Browsing by Author "O'Donoghue, Padraic E."
Now showing items 1-11 of 11
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A dislocation mechanics constitutive model for effects of welding-induced microstructural transformation on cyclic plasticity and low-cycle fatigue for X100Q bainitic steel
Devaney, Ronan J.; Barrett, Richard A.; O'Donoghue, Padraic E.; Leen, Sean B. (Elsevier, 2020-12-14)This paper presents a physically-based cyclic viscoplasticity model to capture the influence of welding-induced microstructural transformation on the fatigue response of the bainitic high-strength low-alloy steel, X100Q. ... -
Effect of welding on microstructure and mechanical response of X100Q bainitic steel through nanoindentation, tensile, cyclic plasticity and fatigue characterisation
Devaney, Ronan J.; O'Donoghue, Padraic E.; Leen, Sean B. (Elsevier, 2020-12-30)This paper presents an experimental characterisation of fatigue at welded connections for the next-generation high-strength low-alloy offshore riser steel, X100Q. An instrumented girth weld is conducted with a parallel ... -
Experimental characterisation and computational constitutive modelling of high temperature degradation in 9Cr steels including microstructural effects
Barrett, Richard A. (2016-04-20)The transition from base-load to intermittent power plant operation has led to the requirement for increased knowledge and more accurate prediction of the effects of flexible loading on plant components. This thesis is ... -
Experimental characterisation and computational modelling for cyclic elastic-plastic constitutive behaviour and fatigue damage of X100Q for steel catenary risers
Devaney, Ronan J.; O'Donoghue, Padraic E.; Leen, Sean B. (Elsevier, 2018-06-21)New higher strength steels are required for deep and ultra-deepwater steel catenary risers (SCRs). In this work, the cyclic elastic-plastic-damage behaviour of X100Q, a candidate next-generation SCR material is experimentally ... -
Global and local fatigue analysis of X100 and X60 steel catenary riser girth welds
Devaney, Ronan J.; O'Donoghue, Padraic E.; Leen, Sean B. (Taylor & Francis, 2017-08-31)The use of steel catenary risers in offshore oil and gas production has increased significantly in recent years, in particular for deepwater applications. This paper presents a detailed assessment approach with respect to ... -
Influence of material inhomogeneity on the mechanical response of a tempered martensite steel
Li, Ming; Sun, F. W.; Barrett, Richard A.; Meade, E.; Li, D. F.; O'Donoghue, Padraic E.; Leen, Sean B.; O'Dowd, Noel P. (SAGE Publications, 2017-01-13)Failure in steel weldments operating at high temperatures often occurs in the heat-affected zone adjacent to the weld. Such failures can be a result of material inhomogeneity within the heat-affected zone and in the case ... -
Micromechanical finite element modelling of thermo-mechanical fatigue for P91 steels,
Li, Dong-Feng; Barrett, Richard A.; Leen, Sean B.; O'Donoghue, Padraic E. (Elsevier, 2016-01-21)In this paper, the cyclic plasticity and fatigue crack initiation behaviour of a tempered martensitic ferritic steel under thermo-mechanical fatigue conditions is examined by means of micromechanical finite element modelling. ... -
Microstructure modeling of high-temperature microcrack initiation and evolution in a welded 9Cr martensitic steel
Li, Ming; O'Donoghue, Padraic E.; Leen, Sean B. (SAGE Publications, 2019-02-28)Welded joints in tempered 9Cr-1Mo operating at elevated temperatures are well known to be prone to premature failure due to cracking in the heat-affected zone. This paper describes a crystal plasticity model to predict the ... -
A physically-based constitutive model for high temperature microstructural degradation under cyclic deformation
Barrett, Richard A.; O'Donoghue, Padraic E.; Leen, Sean B. (Elsevier, 2017-03-23)This paper presents a dislocation-mechanics cyclic viscoplasticity model which incorporates the key physical micro-mechanisms of strengthening and softening for high temperature deformation of 9Cr steels. In particular, ... -
A physically-based high temperature yield strength model for 9Cr steels
Barrett, Richard A.; O'Donoghue, Padraic E.; Leen, Sean B. (Elsevier, 2018-05-24)The strength of 9Cr steels, which is controlled by chemical composition and microstructure, evolves significantly under high temperature loading. This paper presents a temperature-independent, physically-based model for ... -
A review of the integrity of metallic vehicle armour to projectile attack
Lenihan, Donncha; Ronan, William; O'Donoghue, Padraic E.; Leen, Sean B. (SAGE Publications, 2018-02-28)This article presents a review of engineering and design aspects relevant to the mechanical and structural integrity of military vehicular armour, including materials-related technologies. Theoretical, experimental and ...