Establishment of the Off-Center Embedded Crack Stress Intensity Factor Database for Probabilistic Risk Assessment Based on Universal Weight Function

Probabilistic failure risk analysis is important in recent development of airworthiness. In the fracture mechanics module of probabilistic failure risk analysis, efficient and accurate stress intensity factor (SIF) solutions are vital. Universal weight function (UWF) is a method that has a remarkable computational efficiency and high accuracy in SIF calculation. However, the concrete coefficients in the UWF remain unknown, and the rules of the geometric parameters and these coefficients have not been clarified. This limitation hinders the subsequent application of the method. This article discusses general off-center embedded cracks. The response surface method (RSM), as a means of database establishment, is used to construct the relations between the coefficients in the UWF and geometric parameters. The mean absolute percentage errors of the SIFs between UWF and finite element method are less than 4% within a certain range. Gaussian process regression is adopted to better fit the data, especially when the crack is near the plate boundary and the R-square is over 0.96. In addition, the effect of the offset distance on SIFs is discussed for a certain embedded crack in a given plate. Results show that changes in the SIFs are dependent on the plate boundary in the uniform stress field. However, stress predominates the changes in the SIFs when the crack is not very close to the plate boundary in the nonuniform distributed stress fields. The databases and discussion that followed can provide some reference and inspiration for further research.