Browsing Mechanical Engineering by Author "Barrett, Richard A."
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Cyclic plasticity of welded P91 material for simple and complex power plant connections
Li, Ming; Barrett, Richard A.; Scully, Stephen; Harrison, Noel M.; Leen, Sean B.; O’Donoghue, Padraic E. (Elsevier, 2016-02-10)This paper focuses on with the cyclic plasticity modelling of welded, ex-service P91 material. A multi material model is developed for high temperature cyclic plasticity, including the effects of the three different material ... -
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. ... -
A dislocation-based model for high temperature cyclic viscoplasticity of 9-12Cr steels
Barrett, Richard A.; O'Donoghue, Peter E.; Leen, Sean B. (Elsevier ScienceDirect, 2015-06-22)A dislocation-based model for high temperature cyclic viscoplasticity in 9–12Cr steels is presented. This model incorporates (i) cyclic softening via decrease in overall dislocation density, loss of low angle boundary ... -
A dislocation-based yield strength determination model in nano-indentation test
Tao, Ping; Ye, Fei; Gong, Jianming; Barrett, Richard A.; Leen, Sean B. (SAGE Publications, 2021-02-20)This paper presents a dislocation-based yield strength model for the nano-indentation size effect. The model is based on functional expressions involving the densities of statistically stored dislocations and geometrically ... -
Dual-phase cohesive zone modelling and experimental validation for hydrogen-assisted cracking of 2205 duplex stainless steel
Tao, Ping; Ye, Fei; Gong, Jianming; Yang, Xinyu; Barrett, Richard A.; Leen, Sean B. (Elsevier, 2021-01-01)The hydrogen-assisted cracking (HAC) behavior of 2205 duplex stainless steel is investigated via experimental testing and computational modelling, with specific focus on developing a predictive methodology for the coupled ... -
Effect of high-temperature corrosion on the service life of P91 piping in biomass co-firing
O'Hagan, C.; Barrett, Richard A.; Leen, Sean B.; Monaghan, Rory F.D. (American Society of Mechanical Engineers (ASME), 2016-02-24)Co-firing biomass with traditional fuels is becoming increasingly relevant to thermal power plant operators due to increasingly stringent regulations on greenhouse gas emissions. It has been found that when biomass is ... -
Experimental and computational characterization of the effect of manufacturing-induced defects on high temperature, low-cycle fatigue for MarBN
O'Hara, Eimear M.; Phelan, B.; Osgerby, S.; Barrett, Richard A.; Raghavendra, R.; Leen, Sean B.; Harrison, Noel M. (Elsevier, 2020-05-22)Manufacturing-induced defects are a key source of crack initiation and component failure under high temperature cyclic loading. In this work, 3D X-ray micro-computed tomography and microstructural analysis of manufacturing-induced ... -
Fatigue damage characterisation of MarBN steel for high temperature flexible operating conditions
O'Hara, Eimear M.; Harrison, Noel M.; Polomski, B. K.; Barrett, Richard A.; Leen, Sean B. (SAGE Publications, 2016-09-10)This article is concerned with the high temperature low cycle fatigue behaviour of a new nano-strengthened martensiticferritic steel, MarBN. A range of strain-controlled, low cycle fatigue tests are presented on MarBN at ... -
Finite element modelling for mitigation of residual stress and distortion in macro-scale powder bed fusion components
Zhou, Jinbiao; Barrett, Richard A.; Leen, Sean B. (SAGE Publications, 2022-12-23)Powder bed fusion (PBF) has attracted significant attention in many applications due to its capability of fabricating complex and customized metal parts. However, the potential for high inherent residual stresses that ... -
An improved unified viscoplastic model for strain-rate sensitivity in high temperature fatigue
Barrett, Richard A.; O'Donoghue, P. E.; Leen, Sean B. (Elsevier ScienceDirect, 2013-11-21)An improved unified cyclic viscoplastic material model for high temperature fatigue of P91 steel is presented. The primary enhancement over existing models is in relation to strain-rate independence of parameters, for ... -
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. ... -
A multi-axial cyclic viscoplasticity model for high temperature fatigue of P91 steel
Barrett, Richard A.; Leen, Sean B. (Maney Online, 2014)This paper presents a novel multiaxial, cyclic viscoplasticity material model for high temperature low cycle fatigue of P91 power plant steel. The model incorporates mechanisms-based variable strain-rate sensitivity and ... -
A multi-scale crystal plasticity model for cyclic plasticity and low-cycle fatigue in a precipitate-strengthened steel at elevated temperature
Li, Dong-Feng; Barrett, Richard A.; O'Donoghue, Padraic E.; O'Dowd, Noel P.; Leen, Sean B. (Elsevier, 2016-12-24)In this paper, a multi-scale crystal plasticity model is presented for cyclic plasticity and low-cycle fatigue in a tempered martensite ferritic steel at elevated temperature. The model explicitly represents the geometry ... -
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 creep damage model for effects of different precipitate types
Ó. Murchú, C.; Leen, Sean B.; O'Donoghue, Padraic; Barrett, Richard A. (Elsevier, 2016-10-13)The development of a new precipitate coarsening continuum damage mechanics (CDM) model to simulate the multi-precipitate strengthening mechanisms present in 9Cr steels under high temperature creep deformation is presented ... -
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 physically-based method for predicting high temperature fatigue crack initiation in P91 welded steel
Zhou, Jinbiao; Barrett, Richard A.; Leen, Sean B. (Elsevier, 2021-08-27)A methodology is presented for physically-based prediction of high temperature fatigue crack initiation in 9Cr steels, with a focus on material inhomogeneity due to welding-induced metallurgical transformations. A modified ... -
Prediction of microstructure evolution for additive manufacturing of Ti-6Al-4V
Yang, Xinyu; Barrett, Richard A.; Tong, Mingming; Harrison, Noel M.; Leen, Sean B. (Elsevier, 2020-04-26)A key challenge for successful exploitation of additive manufacturing (AM) across a broad range of industries is the development of fundamental understanding of the relationships between process control and mechanical ... -
Predictions of ICHAZ cyclic thermo-mechanical response in GTAW process for 9Cr steels
Mac Ardghail, Padraig; Barrett, Richard A.; Harrison, Noel M.; Leen, Sean B. (ASME The American Society of Mechanical Engineers, 2019-02-25)This work is concerned with the development of a modeling framework to predict the effects of tempered–untempered martensite heterogeneity on the thermomechanical performance of welded material. A physically based ...