PSI - Issue 70

Varsha S et al. / Procedia Structural Integrity 70 (2025) 51–58

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Fig. 4. Tearing Mode (K3) plotted SIF vs. crack growth length (mm )

Furthermore, The applied cracking force makes the crack surfaces slide toward perpendicular directions relative to the crack plane as shown in Fig. 3. Mode III loading represents the condition where anti-plane shear stress develops on the surfaces of cracks. A total comprehension of material fracture behavior emerges through the analysis of all three crack propagation modes. These loading modes show significance in combined conditions because they trigger multiple failure mechanisms. Stress Intensity Factors deliver essential information about how structural steel plates break. Highly accurate determination of SIFs requires dense mesh resolutions but it results in increased computational requirements. The maximum values of Stress Intensity Factors appear inside the center section of semi-elliptical cracks. Bringing together semi-elliptical and semi-circular crack analyses produces knowledge regarding the best crack formations when operating under specific stress conditions. A complete structural assessment needs to evaluate cracks across both its in-plane and out-of-plane fissure directions. Structural integrity assessments become more effective through the consistently increasing SIF metrics which span from short to long crack dimensions. The fracture mode tests produced results which are represented in Fig. 1 through 3. 4. Conclusion The research introduces a method to determine the Stress Intensity Factor (SIF) values in clamped rectangular steel plates which have semi-circular and semi-elliptical surface cracks under both Mode I, II, and III loading conditions. Error-free results demonstrate that SIF values are heavily influenced by both the shape of the crack and its depth distribution when Point Load Weight Function Method analysis is validated through FEM simulation. The numerical value of SIFs reaches its highest peak at the center region of semi-elliptical cracks which amounts to 25% greater than semi-circular cracks and surface regions show opposing trends. The structural assessment requires precise consideration of crack depth because SIF values demonstrate significant growth throughout increasing values of a/d. This evaluation method stands as an efficient computational solution that provides accurate fracture assessment when compared to conventional full-field FEM analysis during initial stages. Engineering teams can use the obtained results to forecast material failure types which enables enhancements in resistance to damage across bridge structures and pressurized systems as well as aircraft frames. The proposed method requires further development which should encompass multiple materials and sophisticated geometries and also three-dimensional loading scenarios to achieve comprehensive application. References Ghajar, R., & Saeidi Googarchin, H. 2013. General point load weight function for semi-elliptical crack in finite thickness plates. Engineering Fracture Mechanics, 109, 33–44. doi:10.1016/j.engfracmech.2013.06 Ghajar, R., & Kaklar, J. A. 2015 Mixed mode weight functions for an elliptical subsurface crack under shear loadings. Engineering Fracture Mechanics, 136, 58–75. doi:10.1016/j.engfracmech.2015.01 Alizadeh K., J., & Ghajar, R. 2014. Calculation of mixed mode stress intensity factors for an elliptical subsurface crack under arbitrary normal loading. Fatigue & Fracture of Engineering Materials & Structures, 38(6), 700–713. doi:10.1111/ffe.12271 Wang, X., & Glinka, G. 2009. Determination of approximate point load weight functions for embedded elliptical cracks. International Journal of Fatigue, 31(11-12), 1816–1827. doi:10.1016/j.ijfatigue.2008.12.002 Jin, M., Nandy, R., Curran, T., & Cordes, D. 2012. Extending Local Canonical Correlation Analysis to Handle General Linear Contrasts for fMRI Data. International Journal of Biomedical Imaging, 2012, 1–14. doi:10.1155/2012/574971