Crashworthiness response of thin-walled steel circular tubes under oblique loading

Karantza, Konstantina; Καραντζά, Κωνσταντίνα

dc.contributor.author	Karantza, Konstantina	en
dc.contributor.author	Καραντζά, Κωνσταντίνα	el
dc.date.accessioned	2022-07-01T09:03:46Z
dc.date.available	2022-07-01T09:03:46Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/55352
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.23050
dc.description	Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Εφαρμοσμένη Μηχανική”	el
dc.rights	Default License
dc.subject	Crashworthiness	en
dc.subject	Oblique collapse	en
dc.subject	Thin-walled tubes	en
dc.subject	Steel circular tubes	en
dc.subject	LS-DYNA	en
dc.subject	Κρουστική καταπόνηση	el
dc.subject	Λοξή κατάρρευση	el
dc.subject	Λεπτότοιχοι σωλήνες	el
dc.subject	Χαλύβδινοι κυκλικοί σωλήνες	el
dc.title	Crashworthiness response of thin-walled steel circular tubes under oblique loading	en
heal.type	masterThesis
heal.secondaryTitle	Ικανότητα απορρόφησης ενέργειας χαλύβδινων κυλινδρικών κελυφών έναντι λοξής φόρτισης	el
heal.classification	Mechanical engineering	en
heal.classification	Crashworthiness	en
heal.classification	Crushing mechanics	en
heal.classification	Μηχανολογία	el
heal.classification	Κρουστική καταπόνηση	el
heal.classification	Μηχανική των κρούσεων	el
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2022-02-18
heal.abstract	The aim of current master thesis is to investigate the behavior of thin-walled circular steel tubes subjected to both axial and oblique crushing in order to evaluate their crashworthiness efficiency. In order to assess the energy absorption capability and the occurred collapse mechanism both experimental tests and numerical finite element simulations are carried out providing the load-displacement curve and the main crashworthiness response parameters, while further different collapse states are captured during plastic deformation. Regarding the examined oblique crushing conditions, various loading angles lying from 3o to 11o are studied aiming to estimate their effect on the absorbed energy and the failure mode occurred during plastic collapse. At first, experimental compression tests are conducted in quasi-static conditions under a constant loading rate of 10 mm/min by adjusting properly the loading angle representing off-axis oblique crushing conditions. For each examined specimen, two compression tests are carried out in order to secure the reliability of experimental results. At next, numerical simulation are carried out in LS-Dyna software by developing the finite element models of the examined cases. The developed models are simulated in dynamic conditions by adjusting a crushing speed of 1 m/s. Tubular specimens are modelled via 4-node shell elements, while at each examined configuration by both experiments and simulations the bottom tube end was considered as fixedly supported. The experimental and the numerical results were firstly compared between each other to validate the created finite element models, while also both were taken into account in order to evaluate the crashworthiness efficiency of the examined structures and assess the loading angle effect on their response. Both experiments and simulations showed a sufficient agreement in both occurred collapse mechanism and crashworthiness response parameters. The highest crashworthiness efficiency revealed by the axially collapsed specimen, while oblique loading conditions reacted to lower energy absorption capacity for the examined tubes. In fact, as the loading angle gets higher, additional bending loads are introduced capable of causing local bending to the crushed structure decreasing significantly its energy absorption capacity. In subsequence, as the loading angle increases, both plastic collapse load and absorbed energy revealed a decrease which showed a significantly sharper drop for loading angles beyond 6o highlighting the last one as a critical oblique loading angle compared to the examined ones.	en
heal.advisorName	Manolakos, Dimitrios	en
heal.advisorName	Μανωλάκος, Δημήτριος	el
heal.committeeMemberName	Theotokoglou, Efstathios	en
heal.committeeMemberName	Θεοτόκογλου, Ευστάθιος	el
heal.committeeMemberName	Kontou, Evagelia	en
heal.committeeMemberName	Κοντού, Ευαγγελία	el
heal.committeeMemberName	Manolakos, Dimitrios	en
heal.committeeMemberName	Μανωλάκος, Δημήτριος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Εφαρμοσμένων Μαθηματικών και Φυσικών Επιστημών	el
heal.academicPublisherID	ntua
heal.numberOfPages	125 σ.	el
heal.fullTextAvailability	false