Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.331734
Title: Ductile fracture mechanisms in a structural steel
Author: Shi, Yao-Wu
Awarding Body: University of Aston in Birmingham
Current Institution: Aston University
Date of Award: 1982
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Abstract:
Microstructural fracture processes in a BS4360 Grade 50D structural steel with lower sulphur content were studied in smooth tensile specimen tests and Charpy-size bend bar tests. Based on the experimental analysis, an experimental void growth relation with the plastic strain and stress triaxiality and multiplying factor on void growth were determined. Experimental results show that the void growth relation can be reasonably used to estimate the constraint in the specimens containing the notch or crack, also they can be used to evaluate the variations of the stress triaxiality in front of the notch and crack tip under general yielding condition. Side-grooves obviously increase the constraint of the CVN specimens. Strain hardening leads to increasing the stress triaxiality, and decelerating the net void growth. This is especially true for the values of stress triaxiality more than about one. Additionally, the effect of the stress triaxiality on the critical void growth corresponding to the onset of ductile tearing was preliminarily investigated. In this work, a large number of smaller specimens were tested to investigate the ductile-brittle transition behaviour of the structural steel. A void growth rate explanation was suggested for evaluating the temperature transition behaviour. The elastic-plastic fracture tough-ness values based on small specimen tests, such as pre-cracked side-grooved bending specimen and short bar tensile specimen, may give large overestimates of the plane strain fracture toughness.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.331734  DOI: Not available
Keywords: Engineering Materials ; Metallurgy
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