/20Steel的界面断裂韧性测量

通过计算界面裂纹的临界能量释放速率和应力相角来测量SnSb11Cu6/20钢的界面断裂韧性。采用三点弯曲试验将裂纹引入键合界面，通过实验数据建立了键合界面的内聚力模型。通过对有界面裂纹扩展和无界面裂纹扩展的载荷-挠度曲线进行有限元分析，找到了裂纹萌生点。然后建立裂纹扩展能量计算模型，利用虚拟裂纹扩展准则得到临界能量释放率。应力相角计算结果表明，巴氏合金层断裂后，裂纹扩展受法向应力影响较大。如果基材的强度较弱，