Friday, 15 October 2021 12:00
VIRTUAL PRESENTATION BY
Dr Giovanni Zucco and Dr Ryan Arevalo
School of Engineering & Department of Chemical Sciences
University of Limerick
ABSTRACT – Presentation 1
The geometrically nonlinear behaviour of thin-walled aircraft structures is crucial in the design procedure. Many of these structures exhibit a certain degree of symmetry, which plays an integral role in their elastic post-buckling analysis. In this presentation, a new asymptotic method for tracing the geometrically nonlinear response of elastic thin-walled aircraft structures is proposed. In particular, a Koiter inspired multi-modal approach that exploits the symmetry properties of a structural system for simplified, yet accurate, post-buckling analysis is presented. This approach is named the Curie-Koiter method.
Firstly, in the context of the Group Representation Theory, symmetry groups for nonlinear elastic structural systems are discussed. As such, a general definition for classifying the symmetry group of a given structural system is provided on the basis of the symmetry properties of its geometry, stiffness distribution, loading and boundary conditions. Then, in the framework of a multi-modal Koiter inspired theory, Curie’s principle is invoked for describing the nonlinear relationship between the symmetry groups of a structural system and related pre-buckling and buckling deformation patterns. Then, once the symmetry group of the structural system is detected, Curie’s principle is re-invoked for finding the relationship between linear buckling modes and post-buckled deformation of the structure. Subsequently, for the first time, a criterion for a priori identification of the set of buckling modes that best describe the post-buckling behaviour of the system under consideration is provided. Then, based on this information, a simplified asymptotic description is obtained by retaining only the subset of the most representative buckling modes in subsequent analysis. Finally, the new computed equilibrium paths are compared to benchmark results using the commercial finite element software ABAQUS and the computational advantages given by using the Curie-Koiter approach are outlined.
ABSTRACT – Presentation 2
Methane activation is one of the most important industrial processes in a modern-day society as it plays a key role in the production of syngas that is used to make a wide spectrum of hydrocarbons and alcohols that sustain the energy and chemical needs of humankind. Using density functional theory-based calculations and kinetic Monte Carlo simulations, the reaction mechanism of methane decomposition and reforming processes on various surfaces are investigated. Focusing on addressing the carbon formation or “coking” reaction on stepped Ni surface, the important electronic factors that govern the selectivity of Ni surface for methane decomposition toward atomic carbon were found. Interestingly, substituting the specific subsurface Ni atoms with other elements were found to dramatically change the reaction mechanism of methane decomposition on the surface, suggesting a new approach to catalyst design for hydrocarbon reforming applications.
ABOUT THE PRESENTERS
Dr Giovanni Zucco is a structural-civil engineer with a PhD in Computational Mechanics. Currently, he is a Lecturer below the bar in Composite Aircraft Structures Engineering at the School of Engineering, University of Limerick. From February 2017 to August 2021, Giovanni worked as a post-doctoral researcher at the University of Limerick under the supervision of Professor Paul M. Weaver. His scientific interests are mainly buckling and post-buckling analysis of lightweight composite structures. He is an internationally recognised expert in Koiter’s analysis of thin-walled structures. He has authored 27 refereed journal articles and more than 25 conference proceedings. His h-index on Scopus is 11. Recently, as a member of the VARICOMP project (PI Professor Paul M. Weaver), Giovanni collaborated with Airbus UK. ORCID: https://orcid.org/0000-0002-1230-2423
Dr Ryan Arevalo is a member of the research group of Dr Matthias Vandichel of the Department of Chemical Sciences and the Bernal Institute, University of Limerick. Ryan earned his PhD in Quantum Engineering Design from Osaka University in Japan.
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