1. |
Nowak M., Mulewska K.^{♦}, Azarov A.^{♦}, Kurpaska ^{♦}, Ustrzycka A., A peridynamic elasto-plastic damage model for ion-irradiated materials,
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES, ISSN: 0020-7403, DOI: 10.1016/j.ijmecsci.2022.107806, No.107806, pp.1-46, 2022Abstract: This study presents the novel peridynamic constitutive relations formulated in order to predict the plastic deformation and damage evolution in irradiated materials. The plastic behaviour of the material in which radiation induced defects contribute to the defined peridynamic porosity is described by the Gurson-Tvergaard-Needleman (GTN) yield criterion with irradiation hardening. The definition of peridynamic porosity is proposed as a volume of discontinuities created in the volume of peridynamic particles. The new constitutive relations for irradiation hardening based on the dilatational part of elastic strain energy are formulated. The physical relevance of coupling the porosity with the nonlinear irradiation hardening is discussed. The expressions for the yield function, kinetics of evolution of radiation induced porosity, irradiation hardening and plastic flow rule are derived in terms of the peridynamics variables. The peridynamic predictions are calibrated based on the experimental data obtained during the advanced experimental campaigns dedicated to irradiated materials to verify the validity of the proposed constitutive model. Ion irradiation campaigns were carried out to mimic the effects of neutron irradiation. A series of indentation experiments were conducted to elucidate the effects of material structure modification and assess the hardening effect originating from radiation defects. Keywords: Peridynamics,Constitutive modeling,Radiation induced damage,Peridynamic porosity,Gurson yield function,Irradiation hardening,Ion irradiation,Nano-indentation test Affiliations:
Nowak M. | - | IPPT PAN | Mulewska K. | - | National Centre for Nuclear Research (PL) | Azarov A. | - | other affiliation | Kurpaska | - | National Centre for Nuclear Research (PL) | Ustrzycka A. | - | IPPT PAN |
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2. |
Dominguez-Gutierrez F.J.^{♦}, Ustrzycka A., Xu Q.^{♦}, Alvarez-Donado R.^{♦}, Papanikolaou S.^{♦}, Alava M.J.^{♦}, Dislocation nucleation mechanisms during nanoindentation of concentrated FeNiCr alloys: unveiling the effects of Cr through molecular simulations,
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING, ISSN: 0965-0393, DOI: 10.1088/1361-651X/ac9d54, Vol.30, No.085010, pp.1-15, 2022Abstract: Fe-based alloys with high chromium and nickel concentrations are very attractive for efficient energy production in extreme operating conditions. We perform molecular dynamics (MD) simulations of nanoindentation on fcc FeNiCr multicomponent materials. Equiatomic FeNi, Fe55Ni19Cr26, and Fe74Ni8Cr18 are tested by using established interatomic potentials and similar conditions, for the elucidation of key dislocation nucleation mechanisms and interactions. Generally, we find that the presence of Cr in these alloys reduces the mobility of prismatic dislocation loops, and increases their area, regardless of crystallographic orientation. Dislocation nucleation and evolution is tracked during mechanical testing as a function of nanoindentation strain and Kocks–Mecking continuum modeling displays good agreement with MD findings. Furthermore, the analysis of geometrically necessary dislocations (GNDs) is consistent with the Ma–Clarke’s model at depths lower than 1.5 nm. The presence of Cr leads to a decrease of the GND density with respect to Cr-less FeNi samples, thus we find that Cr is critically responsible of increasing these alloys’ hardness. Post-indentation impression maps indicate that Ni–Fe–Cr compositions display strain localization and hardening due to high Cr concentration. Affiliations:
Dominguez-Gutierrez F.J. | - | other affiliation | Ustrzycka A. | - | IPPT PAN | Xu Q. | - | other affiliation | Alvarez-Donado R. | - | other affiliation | Papanikolaou S. | - | other affiliation | Alava M.J. | - | other affiliation |
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3. |
Ustrzycka A., Physical mechanisms based constitutive model of creep in irradiated and unirradiated metals at cryogenic temperatures,
Journal of Nuclear Materials, ISSN: 0022-3115, DOI: 10.1016/j.jnucmat.2021.152851, Vol.548, pp.152851-1-15, 2021Abstract: The present work describes the physical mechanisms of low temperature creep in irradiated and unirradiated metals. The slow inelastic deformations of solids under stress below the yield stress of the material are considered. For the problem of creep at cryogenic temperatures, the classical creep models are not enough. The purpose of this paper is to formulate a physically-based constitutive model of creep for irradiated materials at cryogenic temperatures (liquid nitrogen 77 K, liquid helium, 4.2 K) based on the idea that a dislocation held up by a potential barrier can pass through it owing to the quantum-mechanical tunnelling effect. The problem is novel in the context of recognition of physical mechanisms taking place at cryogenic temperatures leading to the evolution of radiation induced defects under mechanical loads. Creep produced by the expansion of irradiation induced dislocation loops is considered. The kinetic law for evolution of a dislocation loop is proposed using the mechanism of development of a dislocation line over Peierls stress hills. Also, creep produced by the elastic interaction of a radiation induced point defects with existing dislocations in materials is regarded. Predicted creep rate behaviour as a function of stresses and dpa are presented which would need to be validated with data in irradiated materials. Moreover, the new constitutive model of low temperature creep in unirradiated materials is formulated. The Glen-Mott quantum mechanical dislocation tunnelling effect allows extending the theory to the liquid helium temperature range. For this case of unirradiated materials, the creep curves validated experimentally for copper and stainless steel in cryogenic temperature are shown. Keywords: creep in the proximity of absolute zero,irradiation creep,quantum-mechanical tunneling effect,cryogenic temperatures,low thermal energy,Peierls stress hills Affiliations:
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4. |
Kowalewski Z.L., Szymczak T.^{♦}, Ustrzycka A., Współczesna interferometria plamkowa na tropach przyczyn uszkodzeń pod wpływem obciążeń zmęczeniowych,
Dozór Techniczny, ISSN: 0209-1763, Vol.4, pp.25-28, 2021 | |
5. |
Ustrzycka A., Mróz Z., Kowalewski Z.L., Kucharski S., Analysis of fatigue crack initiation in cyclic microplasticity regime,
INTERNATIONAL JOURNAL OF FATIGUE, ISSN: 0142-1123, DOI: 10.1016/j.ijfatigue.2019.105342, Vol.131, pp.105342-1-15, 2020Abstract: The present work provides description of fatigue crack initiation in metals subjected to cyclic loading within the nominal elastic or initial elastic-plastic regimes next passing to elastic response during cyclic deformation and shake down process. It is assumed that damage growth proceeds due to action of local stress, specified as the sum of mean stress and its fluctuations induced by material inhomogeneities such as grain boundaries, inclusions, cavities, boundary asperities, also due to design notches or holes introduced into the element. The damage growth model is proposed, based on the critical plane concept. The macrocrack initiation then corresponds to a critical value of accumulated damage. The modelling of damage growth is supported by Electronic Speckle Pattern Interferometry (ESPI) apparatus using the coherent laser light. The damage growth effect is analysed by microindentation tests. The fatigue tests are performed for high strength steel specimens with central hole. Keywords: fatigue crack initiation, micro-plasticity, damage evolution, optical ESPI method, micro indentation Affiliations:
Ustrzycka A. | - | IPPT PAN | Mróz Z. | - | IPPT PAN | Kowalewski Z.L. | - | IPPT PAN | Kucharski S. | - | IPPT PAN |
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6. |
Ustrzycka A., Skoczeń B.^{♦}, Nowak M., Kurpaska Ł.^{♦}, Wyszkowska E.^{♦}, Jagielski J.^{♦}, Elastic–plastic-damage model of nano-indentation of the ion-irradiated 6061 aluminium alloy,
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS, ISSN: 1056-7895, DOI: 10.1177/1056789520906209, pp.1-35, 2020Abstract: The paper presents experimental and numerical characterization of damage evolution for ion-irradiated materials subjected to plastic deformation during nano-indentation. Ion irradiation technique belongs to the methods where creation of radiation-induced defects is controlled with a high accuracy (including both, concentration and depth distribution control), and allows to obtain materials having a wide range of damage level, usually expressed in terms of displacements per atom (dpa) scale. Ion affected layers are usually thin, typically less than 1 micrometer thick. Such a low thickness requires to use nano-indentation technique to measure the mechanical properties of the irradiated layers. The He or Ar ion penetration depth reaches approximately 150 nm, which is sufficient to perform several loading-partial-unloading cycles at increasing forces. Damage evolution is reflected by the force-displacement diagram, that is backed by the stress–strain relation including damage. In this work the following approach is applied: dpa is obtained from physics (irradiation mechanisms), afterwards, the radiation-induced damage is defined in the framework of continuum damage mechanics to solve the problem of further evolution of damage fields under mechanical loads. The nature of radiation-induced damage is close to porosity because of formation of clusters of vacancies. The new mathematical relation between radiation damage (dpa) and porosity parameter is proposed. Deformation process experienced by the ion irradiated materials during the nano-indentation test is then numerically simulated by using extended Gurson–Tvergaard– Needleman (GTN) model, that accounts for the damage effects. The corresponding numerical results are validated by means of the experimental measurements. It turns out, that the GTN model quite successfully reflects closure of voids, and increase of material density during the nano-indentation. Keywords: radiation-induced damage, evolution of vacancy clusters, nano-indentation test, ion irradiation, radiation hardening Affiliations:
Ustrzycka A. | - | IPPT PAN | Skoczeń B. | - | Cracow University of Technology (PL) | Nowak M. | - | IPPT PAN | Kurpaska Ł. | - | National Centre for Nuclear Research (PL) | Wyszkowska E. | - | National Centre for Nuclear Research (PL) | Jagielski J. | - | National Centre for Nuclear Research (PL) |
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7. |
Ustrzycka A., Szuwalski K.^{♦}, Annular rotating disks optimal with respect to mixed creep rupture,
JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.56.1.57, Vol.56, No.1, pp.57-69, 2018Abstract: Optimal shapes in the class of polynomial functions for rotating annular disks with respect to the mixed creep rupture time are found. Two effects leading to damage: diminishing of transversal dimensions and growth of micro-cracks are simultaneously taken into account. The first of them requires the finite strain analysis, the latter is described by Kachanov's evolution equation. Behaviour of the material is described by nonlinear Norton's law, generalized for true stresses and logarithmic strains, and the shape change law in form of similarity of true stresses and logarithmic strains deviators. For optimal shapes of the disk, changes of geometry and a continuity function are presented. The theoretical considerations based on the perception of the structural components as some highlighted objects with defined properties is presented Keywords: annular disk, mixed creep rupture, optimal design Affiliations:
Ustrzycka A. | - | IPPT PAN | Szuwalski K. | - | Cracow University of Technology (PL) |
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8. |
Ustrzycka A., Mróz Z., Kowalewski Z.L., Experimental analysis and modelling of fatigue crack initiation mechanisms,
JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, DOI: 10.15632/jtam-pl.55.4.1443, Vol.55, No.4, pp.1443-1448, 2017Abstract: The present work is devoted to simulation of fatigue crack initiation for cyclic loading within the nominal elastic regime. It is assumed that damage growth occurs due to action of meanstress and its fluctuations induced by crystalline grain inhomogeneity and the free boundary effect. The macrocrack initiation corresponds to a critical value of accumulated damage. The modelling of damage growth is supported by Electronic Speckle Pattern Interferometry (ESPI) apparatus using coherent laser light. Keywords: fatigue crack initiation, damage evolution, optical methods Affiliations:
Ustrzycka A. | - | IPPT PAN | Mróz Z. | - | IPPT PAN | Kowalewski Z.L. | - | IPPT PAN |
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9. |
Skoczeń B.^{♦}, Ustrzycka A.^{♦}, Kinetics of evolution of radiation induced micro-damage in ductile materials subjected to time-dependent stresses,
International Journal of Plasticity, ISSN: 0749-6419, DOI: 10.1016/j.ijplas.2016.01.006, Vol.80, pp.86-110, 2016Abstract: The present paper aims at predicting evolution of radiation induced damage in the solids subjected to mechanical loads beyond the yield stress. Moreover, the evolution of radiation induced damage is combined with the evolution of mechanically induced damage within the common framework of Continuum Damage Mechanics (CDM). An additive formulation with respect to damage parameters (tensors) has been postulated. Multiscale constitutive model containing strong physical background related to the mechanism of generation of clusters of voids in the irradiated solids has been built. The model is based on the experimental estimation of concentration of lattice defects (interstitials, di-interstitials, interstitial clusters, vacancies, di-vacancies, vacancy clusters) in Al as a function of dpa (displacement per atom), and comprises the relevant kinetics of evolution of radiation induced damage under mechanical loads. Two kinetic laws of damage evolution were taken into account: the Rice & Tracey model and – for comparison – the Gurson model. As an application, estimation of lifetime of a cylindrical shell (coaxial target embedded in a detector of particles) subjected to combination of irradiation and mechanical loads, has been carried out. It is demonstrated that the number of cycles to failure depends strongly on the accumulation of micro-damage due to irradiation. The lifetime of irradiated components has been expressed as a function of two parameters: maximum dpa and axial stress amplitude on cycle. Affiliations:
Skoczeń B. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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10. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, Mathematical and numerical modelling of large creep deformations for annular rotating disks,
APPLIED MATHEMATICS AND MECHANICS-ENGLISH EDITION, ISSN: 0253-4827, DOI: 10.1007/s10483-015-1994-7, Vol.36, No.11, pp.1441-1448, 2015Abstract: A simulation model is presented for the creep process of the rotating disks under the radial pressure in the presence of body forces. The finite strain theory is applied. The material is described by the Norton-Bailey law generalized for true stresses and logarithmic strains. A mathematical model is formulated in the form of a set of four partial differential equations with respect to the radial coordinate and time. Necessary initial and boundary conditions are also given. To make the model complete, a numerical procedure is proposed. The given example shows the effectiveness of this procedure. The results show that the classical finite element method cannot be used here because both the geometry and the loading (body forces) change with the time in the creep process, and the finite elements need to be redefined at each time step. Keywords: creep process, rotating disk, finite strain theory, simulation model Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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11. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, Mathematical and numerical modelling of large axisymmetric creep strains and damage,
APPLIED MECHANICS AND MATERIALS, ISSN: 1662-7482, DOI: 10.4028/www.scientific.net/AMM.784.241, Vol.784, pp.214-248, 2015Abstract: The paper presents a simulation model for the creep process of rotating disks under radial tensional pressure subjected to of body force. The finite strain theory is applied. The material is described by the Norton - Bailey law generalized for true stresses and logarithmic strains. The mathematical model is formulated in form of set of four partial differential equations with respect to radial coordinate and time. Necessary initial and boundary conditions are also given. To make the model complete, the numerical procedure for solving this set is proposed. What is worth noticing the classical F EM is not applicable, because not only geometry, but also loading (body forces) change in time during the creep process. It would demand redefinition of finite elements at each time step. In uniaxial problem similar model was presented in [ 4 ], but now it is developed for complex stress state. Possible different formulations of initial and boundary conditions may be found in [ 5 ]. The procedure may be useful in problems of optimal design of full disks in [ 6 ] Keywords: creep process, rotating disks, finite strain theory, simulation model Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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12. |
Baussan E.^{♦}, Bielski J.^{♦}, Bobeth C.^{♦}, Bouquerel E.^{♦}, Caretta O.^{♦}, Cupial P.^{♦}, Davenne T.^{♦}, Densham C.^{♦}, Dracos M.^{♦}, Fitton M.^{♦}, Gaudiot G.^{♦}, Kozien M.^{♦}, Lacny L.^{♦}, Lepers B.^{♦}, Longhin A.^{♦}, Loveridge P.^{♦}, Osswald F.^{♦}, Poussot P.^{♦}, Rooney M.^{♦}, Skoczeń B.^{♦}, Szybinski B.^{♦}, Ustrzycka A.^{♦}, Vassilopoulos N.^{♦}, Wilcox D.^{♦}, Wroblewski A.^{♦}, Wurtz J.^{♦}, Zeter V.^{♦}, Zito M.^{♦}, Neutrino super beam based on a superconducting proton linac,
PHYSICAL REVIEW SPECIAL TOPICS - ACCELERATORS AND BEAMS, ISSN: 1098-4402, DOI: 10.1103/PhysRevSTAB.17.031001, Vol.17, No.3, pp.031001-1-26, 2014Abstract: We present a new design study of the neutrino Super Beam based on the Superconducting Proton Linac at CERN. This beam is aimed at megaton mass physics, a large water Cherenkov detector, proposed for the Laboratoire Souterrain de Modane in France, with a baseline of 130 km. The aim of this proposed facility is to study CP violation in the neutrino sector. In the study reported here, we have developed the conceptual design of the neutrino beam, especially the target and the magnetic focusing device. Indeed, this beam presents several unprecedented challenges, related to the high primary proton beam power (4 MW), the high repetition rate (50 Hz), and the low kinetic energy of the protons (4.5 GeV). The design is completed by a study of all the main components of the system, starting from the transport system to guide the beam to the target up to the beam dump. This is the first complete study of a neutrino beam based on a pebble-bed target capable of standing the large heat deposition of MW class proton beams Affiliations:
Baussan E. | - | Université de Strasbourg (FR) | Bielski J. | - | Cracow University of Technology (PL) | Bobeth C. | - | Université de Strasbourg (FR) | Bouquerel E. | - | Université de Strasbourg (FR) | Caretta O. | - | STFC Rutherford Appleton Laboratory (GB) | Cupial P. | - | AGH University of Science and Technology (PL) | Davenne T. | - | STFC Rutherford Appleton Laboratory (GB) | Densham C. | - | STFC Rutherford Appleton Laboratory (GB) | Dracos M. | - | Université de Strasbourg (FR) | Fitton M. | - | STFC Rutherford Appleton Laboratory (GB) | Gaudiot G. | - | Université de Strasbourg (FR) | Kozien M. | - | Cracow University of Technology (PL) | Lacny L. | - | Cracow University of Technology (PL) | Lepers B. | - | Université de Strasbourg (FR) | Longhin A. | - | Irfu, CEA-Saclay (FR) | Loveridge P. | - | STFC Rutherford Appleton Laboratory (GB) | Osswald F. | - | Université de Strasbourg (FR) | Poussot P. | - | Université de Strasbourg (FR) | Rooney M. | - | STFC Rutherford Appleton Laboratory (GB) | Skoczeń B. | - | Cracow University of Technology (PL) | Szybinski B. | - | other affiliation | Ustrzycka A. | - | other affiliation | Vassilopoulos N. | - | Université de Strasbourg (FR) | Wilcox D. | - | STFC Rutherford Appleton Laboratory (GB) | Wroblewski A. | - | other affiliation | Wurtz J. | - | Université de Strasbourg (FR) | Zeter V. | - | Université de Strasbourg (FR) | Zito M. | - | Irfu, CEA-Saclay (FR) |
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13. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, Optimal design of full disks with respect to mixed creep rupture time,
ENGINEERING STRUCTURES, ISSN: 0141-0296, DOI: 10.1016/j.engstruct.2013.08.001, Vol.56, pp.1728-1734, 2013Abstract: The mixed creep rupture theory to the optimization problem for the complex stress state is used. The problem of optimal shape for the rotating full disk with respect to mixed rupture time is investigated. The mathematical model of mixed creep rupture is described by the system of five partial differential equations. Difficulty of the problem results from two types of nonlinearities: geometrical connected with the use of the finite strain theory and physical – the material is described by the Norton’s creep law, here generalized for true stresses and logarithmic strains. Additional time factor leads to subsequent complications. The parametric optimization describing the initial shape of the disk is applied. The obtained results are compared with the optimal disks with respect to ductile creep rupture time Keywords: Mixed creep rupture, Structural optimization, Full disk Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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14. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, The influence of boundary conditions on optimal shape of annular disk with respect to ductile creep rupture time,
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS, ISSN: 0997-7538, DOI: 10.1016/j.euromechsol.2012.05.006, Vol.37, pp.79-85, 2013Abstract: This article deals with the influence of boundary conditions on the optimal shape of a rotating, axisymmetric annular disk of given volume that maximizes the ductile creep rupture time. The finite strain theory and physical law in form of Norton's law generalized for true stresses and logarithmic strains are applied. The optimal shape is found using parametric optimization. The initial shape of the disk is defined by class of polynomial function. Keywords: Boundary conditions, Optimal design, Ductile creep rupture time, Annular disk Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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15. |
Edgecock T.R.^{♦}, Caretta O.^{♦}, Davenne T.^{♦}, Densam C.^{♦}, Fitton M.^{♦}, Kelliher D.^{♦}, Loveridge P.^{♦}, Machida S.^{♦}, Prior C.^{♦}, Rogers C.^{♦}, Rooney M.^{♦}, Thomason J.^{♦}, Wilcox D.^{♦}, Wildner E.^{♦}, Efthymiopoulos I.^{♦}, Garoby R.^{♦}, Gilardoni S.^{♦}, Hansen C.^{♦}, Benedetto E.^{♦}, Jensen E.^{♦}, Kosmicki A.^{♦}, Martini M.^{♦}, Osborne J.^{♦}, Prior G.^{♦}, Stora T.^{♦}, Melo Mendonca T.^{♦}, Vlachoudis V.^{♦}, Waaijer C.^{♦}, Cupial P.^{♦}, Chancé A.^{♦}, Longhin A.^{♦}, Payet J.^{♦}, Zito M.^{♦}, Baussan E.^{♦}, Bobeth C.^{♦}, Bouquerel E.^{♦}, Dracos M.^{♦}, Gaudiot G.^{♦}, Lepers B.^{♦}, Osswald F.^{♦}, Poussot P.^{♦}, Vassilopoulos N.^{♦}, Wurtz J.^{♦}, Zeter V.^{♦}, Bielski J.^{♦}, Kozien M.^{♦}, Lacny L.^{♦}, Skoczeń B.^{♦}, Szybinski B.^{♦}, Ustrzycka A.^{♦}, et al.^{♦}, High intensity neutrino oscillation facilities in Europe,
PHYSICAL REVIEW SPECIAL TOPICS - ACCELERATORS AND BEAMS, ISSN: 1098-4402, DOI: 10.1103/PhysRevSTAB.16.021002, Vol.16, No.2, pp.021002-1-18, 2013Abstract: The EUROnu project has studied three possible options for future, high intensity neutrino oscillation facilities in Europe. The first is a Super Beam, in which the neutrinos come from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYS water Cherenkov, located in the Fréjus tunnel. The second facility is the Neutrino Factory, in which the neutrinos come from the decay of μ+ and μ− beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detector at a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinos come from the decay of beta emitting isotopes, in particular He6 and Ne18, also stored in a ring. The far detector is also the MEMPHYS detector in the Fréjus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYS detector is built for astroparticle physics, the Super Beam also becomes very attractive Affiliations:
Edgecock T.R. | - | STFC Rutherford Appleton Laboratory (GB) | Caretta O. | - | STFC Rutherford Appleton Laboratory (GB) | Davenne T. | - | STFC Rutherford Appleton Laboratory (GB) | Densam C. | - | STFC Rutherford Appleton Laboratory (GB) | Fitton M. | - | STFC Rutherford Appleton Laboratory (GB) | Kelliher D. | - | STFC Rutherford Appleton Laboratory (GB) | Loveridge P. | - | STFC Rutherford Appleton Laboratory (GB) | Machida S. | - | STFC Rutherford Appleton Laboratory (GB) | Prior C. | - | STFC Rutherford Appleton Laboratory (GB) | Rogers C. | - | STFC Rutherford Appleton Laboratory (GB) | Rooney M. | - | STFC Rutherford Appleton Laboratory (GB) | Thomason J. | - | STFC Rutherford Appleton Laboratory (GB) | Wilcox D. | - | STFC Rutherford Appleton Laboratory (GB) | Wildner E. | - | CERN (CH) | Efthymiopoulos I. | - | CERN (CH) | Garoby R. | - | CERN (CH) | Gilardoni S. | - | CERN (CH) | Hansen C. | - | CERN (CH) | Benedetto E. | - | CERN (CH) | Jensen E. | - | CERN (CH) | Kosmicki A. | - | other affiliation | Martini M. | - | CERN (CH) | Osborne J. | - | CERN (CH) | Prior G. | - | CERN (CH) | Stora T. | - | CERN (CH) | Melo Mendonca T. | - | CERN (CH) | Vlachoudis V. | - | CERN (CH) | Waaijer C. | - | CERN (CH) | Cupial P. | - | AGH University of Science and Technology (PL) | Chancé A. | - | Irfu, CEA-Saclay (FR) | Longhin A. | - | Irfu, CEA-Saclay (FR) | Payet J. | - | Irfu, CEA-Saclay (FR) | Zito M. | - | Irfu, CEA-Saclay (FR) | Baussan E. | - | Université de Strasbourg (FR) | Bobeth C. | - | Université de Strasbourg (FR) | Bouquerel E. | - | Université de Strasbourg (FR) | Dracos M. | - | Université de Strasbourg (FR) | Gaudiot G. | - | Université de Strasbourg (FR) | Lepers B. | - | Université de Strasbourg (FR) | Osswald F. | - | Université de Strasbourg (FR) | Poussot P. | - | Université de Strasbourg (FR) | Vassilopoulos N. | - | Université de Strasbourg (FR) | Wurtz J. | - | Université de Strasbourg (FR) | Zeter V. | - | Université de Strasbourg (FR) | Bielski J. | - | Cracow University of Technology (PL) | Kozien M. | - | Cracow University of Technology (PL) | Lacny L. | - | Cracow University of Technology (PL) | Skoczeń B. | - | Cracow University of Technology (PL) | Szybinski B. | - | other affiliation | Ustrzycka A. | - | other affiliation | et al. | - | other affiliation |
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16. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, Optimal design of bars under nonuniform tension with respect to mixed creep rupture time,
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS, ISSN: 0020-7462, DOI: 10.1016/j.ijnonlinmec.2012.03.002, Vol.47, pp.55-60, 2012Abstract: The first attempt of finding of optimal shape for bars in presence of body forces with respect to mixed creep rupture is made. For given volume of the bar, distribution of initial cross-section, ensuring the longest life-time to mixed rupture is sought. The finite strain theory and physical law in form of Norton's law generalized for true stresses and logarithmic strains are applied. Using the method of parametric optimization, the best of linear and quadratic functions describing the initial shape of the bar are found. The shape of initial strength is corrected in a way leading to longer life-time. Results of both approaches are compared Keywords: Mixed rupture, Structural optimization, Nonhomogeneity Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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17. |
Ustrzycka A.^{♦}, Optimal design of parabolic disk with respect to ductile creep rupture time,
Czasopismo Techniczne. Mechanika, ISSN: 1897-6328, Vol.108, No.15, pp.123-134, 2011Abstract: Axisymmetric rotating disks optimal with respect to ductile creep rupture time are considered. Finite strain theory is applied. The material is describe d by the Norton-Bailey law generalized for true stresses and logarithmic strains. The set of four partial differential equations describes the creep conditions of parabolic disk. The optimal shape of the disk is found using parametric optimisation with two free parameters. The results are compared with disks of conical shape. Keywords: finite strain theory, annular disk, ductile creep rupture time, biparametric optimization Affiliations:
Ustrzycka A. | - | other affiliation |
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18. |
Szuwalski K.^{♦}, Ustrzycka A.^{♦}, Optimal Design of Conical Disk with Respect to Ductile Creep Rupture Time,
Czasopismo Techniczne. Mechanika, ISSN: 1897-6328, Vol.106, No.12, pp.85-95, 2009Abstract: This paper presents the problem of optimal design with respect to ductile creep rupture time for rotating disk. The material is described by the Norton–Bailey nonlinear creep law, here generalized for true stresses and logarithmic strains. For complex stress states, the law of similarity of deviators, combined with the Huber–Mises–Hencky hypothesis is applied. The set of four partial differential equations describes the creep conditions of annular disk. The optimal shape of the disk is found using parametric optimisation with one free parameter. The results are compared with disks of uniform thickness. Keywords: optimal design, annular disk, ductile creep rupture time Affiliations:
Szuwalski K. | - | Cracow University of Technology (PL) | Ustrzycka A. | - | other affiliation |
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19. |
Ustrzycka A.^{♦}, Próba interpretacji niskich chmur rodzaju Stratus na sodarogramie,
PRZEGLĄD GEOFIZYCZNY, ISSN: 0033-2135, Vol.3-4, pp.227-236, 2006 | |
20. |
Walczewski J.^{♦}, Ustrzycka A.^{♦}, Biometeorologiczne aspekty wysokich temperatur powietrza lata 2003 w Krakowie,
WIADOMOŚCI IMGW, ISSN: 1897-5143, Vol.28, pp.73-79, 2005 | |