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Novikov, A. (author)Safe and sustainable exploitation of geo-energy resources requires not only a comprehensive evaluation of the performance and economics of the corresponding projects but also the assessments of the associated risks, including the risk of induced seismicity. Indeed, seismic events may arise from the reactivation of natural faults and fractures...doctoral thesis 2024
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Civiero, R. (author), Perez-Rafols, F. (author), Nicola, L. (author)The effect of the presence of a passivation layer on a metal rough surface during contact loading is investigated by means of dislocation dynamics simulations. The metal body is modeled as an FCC single crystal with a self-affine rough surface that is either bare, or covered by a thin coating, impenetrable to dislocations. This analysis...journal article 2023
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Pérez-Ràfols, Francesc (author), van Dokkum, J.S. (author), Nicola, L. (author)Viscoelasticity and roughness are among the possible causes of the adhesive hysteresis displayed by soft contacts. Viscoelasticity causes an increased effective work of adhesion due to stiffening of the contact, while roughness is responsible for elastic instabilities. Herein, we explore the interplay between viscoelasticity and roughness by...journal article 2023
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Mojto, Maroš (author), Cabboi, A. (author)This study aims at shedding light on the mechanical behaviour of a prototype monopile–wind turbine tower connection, constituted by a slip joint. Selected examples of data set recorded during a long term monitoring campaign are illustrated and discussed. The data set encompass axial and hoop stresses measured over the slip joint area,...journal article 2023
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KOURTIS, YANNIS (author)Pile tip damage due to impact with an object (boulder) during the driving process of monopiles is of main concern in the offshore wind sector. Numerical modelling could accurately describe this failure mechanism and used as a tool in practice but also for the development of appropriate guidelines. In this research project, dynamic Finite Element...master thesis 2022
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Novikov, A. (author), Voskov, D.V. (author), Khait, M. (author), Hajibeygi, H. (author), Jansen, J.D. (author)We present a scalable collocated Finite Volume Method (FVM) to simulate induced seismicity as a result of pore pressure changes. A discrete system is obtained based on a fully-implicit fully-coupled description of flow, elastic deformation, and contact mechanics at fault surfaces on a flexible unstructured mesh. The cell-centered collocated...journal article 2022
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Aramfard, Mohammad (author), Pérez-Ràfols, Francisco (author), Nicola, L. (author)A seamless 2D dual-scale computational scheme is developed to study contact problems. The model consists of an atomistic domain close to the contact, coupled with an elastic continuum domain away from the contact. The atomistic formulation provides a description of the contact interaction through interatomic potentials and permits to capture...journal article 2022
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- Parayil Venugopalan, S. (author) doctoral thesis 2019
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Parayil Venugopalan, S. (author), Irani, N. (author), Nicola, L. (author)Persson's theory allows for a fast and effective estimate of contact area and contact stress distributions when a flat and a self-affine rough surface are pressed into contact. For elastic bodies, the results of the theory have been shown to be in very good agreement with rather costly simulations. The theory has also been extended to plastic...journal article 2019
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van Dokkum, J.S. (author), Nicola, L. (author)The contact mechanical response of various polymers is controlled by the viscoelastic behavior of their bulk and the adhesive properties of their interface. Due to the interplay between viscoelasticity and adhesion it is difficult to predict the contact response, even more when surfaces are rough. Numerical modeling could be of assistance in...journal article 2019
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Parayil Venugopalan, S. (author), Nicola, L. (author)Although indentation of elastic bodies by self-affine rough indenters has been studied extensively, little attention has so far been devoted to plasticity. This is mostly because modeling plasticity as well as contact with a self-affine rough surface is computationally quite challenging. Here, we succeed in achieving this goal by using Green...journal article 2019
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Gallyamov, Emil (author)In recent years, humanity became strongly dependent on the deep subsurface. It can be used as the energy source as well as the storage facility. At some stage, both listed applications require injection of fluid or gas into the subsurface porous media. Under certain conditions, it may provoke growth of hydraulic fractures. The appearance of...master thesis 2017
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Parayil Venugopalan, S. (author), Nicola, L. (author), Müser, Martin H. (author)The Green's function molecular dynamics (GFMD) method for the simulation of incompressible solids under normal loading is extended in several ways: shear is added to the GFMD continuum formulation and Poisson numbers as well as the heights of the deformed body can now be chosen at will. In addition, we give the full stress tensor inside the...journal article 2017
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Parayil Venugopalan, S. (author), Mueser, Martin H. (author), Nicola, L. (author)Metals deform plastically at the asperity level when brought in contact with a counter body even when the nominal contact pressure is small. Modeling the plasticity of solids with rough surfaces is challenging due to the multi-scale nature of surface roughness and the length-scale dependence of plasticity. While discrete-dislocation plasticity ...journal article 2017
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Noorlandt, R.P. (author)The seismic method is an important indirect method to investigate the subsurface of the earth. By analyzing how the earth affects the propagation of mechanical waves, the structure of the earth and its seismic properties can be inferred. The seismic vibrator is the most commonly used land source in active-source exploration and monitoring to...doctoral thesis 2016
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Pantev, I. (author)In recent years, the Material Point Method has emerged as a promising alternative to the Finite Element Method for solving problems involving localised deformations, large displacements or rotations, fracture, contact/impact problems and others. FEMhas been a staple of engineering disciplines both in academia and industry for decades, however...master thesis 2016
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Sun, F. (author)The ultimate objective of this work is to gain a better understanding of the plastic behavior of rough metal surfaces under contact loading. Attention in this thesis focuses on the study of single and multiple asperities with micrometer scale dimensions, a scale at which plasticity is known to be size dependent. The asperities have very simple...doctoral thesis 2016
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De Looij, H.R. (author)The CONTACT software is capable of analyzing contact problems between two objects. In this thesis, we will show how CONTACT can be used for time-dependent contact problems. An algorithm will be designed which is capable of computing the deformation that occurs as the result of a train moving over a bridge.master thesis 2015
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De Looij, H.R. (author)The CONTACT software is capable of analyzing contact problems between two objects. In this thesis, we will show how CONTACT can be used for time-dependent contact problems. An algorithm will be designed which is capable of computing the deformation that occurs as the result of a train moving over a bridge.master thesis 2015
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Zhao, J. (author)Rail transportation plays an important role in our everyday life, and there is fast development and modernization in the railway industry to meet the growing demand for swifter, safer and more comfortable trains. At the same time, the security of train operation and the maintenance of rails have to be considered. A lot of research on these...doctoral thesis 2015