Thesis defense : Ahmed EL KERIM

The analysis and design of complex structures can be time-consuming and computationally inten­sive, especially for large-scale problems. Domain decomposition methods have become a powerful tool in structural mechanics to address these chal­lenges. They divide a computational task into smaller and independent tasks that can be exe­cuted in parallel. Recent work shows many advan­tages when coupling asynchronous parallel compu­tation with these methods, overcoming the limita­tions of classical synchronous methods and result­ing in more efficient use of computational resources and better parallelism, resulting in faster solution times.

This research work presents the first asyn­ch ronous version of non-intrusive global/local coupling, capable of efficiently processing multiple possibly adjacent patches. A new interpretation of the coupling by a primai domain decomposi­tion method is proposed. The convergence of re­laxed asynchronous iteration in the linear and non­linear cases using paracontractions techniques is also demonstrated. Subsequently, an implementa­tion based on MPI-RDMA techniques is proposed. This implementation is then confronted with an accelerated synchronous method. The implemen­tation is illustrated on several linear elliptic prob­lems, such as those encountered in thermal and elasticity studies, and on nonlinear problems, such as nonlinear elliptic and plasticity problems. The asynchronous paradigm eliminates many global/lo­cal coupling performance problems.

 

Composition of the jury

• Mr Pierre SPITERI, Professor Emeritus - Institut National Polytechnique de Toulouse (Rapporteur)
• Mr Daniel SZYLD, Full professor - Temple University of Philadelphia (Rapporteur)
• Mr. Pierre-Alain BOUCARD, Professor - École normale supérieure Paris-Saclay - Université Paris-Saclay (Examiner)
• Mrs. Nicole SPILLANE, CNRS Research Fellow - Centre de Mathématiques Appliquées de l'Écolepolytechnique (Examiner)
• Mr. Robin BOUCLIER, Examiner Senior Lecturer HDR - National Institute of Applied Sciences of Toulouse (Examiner)
• Mr. Julien YVONNET, University Professor - Gustave Eiffel University (Examiner)
• M. Augustin PARRET-FREAUD, Doctor-Engineer - Safran Tech (Guest)
• M. Pierre GOSSELET, CNRS Research Director - University of Lille (Thesis Director)
• M. Frédéric MAGOULES, University Professor - CentraleSupélec - Université Paris-Saclay (Thesis Director)

 

Keywords

Non-invasive Global Local coupling, Asynchronous domain decomposition, Linear and non linear domain decomposition method, Paracontraction techniques, MPI-RDMA.