1. Αποθετήριο Παραδοτέων Υποτρόφων Δράσεων ΕΣΠΑ Τριτοβάθμιας Εκπαίδευσης 2017-2023
2. Όλο το Αποθετήριο
3. Ερευνητικές ομάδες

Τύπος:	Ανακοίνωση σε συνέδριο
Τίτλος:	Non-linear homogenization theories with applications to trip steels
Συγγραφέας:	[EL] Παπαδιώτη, Ιωάννα[EN] Papadioti, Ioanna [EL] Μπέλλας, Ηλίας[EN] Bellas, Ilias [EL] Τζίνη, Μαρία - Ιωάννα[EN] Tzini, Maria Ioanna [EL] Χριστοδούλου, Πέτρος[EN] Christodoulou, Peter [EL] Άραβας, Νικόλαος[EN] Aravas, Nikolaos
Ημερομηνία:	04/06/2018
Περίληψη:	A general constitutive model for N−phase isotropic, incompressible, rate-independent elasto-plastic composite materials at finite strains is developed. The formulation is based on the non-linear homogenization variational (or modified secant) method which makes use of a linear comparison composite (LCC) material to estimate the effective flow stress of the non-linear composite material. The homogenization approach leads to an algebraic optimization problem, which for a two-phase material (N=2) is solved analytically, whereas for N>3 the solution is obtained numerically. The model is validated by periodic three-dimensional unit cell calculations comprising a large number of spherical inclusions distributed randomly in a matrix phase. The homogenization technique provides accurate estimates not only for the effective flow stress but also for the average strains in the constituent phases. These estimates form the basis for the development of an approximate analytical model for the elastoplastic behavior of a composite with hardening phases. The predictions of the model are in excellent agreement with the results of detailed unit cell finite element calculations of a composite with hardening phases for different types of loadings, including uniaxial tension and finite shear. The homogenization theory is also used to develop a constitutive model for the mechanical behavior of TRIP (TRansformation Induced Plasticity) steels. TRIP steels are essentially composite materials with evolving volume fractions of the constituent phases. The calibration of the model is based on uniaxial tension tests on TRIP steels. The constitutive model is used for the calculation of “Forming Limit Diagrams” (FLDs) for sheets made of TRIP steels; it is found that the TRIP phenomenon increases the strain at which local necking results from a gradual localization of the strains at an initial thickness imperfection in the sheet.
Γλώσσα:	Αγγλικά
Τόπος δημοσίευσης:	Chania, Crete, Greece
Σελίδες:	10
ISBN:	978-618-81537-5-2
Θεματική κατηγορία:	[EL] Επιστήμες Μηχανικού και Τεχνολογία[EN] Engineering and Technology
Λέξεις-κλειδιά:	homogenization; elasto-plasticity; composite materials; Finite strains; TRIP steels
Κάτοχος πνευματικών δικαιωμάτων:	© by the authors.
Διατίθεται ανοιχτά στην τοποθεσία:	https://dias.library.tuc.gr/view/78635
Τίτλος πηγής δημοσίευσης:	9th GRACM International Congress on Computational Mechanics Book of Full-length Papers
Σελίδες τεκμηρίου (στην πηγή):	284-293
Όνομα εκδήλωσης:	9th GRACM International Congress on Computational Mechanics
Τοποθεσία εκδήλωσης:	Chania, Crete, Greece
Ημ/νία έναρξης εκδήλωσης:	04/06/2018
Ημ/νία λήξης εκδήλωσης:	06/06/2018
Σημειώσεις:	Book of abstracts eds. M. Papadrakakis and G.E. Stavroulakis, Technical University of Crete Press, Chania, 2018 ISBN 978-618-81537-4-5, ISBN 978-618-81537-5-2 The book of abstracts and the book of full-length papers have been published by the Technical University of Crete Press. Both are available at the repository of the University Library https://dias.library.tuc.gr/view/78632 (Book of Abstracts) - https://dias.library.tuc.gr/view/78635 (Book of Papers) This work was carried out in the framework of “TRIP steels: Simulation and experimental study of heat treatment and mechanical behavior” project. This research is implemented through the Operational Program "Human Resources Development, Education and Lifelong Learning" and is co-financed by the European Union (European Social Fund) and Greek national funds
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