Robust estimation of fracture parameters

Wu, Shaojun (1996) Robust estimation of fracture parameters. Doctoral (PhD) thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (4MB)

Abstract

Fracture mechanics is mainly concerned with the analysis of fracture-dominant failure. Various methods of analyses for cracks are used in the determination of fracture characterizing parameters, which in turn can be used to predict loads and crack sizes at which failure would occur. -- In engineering practice, robust methods for estimating fracture parameters are useful, given the lack of details of material data, geometric configuration and computational sophistication in an operational industrial plant. This thesis focuses on the approximate methods for the determination of (1) crack tip plastic zone size, (2) the J of circular-ended notches and (3) the J for three-dimensional pressure vessels and piping components. Furthermore, this thesis focuses on design perspectives based on robust methods. -- The assessment of the integrity of structures and components with defects has been shown to be possible using the robust methods developed in this thesis. The robust method for estimating the elastic-plastic energy release rate has been presented which is suitable for the purpose of design. In order to estimate the effect of out-of-plane loading which is parallel to the crack front, the so-called "2½-D" model is proposed in this thesis. This model has been developed to evaluate J for three-dimensional pressure vessels and piping components with defects such as pressure vessels and piping with a circumferential flaw or a longitudinal flaw.

Actions (login required)

View Item