Measuring stress intensity factors durin

This paper investigates the application of thermoelastic stress analysis (TSA) in measuring stress intensity factors during fatigue crack growth in welded ferritic steel plates. The primary objective was to assess the sensitivity of the TSA technique to crack closure effects and residual stresses resulting from welding. Through a series of fatigue crack growth tests, the research aimed to establish a direct method for analyzing crack tip stresses under cyclic loading. The methodology involved using TSA to acquire full-field stress maps from the surface of the welded components subjected to cyclic loads. The results demonstrated that stress intensity factors derived from the thermoelastic experiments are directly obtained from the cyclic stress field ahead of the fatigue crack, rather than being inferred from crack length and load range measurements. The findings indicate that the technique effectively captures the complexities associated with the crack growth behavior, emphasizing its applicability in providing critical insights into the mechanisms influencing fatigue failures in welded structures. This work contributes to enhancing the understanding of fatigue crack propagation and the role of residual stresses in structural integrity assessments.