Issue 71

M. Abdulla et alii, Fracture and Structural Integrity, 71 (2025) 124-150; DOI: 10.3221/IGF-ESIS.71.10

values. Understanding this intricate relationship is crucial for assessing the structural response under varying thermal conditions, providing valuable insights for materials and design considerations in real-world applications. This detailed analysis highlights the critical influence of negative temperature variations on the structural integrity of the repaired plate, showing how thermal contraction exacerbates stress concentrations at the crack tip and leads to higher SIF values as can be seen in Fig. 16.

Figure 16: SIF under negative temperature.

Patch thickness In a comprehensive analysis encompassing both thermo-mechanical and mechanical loading scenarios, a striking disparity in the behaviour of SIF concerning patch thickness was observed. Under thermo-mechanical loading conditions, it became evident that an increase in patch thickness directly correlated with an escalation in SIF at the crack tip. At a relatively modest temperature of 30 ℃ , the SIF values exhibited minimal disparity among various patch thicknesses, denoting only marginal increments. However, as the temperature was elevated to 110 ℃ , a more pronounced discrepancy in SIF values emerged when comparing different patch thicknesses to the configuration with the least thickness of 0.5 mm increased to 0.75 mm, then to 1 mm and the highest thickness of 1.25 mm, resulting in SIF increments of 18%, 36%, and 53% as shown in Fig. 17 respectively.

Figure 17: SIF for different patch thicknesses under thermo-mechanical loading.

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