Mechanical research engineer in Fatigue Analysis of 304L Steel

Context :

EDF Research and Development and EDF Energy are currently developing their new centre: the EDF Energy R&D UK Centre. In addition, EDF R&D and the University of Manchester have created the Modelling and Simulation Centre in 2011. In the scope of the development of nuclear energy in the UK, EDF R&D and EDF Energy Generation wish to take advantage of this new centre in Manchester.

Topic :

The EDF Energy Generation team is currently working on the extension of the life expectancy of their nuclear power plants. One critical point is the integrity of the metallic components such as pipes, spine boilers … which are experiencing significant modifications with ageing. Also, the welding residual stress often exists in these components which may affect the component’s integrity and durability.

With regard to the fatigue crack initiation work, the main interest of Generation is elevated temperature (500-650°C) low cycle fatigue.  There currently are methods for the effect of multiaxial loading on fatigue crack nucleation and short crack growth, which are given in the R5 procedure.  These methods separate fatigue life into crack nucleation 0.02mm and short crack growth to the chosen initiation criterion of the engineers choice, say 1mm.  However, the limitations are proportional loading and R ratio of -1 only.  It would be interesting to improve the validation of these rules and to extend them to non-proportional loading and to include mean stress effects.

In a recent study conducted by EDF R&D, a new framework to correlate the experimental data of the 304L stainless steel under multi-axial fatigue loadings using a reference curve identified from the experimental data of standard uni-axial fatigue tests is proposed. Based on the limited available experimental fagtigue data and within the new framework in this paper, the computational results show that the equivalent crack initiation parameters of the Varvani-Farahani’s criterion, themodifiedLagoda-Macha-Sakane’s criterionand the modified Varvani-Farahani’s criterion can be used to correlate the experimental fatigue data under both uni-axial and bi-axial loadings for the 304L stainless steel under high temperature, non-proportional loading and with mean stress effects.

The scope of this 1-year VIE will be to apply the above identified criteria for the available experimental results at Generation and propose eventually the modifications so consistent initiation models can be identified for complex loads. Then, the consitent crack initiation criterion will be used to estimate the fatigue life of industrial components.

The VIE will work in the EDF Energy R&D UK Centre Low Carbon Generation team, and will be embedded in the Modelling and Simulation Centre. The candidate will benefit from the support of EDF Energy Generation and EDF R&D experts.

Location :

The VIE/Engineer will be based in the Modelling and Simulation Centre in Manchester. He/She will spend time with EDF Energy Generation in Barnwood and EDF R&D in France.

Duration:  1 year renewable.

Skills : Mechanical Engineer (Master degree).

Technical competences: solids and structure mechanics, fracture and fatigue mechanics, finite elements methods, programming, English.

Soft skills: desire for international exchanges, taste for team work, good oral and written communication skills.

Contact:  Dr. Van-Xuan Tran (van-xuan.tran@edfenergy.com)

Please note that European citizenship is required !