Analytical and exprerimental investigation of composite structures for static and seismic loands

Κυριακόπουλος, Παναγιώτης; Kyriakopoulos, Panagiotis

dc.contributor.author	Κυριακόπουλος, Παναγιώτης	el
dc.contributor.author	Kyriakopoulos, Panagiotis	en
dc.date.accessioned	2023-02-15T10:17:16Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/57143
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.24841
dc.rights	Default License
dc.subject	DELTABEAM	en
dc.subject	Shallow floor composite beams	en
dc.subject	Ductility	en
dc.subject	Robustness	en
dc.subject	Finite element analysis	en
dc.subject	Σύμμικτες δοκοί	el
dc.subject	Πλαστημότητα	el
dc.subject	Μέθοδος πεπερασμένων στοιχείων	el
dc.subject	Πειραματική διερεύνηση	el
dc.subject	Λεπτές δοκοί	el
dc.title	Analytical and exprerimental investigation of composite structures for static and seismic loands	en
dc.title	Αναλυτική και πειραματική διερεύνηση σύμμικτων κατασκευών υπό στατικά και σεισμικά φορτία	en
heal.type	doctoralThesis
heal.classification	Structural engineering	en
heal.classification	Composite structures	en
heal.dateAvailable	2024-02-14T22:00:00Z
heal.language	en
heal.access	embargo
heal.recordProvider	ntua	el
heal.publicationDate	2021
heal.abstract	In recent decades, a strong demand for efficient and economical structural elements is being observed. This demand led to an increase in the use of factory prefabricated elements, such as, e.g., concrete hollow core elements for slabs and composite steel beams and columns, which can be assembled on site. The use of standardized prefabricated elements concealed a higher quality standard associated with lower cost followed by a high degree of flexibility because of a wide range of possible combinations. The necessity for reduction of the floor height for high-rise buildings, namely, a reduction of the height between floors, without reducing the usable space, was anticipated in order to increase the total number of floors for a given overall building height. Thus, parallel with prefabricated construction, a “new” more advanced structural system was born; the shallow floor system. In the shallow floor system, the steel beam is placed within the thickness of the pre-cast concrete floor or the composite slab with profiled steel decks. This form of construction leads to a reduced clear building height and is, at the same time, beneficial for the building services that may run in any direction. In this system, also called slim or shallow floor, the decking elements are not supported on the upper flange of the steel member, as in traditional steel-concrete composite construction, but on the bottom plate. Thus, in the finished construction the steel members are fully or partially encased in the concrete slab. The relatively small amount of research work related to shallow floor beams subjected to extreme loads, such as earthquakes or column loss scenarios, together with the lack of any relevant design guidance in the Eurocodes, as well as the numerous possibilities and combinations of steel sections and shapes that can be used, indicates the need to investigate this topic more extensively. Existing research in the literature is solely related to the investigation of the flexural behavior of composite beams with asymmetric double-T steel profiles, while the imposed load/displacement test sequences correspond to normal loading conditions. However, there is a need to examine the robustness of shallow-floor composite beams with hollow steel cross-sections under extreme loading conditions, shedding light to important factors, such as the shear connection between steel and concrete parts or the degree of confinement of the steel cross-section in cases of encased concrete. This dissertation elaborates on experimental investigations on shallow floor beams, called Deltabeams, carried out at the Institute of Steel Structures of the National Technical University of Athens (NTUA). Deltabeam is a slim-floor composite beam which took its name by the Δ-shape of the hollow section steel beam, which is fully integrated into the concrete floor. The composite beam behaves as a steel beam at construction stages before the infilling concrete has reached the design strength. After the erection of the decking units on the outward ledges of the bottom plate, the beam is completely filled with concrete in situ through regularly spaced web openings, forming a composite element at service stage after concrete hardening. Furthermore, three-dimensional (3D) Finite element models were created and calibrated with the experimental results. The good correlation of the numerical predictions with the experimental results gives an excellent opportunity to shed more light by further numerical analyses on the issues that could not be measured or indicated in the tests carried out and, thus, assist to a better understanding of the overall behavior of these beams. Finally, Deltabeams were successfully used as simply supported beams for the seismic design of an office building. Comparison of the results with a second model made by conventional monolithic concrete frames revealed the beneficial effect of the shallow floor construction, since, because of the lower height of Deltabeams, there was space for more floors for the same overall building height.	en
heal.advisorName	Σπυράκος, Κωνσταντίνος	el
heal.advisorName	Spyrakos, Constantine	en
heal.committeeMemberName	Ermopoulos, Ioannis
heal.committeeMemberName	Zeris, Christos	en
heal.committeeMemberName	Gantes, Charalampos	en
heal.committeeMemberName	Thanopoulos, Pavlos	en
heal.committeeMemberName	Fragiadakis, Michalis	en
heal.committeeMemberName	Lagaros, Nikolaos	en
heal.committeeMemberName	Ερμόπουλος, Ιωάννης	el
heal.committeeMemberName	Ζέρης, Χρήστος	el
heal.committeeMemberName	Γαντές, Χαράλαμπος	el
heal.committeeMemberName	Θανόπουλος, Παύλος	el
heal.committeeMemberName	Φραγκιαδάκης, Μιχάλης	el
heal.committeeMemberName	Λαγαρός, Νικόλαος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Πολιτικών Μηχανικών. Τομέας Δομοστατικής. Εργαστήριο Αντισεισμικής Τεχνολογίας	el
heal.academicPublisherID	ntua
heal.numberOfPages	346 σ.	el
heal.fullTextAvailability	false