الفهرس 
The effect of residual stress on fatigue crack growth rateOnly 14 pages are availabe for public view
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Abstract
Fracture assessment is a convenient technique that focuses on characterizing fracture processes, as well as it provides practical assessing and testing techniques for material defect control. The presence of defects causes a variation in fracture mechanics when compared with the strength of the material field, which starts with the assumption that the material is free of imperfections. The basic characteristics of fracture mechanics are that it accepts the presence of cracks, examines the crack propagation rate specifically due to fatigue load, and calculates the remaining life of structural elements in a safe state. In this context, comprehensive numerical analyses employing fracture mechanics concepts were provided to propose a description of the fracture evaluation for thin butt-welded 304 L stainless joints. The major objective of this research is to study the effect of welding residual stress and crack orientation on fracture parameters, and also, the influences of welding residual stress on the fatigue crack propagation. This study presents two types of analysis; sequentially thermomechanical analysis to investigate welding residual stress and extended finite element analysis (XFEM) to model the propagation of fatigue cracks. In the beginning, longitudinal and transverse cracks in the direction of the welding line were modeled as stationary cracks using XFEM to investigate the effects of crack orientation on effective stress intensity factor (k_eff) in the presence and absence of welding residual stress and the results were validated analytically. Since welded joints are susceptible to fatigue failure due to cyclic loading, as well as fatigue crack propagation affected by welding residual stress distribution, a transverse crack was modeled using XFEM to predict fatigue crack growth, and examine the impact of welding residual stress on it. To verify the simulation results, the crack growth model (NASGRO) and accessible experimental data were used. In addition, the research examined how to evaluate fracture toughness in thin plates using the essential work of fracture (EWF) technique, which was used both experimentally and numerically.