Πλοήγηση ανά Συγγραφέα "Giannakopoulos, A. E."
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Indentation of plastically graded substrates by sharp indentors
Giannakopoulos, A. E. (2002)The present paper investigates the indentation of plastically graded substrates by sharp indentors. Contact analysis of plastically graded surfaces can be particularly useful in the design of load-bearing devices such as ... -
The influence of initial elastic surface stresses on instrumented sharp indentation
Giannakopoulos, A. E. (2003)The present work examines the influence of pre-existing, elastic surface stresses on instrumented sharp indentation. The surface is modeled as a homogeneous and isotropic elastoplastic solid in the context of linear ... -
Investigation of rolling contact fatigue cracks in a grade 900A rail steel of a metro track
Haidemenopoulos, G. N.; Zervaki, A. D.; Terezakis, P.; Tzanis, J.; Giannakopoulos, A. E.; Kotouzas, M. K. (2006)Rolling contact fatigue (RCF) has been of increasing concern in the recent years in respect of the safe operation of high-speed railway track with high traffic intensity. The present paper summarizes the results of the ... -
Micropolar 2D Elastic Cables with Applications to Smart Cables and Textiles
Kordolemis, A.; Giannakopoulos, A. E. (2014)Elastic cables are structural elements with a one-sided constitutive law (compression is not allowed) that obtain their equilibrium configuration by adjusting their shape to satisfy static equilibrium. The loading of a ... -
The Modified Rockwell Test: A New Probe for Mechanical Properties of Metals
Baxevani, E. A.; Giannakopoulos, A. E. (2009)In the present work a novel methodology is proposed, based on the combination of the Rockwell and the Vickers tests, to provide estimates of the mechanical properties of metal substrates. The analysis is based on some novel ... -
Molecular dynamics simulation on flows in nano-ribbed and nano-grooved channels
Sofos, F.; Karakasidis, T. E.; Giannakopoulos, A. E.; Liakopoulos, A. (2015)We present molecular dynamics simulation results on fluid and transport properties for nanochannel flows. The upper channel wall is constructed from periodic roughness elements and flows are simulated both in longitudinal ... -
Plane asymptotic crack-tip solutions in gradient elasticity
Aravas, N.; Giannakopoulos, A. E. (2009)An asymptotic crack-tip solution under conditions of plane strain is developed for a material that obeys a special form of linear isotropic strain gradient elasticity. In particular, an elastic constitutive equation of the ... -
A quasi-continuum multi-scale theory for self-diffusion and fluid ordering in nanochannel flows
Giannakopoulos, A. E.; Sofos, F.; Karakasidis, T. E.; Liakopoulos, A. (2014)We present a quasi-continuum self-diffusion theory that can capture the ordering effects and the density variations that are predicted by non-equilibrium molecular dynamics (NEMD) in nanochannel flows. A number of properties ... -
A reciprocity theorem in linear gradient elasticity and the corresponding Saint-Venant principle
Giannakopoulos, A. E.; Amanatidou, E.; Aravas, N. (2006)In many practical applications of nanotechnology and in microelectromechanical devices, typical structural components are in the form of beams, plates, shells and membranes. When the scale of such components is very small, ... -
The Relation of the Vickers Hardness With the Loading Stiffness of Instrumented Vickers Indentation of Metal Substrates
Baxevani, E. A.; Giannakopoulos, A. E. (2010)The present paper presents a relation between the vickers hardness HV and the loading stiffness C of instrumented vickers indentation of metal substrates. The relation is based on the fact that the nonaxisymmetry of the ... -
A second gradient elasto-plastic model for fatigue of small-scale metal components
Stamoulis, K.; Giannakopoulos, A. E. (2010)Purpose - As the dimensions of structures are scaled down to the micro- and nano-domains, the mechanical behavior becomes size dependent and thus, the classical elasticity solutions cannot be expected to hold. In particular, ... -
Size effects on strength, toughness and fatigue crack growth of gradient elastic solids
Stamoulis, K.; Giannakopoulos, A. E. (2008)The present study investigates the microstructural size effect on the strength of a bar under axial loading, and on the toughness and crack growth of a beam under three-point bending within the framework of strain gradient ... -
Spherical indentation of incompressible rubber-like materials
Giannakopoulos, A. E.; Triantafyllou, A. (2007)In recent years, indentation tests have been proven very useful in probing mechanical properties of small volumes of materials. However, a class of materials that very little has been done in this direction is rubber-like ... -
Structural analysis of gradient elastic components
Giannakopoulos, A. E.; Stamoulis, K. (2007)The present study investigates the size effects in the problems of cantilever beam bending and cracked bar tension within the gradient elasticity framework. Analytical solutions for metrics that characterize both the ... -
Structural analysis using a dipolar elastic Timoshenko beam
Triantafyllou, A.; Giannakopoulos, A. E. (2013)In recent years, several non-local beam theories have emerged in trying to model stiffness and strength phenomena observed in micro-beams used in micro-mechanical systems (MEMS) and sensors. Of particular importance are ... -
A structural gradient theory of torsion, the effects of pretwist, and the tension of pre-twisted DNA
Giannakopoulos, A. E.; Aravas, N.; Papageorgopoulou, A.; Vardoulakis, I. (2013)A structural gradient theory of torsion of thin-walled beams is developed. A non-local estimate of the mean value of the angle of twist of the beam leads to a shear gradient that is energetically consistent with a bi-moment, ... -
A study of size effects and length scales in fracture and fatigue of metals by second gradient modelling
Stamoulis, K.; Giannakopoulos, A. E. (2012)As the dimensions of structures are scaled down to the micro- and nano-domains, the mechanical behaviour becomes size dependent and thus, we cannot expect the classical elasticity solutions to hold. In particular, recent ... -
Study on the dynamic behavior of arterial end-to-end anastomosis
Roussis, P. C.; Giannakopoulos, A. E.; Charalambous, H. P. (2014)Vascular disorders, such as atherosclerosis and aneurysms are treated by vascular surgery operations, and involve the stitching of disconnected human arteries with themselves or with artificial grafts. Stitching techniques ... -
Suture Line Response of End-to-Side Anastomosis: A Stress Concentration Methodology
Roussis, P. C.; Giannakopoulos, A. E.; Charalambous, H. P. (2015)End-to-side vascular anastomosis has a considerable complexity regarding the suturing of the juncture line between the artery and the graft. The present study proposes a stress–concentration methodology for the prediction ... -
Unified description of size effects of transport properties of liquids flowing in nanochannels
Giannakopoulos, A. E.; Sofos, F.; Karakasidis, T. E.; Liakopoulos, A. (2012)The present work connects transport properties of simple fluids flowing in nanochannels: the diffusion coefficient, the shear viscosity and the thermal conductivity. We used non-equilibrium molecular dynamics (NEMD) ...