Browsing Mechanical Engineering by Author "Leen, Sean B."
Now showing items 1-20 of 91
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A CFD investigation of a variable-pitch vertical axis hydrokinetic turbine with incorporated flow acceleration
Mannion, Brian; McCormack, Vincent; Leen, Sean B.; Nash, Stephen (Springer, 2019-02-18)This paper presents the numerical modelling of a novel vertical axis tidal turbine that incorporates localised flow acceleration and variable-pitch blades. The focus is to develop a computational fluid dynamics model of a ... -
Characterisation of LCF performance of X100 weld-joints: Mechanistic yield strength modelling, finite element analyses and DIC testing
Long, D.J.; Devaney, R.J.; O'Donoghue, P.E.; Song, H.; Barrett, R.A.; Leen, Sean B. (Elsevier, 2021-03-26)This paper is concerned with the effect of welding on the fatigue behaviour of X100 material for steel catenary risers. The methodology includes both modelling and experimental characterisation. The modelling combines (i) ... -
A combined wear-fatigue design methodology for fretting in the pressure armour layer of flexible marine risers
O'Halloran, S.M.; Shipway, P.H.; Connaire, A.; Leen, Sean B.; Harte, Annette M. (Elsevier, 2016-10-20)This paper presents a combined experimental and computational methodology for fretting wear-fatigue prediction of pressure armour wire in flexible marine risers. Fretting wear, friction and fatigue parameters of pressure ... -
A combined wear-fatigue design methodology for fretting in the pressure armour layer of flexible marine risers
O'Halloran, Sinéad M.; Shipway, Philip H.; Connaire, Adrian D.; Leen, Sean B.; Harte, Annette M. (Elsevier, 2016-10-20)This paper presents a combined experimental and computational methodology for fretting wear-fatigue prediction of pressure armour wire in flexible marine risers. Fretting wear, friction and fatigue parameters of pressure ... -
A comparison of two quasi-static computational models for assessment of intra-myocardial injection as a therapeutic strategy for heart failure
Fan, Yiling; Ronan, William; Teh, Irvin; Schneider, Jurgen E.; Varela, Claudia E.; Whyte, William; McHugh, Peter; Leen, Sean B.; Roche, Ellen (Wiley, 2019-05-06)Myocardial infarction, or heart attack, is the leading cause of mortality globally. Although the treatment of myocardial infarct has improved significantly, scar tissue that persists can often lead to increased stress and ... -
Computational simulation of the relaxation of local stresses due to foreign object damage under cyclic loading
Leen, Sean B. (2010)In this study, the phenomenon of residual stress relaxation from foreign object damage (FOD) is numerically simulated using a hybrid explicit¿implicit finite-element method. The effects of cycle fatigue loadings on stress ... -
A critical analysis of plastic flow behaviour in axisymmetric isothermal and Gleeble compression testing
Bennett, CJ,Leen, SB,Williams, EJ,Shipway, PH,Hyde, TH; Leen, Sean B. (Elsevier ScienceDirect, 2010-08-16)Coupled thermo-mechanical finite element modelling of both isothermal axisymmetric compression and compression testing using the Gleeble thermo-mechanical simulator has been carried out in order to compare the levels of ... -
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 ... -
Cyclic thermo-mechanical material modelling and testing of 316 stainless steel
Leen, Sean B. (Elsevier ScienceDirect, 2010-04-20)A programme of cyclic mechanical testing of a 316 stainless steel, at temperatures of up to 600 C under isothermal conditions, for the identification of material constitutive constants, has been carried out using a ... -
Cyclic viscoplasticity testing and modelling of a service-aged P91 steel
Farragher, Tadhg P.; Leen, Sean B. (American Society of Mechanical Engineers, 2014-04-16)A service-aged P91 steel was used to perform an experimental program of cyclic mechanical testing in the temperature range of 400 °C–600 °C, under isothermal conditions, using both saw-tooth and dwell (inclusion of a ... -
Damage and permeability in tape-laid theromplastic composite cryogenic tanks.
Grogan, David M.; Ó Brádaigh, Conchúr M.; McGarry, J. P.; Leen, Sean B. (2015-09-07) -
Damage characterisation of cryogenically cycled carbon fibre/PEEK laminates
Grogan, David M.; Leen, Sean B.; Ó Brádaigh, Conchúr M. (Elsevier ScienceDirect, 2014-08-14)A unique insight into damage formation in CF/PEEK laminates before, during and after cryogenic cycling, using optical microscopy and 3D X-ray computed tomography (CT), is presented. Thicker laminates were found to exhibit ... -
Deformation mechanisms of selective laser melted 316L austenitic stainless steel in high temperature low cycle fatigue
Chen, Yefeng; Wang, Xiaowei; Shen, Jiawei; Peng, Yawei; Jiang, Yong; Yang, Xinyu; Leen, Sean B.; Gong, Jianming (Elsevier, 2022-04-22)To investigate the low cycle fatigue (LCF) properties of SLM (Selective laser melting) 316L at 550 °C high temperature, a series of LCF tests at different strain amplitudes is conducted on SLM 316L and traditional 316L. ... -
Design of composite tidal turbine blades
Grogan, David M.; Leen, Sean B.; Kennedy, Ciaran; Ó Brádaigh, Conchúr M. (2013-02-24)Tidal turbine blades are subjected to significant thrust and torsional loadings due to the high density ofthe seawater in which they operate. These thrust loadings lead to high bending moments at the bladeroot, which can ... -
Development and assessment of a blade element momentum theory model for high solidity vertical axis tidal turbines
Mannion, Brian; Leen, Sean B.; Nash, Stephen (Elsevier, 2020-01-20)Tidal energy is an attractive renewable resource given its predictability. The production of reliable, efficient and cost-effective tidal energy turbines requires the development of computer models for assessment and design ... -
Development of life assessment procedures for power plant headers operated under flexible loading scenarios
Farragher, Tadhg P.; Leen, Sean B. (Elsevier ScienceDirect, 2013-12-22)A finite element methodology for thermo-mechanical fatigue analysis of a subcritical power plant outlet header under realistic loading conditions is presented. The methodology consists of (i) a transient heat transfer ... -
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 ...