Sfoglia per Autore "Zervaki, A. D."
Items 1-20 di 22
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Analysis of heat affected zone in Al1239 and Al2198 laser welds using inverse modeling
Zervaki, A. D.; Haidemenopoulos, G. N.; Lambrakos, S. G. (2013)Case study analyses of Al2139 and Al2198 laser welds are presented. These analyses demonstrate the concept of constructing parameter spaces for prediction of properties within the Heat Affected Zone (HAZ) of welds using ... -
Analysis of heat affected zone in welded aluminum alloys using inverse and direct modeling
Zervaki, A. D.; Haidemenopoulos, G. N.; Lambrakos, S. G. (2008)The concept of constructing parameter spaces for process control and the prediction of properties within the heat affected zone (HAZ) of welds using inverse modeling is examined. These parameter spaces can be, in principle, ... -
Case-Study Inverse Thermal Analyses of Al2139 and Al2198 Electron Beam Welds
Zervaki, A. D.; Stergiou, V.; Lambrakos, S. G. (2013)Case study inverse thermal analyses of A12139 and Al2198 electron beam welds are presented. These analyses represent a continuation of previous studies using laser beam welds, but provide accessibility to different regions ... -
Case-Study Inverse Thermal Analyses of Al2139 Laser Welds
Zervaki, A. D.; Haidemenopoulos, G. N.; Vriami, D. P.; Lambrakos, S. G. (2012)Case study inverse thermal analyses of A12139 laser welds are presented. These analyses employ a numerical methodology that is in terms of analytic and numerical basis functions for inverse thermal analysis of steady state ... -
Case-Study Inverse Thermal Analyses of Al2198 Laser Welds
Zervaki, A. D.; Haidemenopoulos, G. N.; Vriami, D. P.; Lambrakos, S. G. (2012)In this article, case-study inverse thermal analyses of Al2198 laser welds are presented. These analyses employ a numerical methodology, that is, in terms of analytic and numerical basis functions for inverse thermal ... -
Computational kinetics simulation of the dissolution and coarsening in the HAZ during laser welding of 6061-T6 Al-alloy
Zervaki, A. D.; Haidemenopoulos, G. N. (2007)Laser beam welding (LBW) has become common practice in the production lines of several industrial sectors including the electronics, domestic appliances, and automotive industries. The advantages of LBW over conventional ... -
Corrosion of exposed rebars, associated mechanical degradation and correlation with accelerated corrosion tests
Papadopoulos, M. P.; Apostolopoulos, C. A.; Zervaki, A. D.; Haidemenopoulos, G. N. (2011)In a large number of steel reinforced concrete buildings in Greece, spalling of the cement has left the steel reinforcement (rebars) exposed to the atmosphere. This has led to corrosion of the exposed rebars, especially ... -
Effects of temper condition and corrosion on the fatigue performance of a laser-welded Al-Cu-Mg-Ag (2139) alloy
Kermanidis, A. T.; Zervaki, A. D.; Haidemenopoulos, G. N.; Pantelakis, S. G. (2010)The effects of temper condition and corrosion on the fatigue behavior of a laser beam welded Al-Cu-Mg-Ag alloy (2139) have been investigated. Natural aging (T3 temper) and artificial aging (T8 temper) have been applied ... -
Fatigue failure investigation of pre-corroded and laser-welded Al-Cu-Mg-Ag Alloy with different temper condition
Zervaki, A. D.; Kermanidis, A. T.; Haidemenopoulos, G. N.; Pantelakis, S. G. (2010)The fatigue failure mechanisms of pre-corroded, laser beam welded Al-Cu-Mg-Ag alloy in different temper conditions (T3,T8) have been investigated. Aging influences the corrosion behavior of laser welds. In the T3 temper, ... -
Fatigue performance of pre-corroded 6xxx aluminum alloy laser beam welds with dissimilar heat treatment
Kermanidis, A. T.; Zervaki, A. D.; Modas, V.; Chamos, A. N.; Pantelakis, Sp G. (2014)The role of existing corrosion damage on the fatigue performance of 6156 AA laser beam welds in T3 state, with additional post weld heat treatment T8, has been assessed. The welds were subjected to salt fog environment for ... -
Fracture behavior of bimetallic Al-Cu LBW joints
Haidemenopoulos, G. N.; Zervaki, A. D.; Kamoutsi, H.; Hontzopoulos, E.; Mangana, F. (2013)Pulsed laser spot welding of copper tubing to aluminum sheet is currently used for the construction of solar thermal absorbers. The bimetallic joints should withstand high thermal stresses during the operation of the ... -
The influence of salt fog exposure on the fatigue performance of Alclad 6xxx aluminum alloys laser beam welded joints
Kermanidis, A. T.; Zervaki, A. D.; Haidemenopoulos, G. N.; Pantelakis, S. G. (2010)Laser welding is increasingly used for the fabrication of lightweight and cost-effective integral stiffened panels in modern civil aircraft. As these structures age in service, the issue of the effect of corrosion on their ... -
Inverse Thermal Analysis of Heat-Affected Zone in Al2129 and Al2198 Laser Welds
Zervaki, A. D.; Haidemenopoulos, G. N.; Lambrakos, S. G. (2013)Case study analyses of A12139 and Al2198 laser welds are presented. These analyses demonstrate the concept of constructing parameter spaces for prediction of properties within the heat-affected zone (HAZ) of welds using ... -
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 ... -
Laser-beam surface transformation hardening of hypoeutectoid Ck-60 steel
Katsamas, A. I.; Zervaki, A. D.; Haidemenopoulos, G. N. (1997)A carbon dioxide laser with a power of 1.5 KW was employed for surface hardening of a hypoeutectoid Ck-60 steel. The microstructures and hardness profiles were determined as a function of power density and laser beam travel ... -
A Numerical Method for Inverse Thermal Analysis of Steady-State Energy Deposition in Plate Structures
Lambrakos, S. G.; Zervaki, A. D.; Haidemenopoulos, G. N. (2012)A numerical method for inverse thermal analysis of steady-state energy deposition in plate structures is constructed according to the general physical characteristics of energy deposition within a volume of material from ... -
Rolling contact fatigue of rails
Haidemenopoulos, G. N.; Zervaki, A. D.; Giannakopoulos, A. (2013)Rolling contact fatigue (RCF) has been of increasing concern in the recent years regarding the safe operation of high-speed railway track with high traffic intensity. The present paper summarizes the results of an on-going ... -
Sensitivity issues concerning inverse heat transfer analysis of welds
Lambrakos, S. G.; Jones, H. N.; Zervaki, A. D.; Haidemenopoulos, G. N. (2009)The construction of a general parameterization for inverse analysis of welding processes using incomplete or minimal experimental data, although demonstrated in principle, has yet to be firmly established. The structure ... -
Simulation of dissolution and coarsening in the HAZ of 6061 Al- alloy during laser welding
Zervaki, A. D.; Haidemenopoulos, G. N. (2005)Application of laser beam welding (LBW) in heat treatable aluminum alloys causes softening of the heat affected zone (HAZ). This loss in hardness, reflects the relevant microstructural changes due to dissolution and ... -
Simulation of the transformation of iron intermetallics during homogenization of 6xxx series extrudable aluminum alloys
Haidemenopoulos, G. N.; Kamoutsi, H.; Zervaki, A. D. (2012)A computational simulation of the beta-AlFeSi to alpha-AlFeSi transformation has been performed in this work by integrating the process steps of solidification and homogenization. The composition profiles of alloying ...