The last decade has witnessed a boom in offshore infrastructures, including not only oil and gas platforms and submarine pipelines due to the shift of energy exploration from onshore to offshore but also offshore wind farms, offshore electricity grid infrastructure, and submarine communication cables and routes. This boom significantly enhances the importance of the estimation of potential submarine landslides and their consequences. It is true that submarine landslides may have a unexpectedly long travel distance and damage infrastructure thousands of kilometers away. However numerical modelling of the entire process of submarine landslides is a long-standing challenge. In addition to constitutive models for describing both solid-like and fluid-like behaviour of sediments, it requires also advanced numerical approaches capable of tackling extremely large deformation experienced by materials as well as interactions between structures, seawater, and sediments. This project is motivated by these challenges and aims to develop innovative continuum models and numerical approaches for simulating submarine landslides and their consequences. A unified mixed Lagrangian finite element formulation will be derived for handling solid mechanics (infrastructure), fluid dynamics (seawater), and poromechanics (sediments). Viscoeplastoplastic constitutive models will be developed for capturing the solid-fluid transitional behaviour of sediments. The proposed formulation and models will be implemented on a high performance computing based numerical platform within the framework of the particle finite element method for fully coupled analyses of submarine landslides. The intended outcome is a computational tool that can simulate the complete process of real-world submarine landslides, ranging from the initiation of failure through the sliding process to the final deposition and predicting their impact on offshore infrastructures.

Nuclear waste is generated during the operation and maintenance of nuclear power plants. The waste is first transferred to an interim storage, where it remains for tens of years, till radioactivity and heat generation of the spent fuel is reduced to a level that allows its final disposal. It is generally accepted that the final waste will be disposed of in a deep geological repository. However, not a single country worldwide has an operational underground repository. In the design process of these repositories, simulation tools capable to model their long term behavior (hundreds of years) are required. However, such simulations are extremely challenging, due to the complicated nature of the physical phenomena of multiscale and multiphysics nature. Current numerical tools being used by some of the most advanced deep repository projects use CODE_BRIGHT (developed at UPC-CIMNE), a very rich code in terms of modelling capabilities, which benefits from 20 years of intensive validation against in-situ experiments. However, CODE_BRIGHT is a serial structured FORTRAN 90 code with very limited capabilities in terms of parallel performance. As a result, actual analyses of prototypical deep repositories require strong and not validated simplification assumptions, in order to reduce by some orders of magnitude the computational cost of the target simulations. In this project, we want to change the situation by developing extremely scalable simulation software for nuclear waste management in repositories. The strategy is to port CODE_BRIGHT modelling capabilities to FEMPAR, the extremely scalable scientific computing code that resulted from the Starting Grant COMFUS. The result of this work will be a new software that (1) produces the same results as CODE_BRIGHT for a wide set of benchmark tests (to validate the code), and (2) with proven excellent scalability on hundreds of thousands of processors.

The project aims to develop a new integrated approach for designing and optimising innovative lightweight structures. In recent years, material engineering has introduced a new class of material with mechanical properties not found in nature: metamaterials. Their exceptional properties are valuable in designing even more performant and sustainable lightweight structures. The complex design achieved by metamaterials is obtained by Additive Manufacturing (AM) techniques. The effective mechanical properties are computed using multiscale homogenization approaches. Topology optimization at a multiscale level brings a great variety of functionalized metamaterial. However, the multiscale approach has been fully developed only for solid models at a heavy computational cost. The AM process has its own manufacturability constraints that limit the optimization process. The defects and material limits need to be addressed to guarantee the component functionality and safety. The IRMA project aims to provide a new approach for a fully integrated design of innovative lightweight structures. The specific objectives are: 1. To formulate a refined approach for the multiscale structural behaviour of innovative lightweight structures; 2. To implement an integrated numerical solution to address micro-structural defects and limits of the metamaterials in lightweight structures; 3. To develop a new numerical optimization method that considers macro- and micro- model constraints to improve the design of lightweight structures using metamaterials. The project is thoroughly designed to maximize training and transfer of knowledge to the host group. Project management, risks, communication and dissemination activities, including industrial partners, are carefully designed. My supervisor's experience, the full integration in his group (CAMMS), and the CIMNE-CERCA resources are the perfect ingredients for developing the IRMA project.