Σχεδίαση συσκευής Kolsky τύπου συμπίεσης για τον έλεγχο δειγμάτων αλουμινίου

Ποθητός, Βασίλειος; Pothitos, Vasileios

dc.contributor.author	Ποθητός, Βασίλειος	el
dc.contributor.author	Pothitos, Vasileios	en
dc.date.accessioned	2016-09-30T06:41:39Z
dc.date.available	2016-09-30T06:41:39Z
dc.date.issued	2016-09-30
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/43692
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.3723
dc.description	Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Συστήματα Αυτοματισμού”	el
dc.rights	Default License
dc.subject	Split Hopkinson	en
dc.subject	Kolsky	en
dc.subject	Strain rate	en
dc.subject	Mechanical stress	en
dc.subject	Mechanical strain	en
dc.subject	Συμπιέση δείγματος	el
dc.subject	Παραμόρφωση δείγματος	el
dc.subject	Τάση δείγματος	el
dc.subject	Ράβδοι συμπίεσης	el
dc.subject	Όριο ελαστικότητας υλικού	el
dc.title	Σχεδίαση συσκευής Kolsky τύπου συμπίεσης για τον έλεγχο δειγμάτων αλουμινίου	el
heal.type	masterThesis
heal.classification	Mechanical engineering	el
heal.classificationURI	http://skos.um.es/unescothes/C02447
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2016-07-06
heal.abstract	Σχεδίαση συσκευής Kolsky (Split Hopkinson Bar), πρόταση διαδικασίας σχεδίασης με έλεγχο μέσω προσομοίωσης (Simulink), εφαρμογή για δείγματα αλουμινίου, δημιουργία μοντέλου CAD τελικής συσκευής	el
heal.abstract	The Kolsky bar apparatus (Split Hopkinson Bar) is the most widespread solution for testing materials, under conditions of heavy mechanical stress. Although the theory behind its functionality was firstly expressed at the beginning of the 20th century (Bertram Hopkinson, 1913) and formulated to its final form at the end of 1940s (Kolsky, 1949), meaningful progress towards its practical use was achieved for the first time during the end of 1960s, followed by rapid progression during the remaining decades of the 20th century and to this day. The reasons behind this progress, are the technological advancements in the field of electronics (computer hardware and software, able to handle more demanding data processing techniques, high precision sensors and measuring devices) but also the discovery of new, οr the improvement of existing, materials (alloys, multi-layered structures, plastics). For these materials, the knowledge of their behavior under conditions of heavy mechanical stress, is an essential factor of choice for specific constructions. A Kolsky bar apparatus consists of two long slender bars that sandwich a short cylindrical specimen between them. By striking the end of a bar (Incident Bar), a compressive stress wave is generated, that immediately begins to traverse towards the specimen. Upon arrival at the specimen, the wave partially reflects towards the impact end. The remainder of the wave transmits through the specimen and into the 2nd bar (Transmission Bar), causing irreversible plastic deformation in the specimen. The reflected wave is proportional to the specimen’s strain rate and the transmitted wave is proportional to the specimen’s mechanical stress. By monitoring the strains in the two bars, specimen stress-strain properties can be calculated. On this thesis, the design of a Kolsky Bar apparatus is approached. First, various methodologies and factors affecting the design are discussed. A step by step design model is proposed later, with a number of practical algorithms for the various design stages. This approach, is built upon simulations and theoretical calculations (Matlab/Simulink, C++). At the next stage, the model is used for the design of a Kolsky bar apparatus, for the calculation of Aluminum specimens’ stress-strain properties. Simulation results are presented and compared with those of actual tests, with real devices. After this, a solid modeling computer-aided design (CAD, Solidworks) of the device is created. The thesis concludes with a summarizing discussion of the results and proposals for further research, on how this method can be generalized and achieve better results.	en
heal.advisorName	Μανωλάκος, Δημήτριος	el
heal.committeeMemberName	Βοσνιάκος, Γεώργιος Χριστόφορος	el
heal.committeeMemberName	Αντωνιάδης, Αντώνιος	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Μηχανολόγων Μηχανικών	el
heal.academicPublisherID	ntua
heal.numberOfPages	220 σ.	el
heal.fullTextAvailability	true