{"id":{"repo_id":"greece","oai_identifier":"oai:10442/1695"},"canonical_url":"https://search.dev.ndltd.org/etd/greece/oai:10442/1695","repository":{"repo_id":"greece","name":"Greek National Archive of PhD Theses","base_url":"https://phdtheses.ekt.gr/eadd_oai/request"},"display":{"title":"Αστοχία ρηγματομένων όλκιμων πλακών με δύο συμμετρικές εγκοπές","abstract":"The objective of this dissertation is to study the interaction between a crack and two symmetrical edge notches perpendicular to the plane of the crack. Based on the strain energy density criterion the critical stress for crack growth initiation is determined. The influence of body geometry as it is dictated by notch radius, crack length and distance between crack and notches on the critical stress is studied and important results are established. Crack growth initiation followed by stable crack growth which is also studied by strain energy density criterion. The global minimum of the strain energy density in function from which the crack trajectory passes during unstable crack growth is also determined. The distance between this point and the crack tip plans an important role for the determination of the stability of the body with cracks. The smaller this distance the non stable the body.","abstract_html":"The objective of this dissertation is to study the interaction between a crack and two symmetrical edge notches perpendicular to the plane of the crack. Based on the strain energy density criterion the critical stress for crack growth initiation is determined. The influence of body geometry as it is dictated by notch radius, crack length and distance between crack and notches on the critical stress is studied and important results are established. Crack growth initiation followed by stable crack growth which is also studied by strain energy density criterion. The global minimum of the strain energy density in function from which the crack trajectory passes during unstable crack growth is also determined. The distance between this point and the crack tip plans an important role for the determination of the stability of the body with cracks. The smaller this distance the non stable the body.","abstract_has_math":false,"creators":["Thireos, C.","Θηραιός, Κωνσταντίνος"],"institution":"National Technical University of Athens (NTUA)","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1991,"date_issued":"1991","date_published":"1991","updated_at":"2026-07-24T02:25:05Z","subjects":["Εγκοπές","Ελαστοπλαστική συμπεριφορά","Έναρξη διάδοσης ρωγμής","Ευστάθεια σώματος","Ευσταθής και ασταθής διάδοση ρωγμής","Όλκιμη θραύση","Πεπερασμένα στοιχεία","Ρωγμές","Τροχιά διάδοσης ρωγμής","Crack","Crack trajectory","Crackgrowth initiation","Ductile fracture","Elastic-plastic behavior","Finite elements","Notches","Stability of a body","Stable and unstable crack growth","Επιστήμες Μηχανικού και Τεχνολογία","Μηχανική Υλικών","Engineering and Technology","Materials Engineering"],"languages":["gre"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1695"],"render_values":[{"text":"10.12681/eadd/1695","href":"https://doi.org/10.12681/eadd/1695","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10442/hedi/1695","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Thireos, C.","Θηραιός, Κωνσταντίνος"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1991"]},{"key":"dc:publisher","label":"Institution","values":["National Technical University of Athens (NTUA)","Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)"]},{"key":"dc:type","label":"Dc Type","values":["PhD Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Εγκοπές","Ελαστοπλαστική συμπεριφορά","Έναρξη διάδοσης ρωγμής","Ευστάθεια σώματος","Ευσταθής και ασταθής διάδοση ρωγμής","Όλκιμη θραύση","Πεπερασμένα στοιχεία","Ρωγμές","Τροχιά διάδοσης ρωγμής","Crack","Crack trajectory","Crackgrowth initiation","Ductile fracture","Elastic-plastic behavior","Finite elements","Notches","Stability of a body","Stable and unstable crack growth","Επιστήμες Μηχανικού και Τεχνολογία","Μηχανική Υλικών","Engineering and Technology","Materials Engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["gre"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.12681/eadd/1695","http://hdl.handle.net/10442/hedi/1695"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The objective of this dissertation is to study the interaction between a crack and two symmetrical edge notches perpendicular to the plane of the crack. Based on the strain energy density criterion the critical stress for crack growth initiation is determined. The influence of body geometry as it is dictated by notch radius, crack length and distance between crack and notches on the critical stress is studied and important results are established. Crack growth initiation followed by stable crack growth which is also studied by strain energy density criterion. The global minimum of the strain energy density in function from which the crack trajectory passes during unstable crack growth is also determined. The distance between this point and the crack tip plans an important role for the determination of the stability of the body with cracks. The smaller this distance the non stable the body.","Αντικείμενο της διατριβής αυτής αποτελεί η μελέτη της αλληλεπίδρασης μιας ρωγμής και δύο ακραίων συμμετρικών εγκοπών εντός επιπέδου σώματος το οποίο υπόκειται εφελκυστικό φορτίο κάθετο στο επίπεδο της ρωγμής. Βασιζόμενοι στο κριτήριο της πυκνότητας της ενέργειας παραμόρφωσης υπολογίζεται το κρίσιμο φορτίο έναρξης διάδοσης της ρωγμής. Εξετάζεται η επίδραση της γεωμετρίας του επιπέδου σώματος, όπως αυτή καθορίζεται από την ακτίνα των εγκοπών, το μήκος των ρωγμών και την απόσταση ρωγμής-εγκοπής επί του κρίσιμου φορτίου και συνάγονται σημαντικά συμπεράσματα. Της ενάρξεως διαδόσεως της ρωγμής ακολουθεί το κριτήριο της πυκνότητας της ενέργειας παραμόρφωσης. Υπολογίζεται επιπλέον η θέση του ελαχίστου της πυκνότητας της ενέργειας παραμόρφωσης στο σώμα, σημείο διάδοσης της. Η απόσταση μεταξύ του σημείου αυτού και του άκρου της ρωγμής παίζει σημαντικό ρόλο, για τον καθορισμό της ευστάθειας του σώματος με ρωγμή. Όσο μικρότερη είναι η απόσταση αυτή τόσο πιο ευσταθές είναι το σύστημα."]},{"key":"dc:title","label":"Title","values":["Αστοχία ρηγματομένων όλκιμων πλακών με δύο συμμετρικές εγκοπές","Failure of cracked ductile plates containing two symmetric notches"]}]}],"canonical_facts":{"dc:creator":["Thireos, C.","Θηραιός, Κωνσταντίνος"],"dc:date":["1991"],"dc:description":["The objective of this dissertation is to study the interaction between a crack and two symmetrical edge notches perpendicular to the plane of the crack. Based on the strain energy density criterion the critical stress for crack growth initiation is determined. The influence of body geometry as it is dictated by notch radius, crack length and distance between crack and notches on the critical stress is studied and important results are established. Crack growth initiation followed by stable crack growth which is also studied by strain energy density criterion. The global minimum of the strain energy density in function from which the crack trajectory passes during unstable crack growth is also determined. The distance between this point and the crack tip plans an important role for the determination of the stability of the body with cracks. The smaller this distance the non stable the body.","Αντικείμενο της διατριβής αυτής αποτελεί η μελέτη της αλληλεπίδρασης μιας ρωγμής και δύο ακραίων συμμετρικών εγκοπών εντός επιπέδου σώματος το οποίο υπόκειται εφελκυστικό φορτίο κάθετο στο επίπεδο της ρωγμής. Βασιζόμενοι στο κριτήριο της πυκνότητας της ενέργειας παραμόρφωσης υπολογίζεται το κρίσιμο φορτίο έναρξης διάδοσης της ρωγμής. Εξετάζεται η επίδραση της γεωμετρίας του επιπέδου σώματος, όπως αυτή καθορίζεται από την ακτίνα των εγκοπών, το μήκος των ρωγμών και την απόσταση ρωγμής-εγκοπής επί του κρίσιμου φορτίου και συνάγονται σημαντικά συμπεράσματα. Της ενάρξεως διαδόσεως της ρωγμής ακολουθεί το κριτήριο της πυκνότητας της ενέργειας παραμόρφωσης. Υπολογίζεται επιπλέον η θέση του ελαχίστου της πυκνότητας της ενέργειας παραμόρφωσης στο σώμα, σημείο διάδοσης της. Η απόσταση μεταξύ του σημείου αυτού και του άκρου της ρωγμής παίζει σημαντικό ρόλο, για τον καθορισμό της ευστάθειας του σώματος με ρωγμή. Όσο μικρότερη είναι η απόσταση αυτή τόσο πιο ευσταθές είναι το σύστημα."],"dc:identifier":["10.12681/eadd/1695","http://hdl.handle.net/10442/hedi/1695"],"dc:language":["gre"],"dc:publisher":["National Technical University of Athens (NTUA)","Εθνικό Μετσόβιο Πολυτεχνείο (ΕΜΠ)"],"dc:subject":["Εγκοπές","Ελαστοπλαστική συμπεριφορά","Έναρξη διάδοσης ρωγμής","Ευστάθεια σώματος","Ευσταθής και ασταθής διάδοση ρωγμής","Όλκιμη θραύση","Πεπερασμένα στοιχεία","Ρωγμές","Τροχιά διάδοσης ρωγμής","Crack","Crack trajectory","Crackgrowth initiation","Ductile fracture","Elastic-plastic behavior","Finite elements","Notches","Stability of a body","Stable and unstable crack growth","Επιστήμες Μηχανικού και Τεχνολογία","Μηχανική Υλικών","Engineering and Technology","Materials Engineering"],"dc:title":["Αστοχία ρηγματομένων όλκιμων πλακών με δύο συμμετρικές εγκοπές","Failure of cracked ductile plates containing two symmetric notches"],"dc:type":["PhD Thesis"]},"updated_at":"2026-07-24T02:25:05Z"}