Abstract

ABSTRACT
Residual stresses, those that persist within materials devoid of external influences, play a pivotal role in dictating the fatigue life of mechanical structures. These stresses, emerging predominantly from material deformation heterogeneities, often have profound implications for the performance and longevity of components, especially in industries such as boiler-making and pressure vessels. Welding, an assembly process extensively utilized in these sectors, induces thermomechanical constraints at the joint, a consequence of the techniques and temperatures involved. The crux of evaluating residual stresses lies in its potential to forecast admissible stress levels during the design phase, allowing for optimized structure sizing and the assessment of specialized stress treatments\' efficacy.
This research stems from an established theme within our team, focusing on the intricate study of pre-cracked mechanical structures, specifically emphasizing stainless steel subjected to complex stresses. The overarching objective of the research is encapsulated in its theme: \"Forecast/evaluation reliable performance of structural mechanical systems and optimal mechanical design.\" Through an in-depth exploration of welding dynamics and the resulting residual stresses, the study offers insights into the nuanced interplay between welding techniques, material properties, and subsequent structural behavior. The findings are instrumental in providing guidelines for enhanced design strategies, paving the way for more resilient and efficient welded structures in practical applications.
This extensive study thoroughly examines the intricacies involved in welding operations, with a specific emphasis on butt joints in austenitic pipes. Utilizing FEA, the study illuminated the impact of welding sequences on residual stresses and associated distortions. Emphasis was placed on the potential of multi-pass welding in enhancing joint strength and producing microstructures with reduced residual stresses. The research also explored innovative stress mitigation techniques, namely the IHSI and MSIP, underscoring their efficacy in combating stress-related vulnerabilities in welded structures.

Keywords: Probabilistic fracture mechanics; Residual stresses; Structural reliability; Intergranular stress corrosion cracking; Mitigation techniques; Finite element analysis.

Information

Item Type:	Thesis
Divisions:	» Faculty of Science and Technology
ePrint ID:	4887
Date Deposited:	2024-02-26
Further Information:	Google Scholar
URI:	https://www.univ-soukahras.dz/en/publication/article/4887

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