Prefazione

This investigation employs 3-D nonlinear finite element analyses to conduct an extensive parametric evaluation of crack front stress triaxiality for deep notch SE(B) and C(T) specimens and shallow notch SE(B) specimens, with and without side grooves. Crack front conditions are characterized in terms of J-Q trajectories and the constraint scaling model for cleavage fracture toughness proposed previously by Dodds and Anderson. The 3-D computational results imply that a significantly less strict size/deformation limit, relative to the limits indicated by previous plane-strain computations, is needed to maintain small-scale yielding conditions at fracture by a stress- controlled, cleavage mechanism in deep notch SE(B) and C(T) specimens. Additional new results made available from the 3-D analyses also include revised {eta}-plastic factors for use in experimental studies to convert measured work quantities to thickness average and maximum (local) J-values over the crack front

Weibull stress analysis for an embedded crack in reactor pressure vessels under pressurized thermal shock

Key Engineering Materials385-387773-776KEMA

Probabilistic Modeling of Brittle Fracture Including 3-D Effects on Constraint Loss and Ductile Tearing

This study presents a probabilistic, 3-D framework to describe brittle fracture in structural components which incorporates weakest link statistics and a micromechanics model reflecting local damage of material. The Weibull stress (σw) emerges as a fracture parameter to define conditions leading to local material failure. This parameter is correlated with the macroscopic loading and used to describe overall fracture conditions in a cracked solid exhibiting both loss of constraint and stable crack growth prior to cleavage fracture. The paper also describes an application of the proposed framework to predict the measured geometry and ductile tearing effects on the statistical distribution of cleavage fracture toughness for an HSLA steel

Elastic-plastic crack driving force for tubular X-joints with mismatched welds

10.1016/j.engstruct.2005.03.013Engineering Structures2791419-1434ENST

Mode mixity for circular hollow section X joints with weld toe cracks

10.1115/1.1951771Journal of Offshore Mechanics and Arctic Engineering1273269-27

Mode mixity for tubular K-joints with weld toe cracks

10.1016/j.engfracmech.2006.01.014Engineering Fracture Mechanics73101321-1342EFME

Ductile tearing in part-through cracks: experiments and cell-model predictions

10.1016/S0013-7944(97)00174-4Engineering Fracture Mechanics596761-777EFME

Application of the NCSA Habanero tool for collaboration on structural integrity assessments

The Habanero software was developed by the National Center for Superconducting Applications at the University of Illinois, Urbana-Champaign, as a framework for the collaborative sharing of Java applications. The Habanero tool performs distributed communication of single-user, computer software interactions to a multiuser collaborative environment. An investigation was conducted to evaluate the capabilities of the Habanero tool in providing an Internet-based collaborative framework for researchers located at different sites and operating on different workstations. These collaborative sessions focused on the sharing of test data and analysis results from materials engineering areas (i.e., fracture mechanics and structural integrity evaluations) related to reactor pressure vessel safety research sponsored by the US Nuclear Regulatory Commission. This report defines collaborative-system requirements for engineering applications and provides an overview of collaborative systems within the project. The installation, application, and detailed evaluation of the performance of the Habanero collaborative tool are compared to those of another commercially available collaborative product. Recommendations are given for future work in collaborative communications

Application of the NCSA Habanero tool for collaboration on structural integrity assessments

The Habanero software was developed by the National Center for Superconducting Applications at the University of Illinois, Urbana-Champaign, as a framework for the collaborative sharing of Java applications. The Habanero tool performs distributed communication of single-user, computer software interactions to a multiuser collaborative environment. An investigation was conducted to evaluate the capabilities of the Habanero tool in providing an Internet-based collaborative framework for researchers located at different sites and operating on different workstations. These collaborative sessions focused on the sharing of test data and analysis results from materials engineering areas (i.e., fracture mechanics and structural integrity evaluations) related to reactor pressure vessel safety research sponsored by the US Nuclear Regulatory Commission. This report defines collaborative-system requirements for engineering applications and provides an overview of collaborative systems within the project. The installation, application, and detailed evaluation of the performance of the Habanero collaborative tool are compared to those of another commercially available collaborative product. Recommendations are given for future work in collaborative communications