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

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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

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