Education

• 2008-2011: Ph.D in Mechanical Engineering
  Ecole Polytechnique (Paris, France)

• 2007-2008: M.Sc in Mechanical Engineering
  Ecole Normale Superieure (Cachan, France)

• 2005-2007: B.Sc in Mechanical Engineering
  Ecole Normale Superieure & Paris 6 University (Paris, France)

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Work Experience

2008-2011: AREVA NP (Paris, France)

        R&D Engineer and PhD Student: Welding & Structural Design 

• Conducted mathematical modelling of Gas Tungsten Arc Welding on stainless steels using a multiphysics approach. Studied the impact of gravity , filler metal and chemical composition of the alloy on the welded joint.
• Carried out numerical simulations of pulsed GTAW process, studied the influence of welding parameters on both the final weld shape and the possible defects to avoid fractures.
• Studied Narrow Gap GTA welding. Applied the numerical model to the assembly of steam generators in EPR power plants.
• Conducted experiments to validate the numerical results using Infra Red Camera, High Speed Camera and a developed Matlab algorithm.
• Headed collaborative program with Delft University of Technology and coordinated experimental tests with Ecole Nationale Supérieure de Techniques Avancées (ENSTA).
• Promoted the Welding Technical Center abilities on numerical simulation with international conferences and journal publications.
• Supervised undergraduate and graduate engineering students during their Research Internship.

2008 (6 months): ENSTA-ParisTech Engineering School (Paris, France)

        Research Assistant in the Materials & Structures Group.

• Studied the heat transfer and fluid flow during arc welding. Made a multiphysics model to get initial predictions of the welded joint shape.
• Validated results with experimental test on 304L stainless steel disks.

2007 (4 months): EADS Innovation Works (Toulouse, France)

        Research Assistant in the Computational Mechanical Engineering Group.

• Studied the mathematical modeling of creep and damage behavior of composite laminates under variable mechanical loading.
• Worked on a previously developed Fortran program for the creep behavior of laminated composites and a C++ program for the damage behavior.
• Implemented a module using C++ language to study the coupling between creep and damage behavior of composite laminates assemblies for the aerospace industries.

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Research

Research Area

Today, most of the industrial and scientific issues in engineering combines several physics; heat flows, fluid flows, chemical diffusions, electromagnetic effects, metallurgical and mechanical states, etc. My primary research interest is in the area of modeling multiphysics couplings in mechanical engineering. Specifically, I work on the modeling and numerical simulation of arc welding in the assembly of nuclear power plants components. My general research question is how the numerical simulation of manufacturing processes can support engineers toward a sustainable design of products in energy, transportation, and biomedical applications.

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Current project

Numerical simulation of Gas Tungsten Arc Welding using a multiphysics approach 

Study of spot GTA welding on stainless steel: two-dimensional modelling

Mathematical modelling of the weld pool dynamics during pulsed current spot welding A transient MHD formulation is used to study the weld pool time evolution under continuous and pulsed current welding. The surface tension coefficient is dependent on both temperature and sulfur activity and is found to play an important role on the weld pool dynamics. The numerical model is used to study the influence of welding parameters (peak current, backgroud current, pulse frequency, ...) on the final weld shape.

Influence of the welding currents (peak and background) on the final weld shape, predictions (right), experiments (left).

Numerical simulation of the transfer phenomena between the arc and the weld pool using plasma physics:A transient unified formulation including the cathode, arc-plasma and anode together is introduced to study the arc weld pool couplings under pulsed current welding.

Temperature field and fluid flow during a 80/160A pulsed current welding at 1Hz Frequency.

Prediction of phases distribution and residual stresses using a multiphysics approach: metallurgical transformations model for steel is associated to the CFD model of the weld pool to predict the phase distribution in the heat affected zone and in the fusion zone. This model can be coupled to a viscoplastic model included transformation induced plasticity. Residual stresses and distortions can then be evaluated. The mechanical and metallurgical models have been applied to 16MnD5 steel (A533 steel) and 304 stainless steel welding. The mechanical model is now applied to Titanium/ceramics welding of biomechanics components.

Experimental determination of the weld pool dimensions during time using an Infra-Red camera: An IR camera is used to film the weld pool oscillations during pulsed spot GTAW on stainless steel discs. A developped image processing algorithm permits to determine the time evolution of the weld pool width.

We study the influence of different helium-argon mixtures on GTA weld pools dynamics: It is found that the addition of helium to argon increases the heat flux density on the weld axis by a factor that can reach 4.0. This induces an increase in the weld pool depth by a factor 2.0. It is also found that the addition of only 10% of argon to helium decreases the weld pool depth by 25%, which is due due to the electrical conductivity of the mixture that increases significantly when argon is added to helium. We also study the new method of alternate supply of shielding gases,  this method is found to be much more useful than the conventional method  of supplying gases mixtures.

Temperature contours and fluid flow inside the weld pool for different He-Ar mixtures. (current=180 A, arc length=3 mm, welding time=8 s).

Optimisation of pulsed welding parameters: Various otimisation algorithms are used to find the best set of input pulsed parameters (currents, frequency, ...) that produces a given weld shape and minimizes an arbitrary given criterion.

Study of moving GTA weld pools with filler metal: three-dimensional modelling

• Heat transfer and fluid flow  in moving GTA weld pools with filler metal:  (coming soon).

• Numerical simulation of the arc weld pool couplings with moving torch: (coming soon).

• Numerical end experimental study of Horizontal Narrow Gap GTA Welding: (coming soon).

Papers

Peer-Reviewed Journals

[Accepted for publication] A.Traidia, F. Roger, E. Guyot, J. Schroeder. Numerical and experimental study of arc and weld pool behaviour for pulsed GTA welding 2012. International Journal of Heat and Mass Transfer  XXX:XX

A.Traidia, F. Roger, A. Chidley, J. Schroeder, and T. Marlaud. Effect of helium addition on the heat transfer and fluid flow in GTA welding 2011. Journal of Chemistry and Chemical Engineering. 5:9, 2011.

A.Traidia, F. Roger. A computational investigation of different helium supplying methods for the improvement of GTA welding 2011. Journal of Materials Processing Technology  211 : 1563-1552

A.Traidia, F. Roger. Numerical and experimental study of arc and weld pool behaviour for pulsed GTA welding 2010.  International Journal of Heat and Mass Transfer  54 : 2163-2179 (Corrigendum)

 A.Traidia, F. Roger, E. Guyot. NOptimal parameters for pulsed gas tungsten arc welding in partially and fully penetrated weld pools 2010. International Journal of Thermal Sciences. 49 : 1197-1208 .


Conferences proceedings


M. Song, M. Alfano, G. Lubineau, A. Traidia. An overview of available models for Hydrogen Induced Cracking in steels. !4th Middle East Corrosion Conference, by NACE International. Bahrain 2012.

A.Traidia, F. Roger. Effect of helium-argon mixtures on the heat transfer and fluid flow in Gas Tungsten Arc Welding. International Conference on Fluid Mechanics, Heat Transfer and Thermodynamics 2011. By World Academy of Science Engineering and Technology. Dubai (UAE).

F.Roger, A.Traidia, B.Reynier. Heat transfer, fluid flow, and metallurgical transformations in arc welding: Application to 16MND5 steel. International Conference on Fluid Mechanics, Heat Transfer and Thermodynamics 2011. By World Academy of Science Engineering and Technology. Dubai (UAE). 

A.Traidia, F.Roger, J. Schroeder. Three Dimensional Modeling of the Weld Pool Behavior During GTA Welding with Filler Metal . Europen Conference Comsol Multiphysics 2010. Paris (France). 

A.Traidia, F.Roger. A transient unified model of arc-weld pool couplings during pulsed spot GTA welding. American Conference Comsol Multiphysics 2010. Boston (USA).

F. Roger, A. Traidia. Modeling residual stresses in arc welding. American Conference Comsol Multiphysics 2010. Boston (USA).

A. Chidley, F. Roger, A.Traidia. Thermo-mechanical behavior of heat exchangers. American Conference Comsol Multiphysics 2010. Boston (USA).

A.Traidia, F.Roger, E.Guyot. Numerical simulation of pulsed TIG welding. Partial and full penetration. European Conference Comsol Multiphysics 2009. Milan (Italy).

Links

KAUST University

Ecole Polytechnique

COMSOL Community

Contact

Professional address:

Abderrazak Abderrazak
COHMAS Laboratory, Physical Science and Engineering Division
King Abdullah University of Science and Technology (KAUST)
Al-Jazri Blg. 4, Level 0
Thuwal, 23955-6900
Kingdom of Saudi Arabia

Phone: +396 564 642 421

Email: abderrazak.traidia@doc.polytechnique.org