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Feng, W. (author)Steel jacket support structures for offshore wind turbine towers made of circular hollow sections (CHS) are becoming a competitive solution compared to monopiles in deeper waters. The current limitation to improving the durability and cost-effectiveness of the CHS structures is the low fatigue endurance of their welded joints. Fatigue-driven...doctoral thesis 2024
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Aghaeian, S. (author)H igh-temperature (HT) oxidation plays a significant role in various stages of the steelmaking process, including hot rolling. When exposed to high temperatures and oxygen partial pressure, the steel composition near the surface can be altered as alloying elements deplete. Additionally, the characteristics of the oxide scale, such as thickness...doctoral thesis 2024
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Jiang, Quanxin (author)The need for more accurate cleavage modelling is particularly acute for a new generation of high-strength steels because they obtain their favourable properties through complex, multi-phase microstructures. One of the challenges in cleavage modelling is the strong sensitivity to material characteristics at the microlevel. This thesis proposes a...doctoral thesis 2023
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Morete Barbosa Bertolo, V. (author)The use of materials in increasingly severe service conditions raises concerns about structural safety with respect to cleavage fracture. There are three main material-related challenges that structures face under harsh environments: 1) the trade-off between strength and toughness; 2) the ductile-to-brittle transition behaviour of BCC high...doctoral thesis 2023
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Atreya, V. (author)Dual-phase (DP) steels are an important class of advanced high-strength steels (AHSS) and constitute a major share of steels for the automotive industry. A microstructure consisting of hard martensite embedded in a soft ferritic matrix gives them a good combination of strength and ductility. The martensite formation in the microstructure from...doctoral thesis 2023
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Yan, R. (author)High-strength steel (HSS) has higher strength but lower ductility than mild steel. The cross-section of the structural members may be reduced using HSS instead of mild steel, provided the buckling of elements does not govern the failure. The reduced member size benefits the environment and economy by means of less energy consumption, less carbon...doctoral thesis 2023
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Marques Pereira, V. (author)An approach to improve the performance of steels for fusion and fission reactors is to reinforce them with oxide nanoparticles. These can hinder dislocation and grain boundary movement and trap radiation-induced defects, thus increasing creep and radiation damage resistance. Steels containing these oxide particles are called ODS steels (Oxide...doctoral thesis 2022
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Ioannidou, C. (author)The focus of the present work is on the micro-alloying element vanadium, which is well known for providing precipitation strengthening to steels and which has, therefore, attracted a lot of interest the last decades. Vanadium carbide precipitation can take place in the migrating austenite/ferrite interface during the austenite-to-ferrite phase...doctoral thesis 2022
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Fu, J. (author)Oxide dispersion strengthened (ODS) steels are promising candidates for use as structural materials in the next generation fission and fusion reactors. Compared to conventional ferritic or martensitic steels, ODS steels exhibit improved high-temperature creep properties and irradiation resistance. Favourable properties are mainly attributed to...doctoral thesis 2021
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Hajizad, O. (author)In this PhD thesis, we investigated possible steel candidates for use in railway crossings in order to reduce the damage in them. Pearlitic R350HT together with Bainitic grades including CrB, B1400 and carbide free B360 were investigated for their mechanical properties such as ultimate strength, yield strength, ductility and hardness. The...doctoral thesis 2021
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Nijgh, M.P. (author)Traditionally welded headed studs have been used to generate composite interaction between a steel beam and a (cast in-situ) concrete floor. This permanent connection impairs the demountability of the structural components and therefore demolition of the composite floor system is inevitable at the end of the functional service life. The...doctoral thesis 2021
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Chen, Zhipei (author)Currents flowing along paths not being elements of a purpose-built electric circuit, are called stray currents. Various types of reinforced concrete structures (such as viaducts, bridges and tunnels) in the neighborhoods of railways may be subjected to stray current leaking from the rails. In these cases the concrete pore solution acts as an...doctoral thesis 2021
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Nguyen-Minh, T. (author)Texture and anisotropy are persistent characteristics of polycrystal. Because of the ordered and periodic arrangement of atoms in crystal lattices, responses of each oriented crystals in a polycrystal to the same external forces are not similar. Crystal grains which are better accommodated to boundary conditions because of their energetically...doctoral thesis 2021
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Meeusen, M. (author)The corrosion protection of metallic substrates with corrosion inhibitors, either in solution or dispersed in a coating formulation, has been the focus of many research topics for many decades and has intensified in recent years even more with industry moving away from hexavalent chromium (Cr(VI))- based corrosion inhibitors. While mainly...doctoral thesis 2020
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van Lieshout, P.S. (author)Structural geometry and stochastic loads such as swell and wind seas can typically induce multiaxial stress states in welded details of marine structures. It is known that such complex time varying stress states determine the fatigue resistance of welded steel joints. Therefore, it is of importance to account for them in fatigue lifetime...doctoral thesis 2020
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Yu, H. (author)The development in computational simulation techniques has brought significant progress in the realization of computational alloy design. The advantages are most significant when developing novel materials of which the research & development cycles are particularly time and energy (and hence cost) consuming, such as high-temperature alloys....doctoral thesis 2019
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Ravi, A.M. (author)The formation of bainite in steels is one of the most intensely researched topics in the field of metallurgy. Despite the importance of bainite among the modern-day steels, even a qualitative theory to explain the bainite formation still remains a subject of controversy due to the complexity of its formation mechanism. Currently, two competing...doctoral thesis 2019
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Eftekharimilani, P. (author)The potential for weight reduction, ease of manufacturing and improved crashworthiness makes advanced and ultra high strength steels attractive for automotive applications. Resistance spot welding is by far the most widely used joining method in the automotive industry due to the high operating speeds, the reliability of the process and the...doctoral thesis 2019
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Shakerifard, B. (author)Global warming, continuous demand on energy from fossil fuels as a limited natural resource, and costumers’ high expectations regarding product quality are three global challenges that the automotive industry is facing. Fuel consumption reduction has a significant impact on preserving fossil fuels, lowering fossil fuel dependency and the CO2...doctoral thesis 2019
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Agarwal, G. (author)Preventing solidification cracking is an essential prerequisite for the safety of a welded structure. An undetected solidification crack has the potential to cause premature failure during service. Two conditions generated by a weld thermal cycle are responsible for the initiation of solidification cracks. The first is the presence of excessive...doctoral thesis 2019