Papers by Author: David Tawfik

Abstract: The Australian Nuclear Science and Technology Organisation (ANSTO) has recently started commissioning the new Australian Research Reactor OPAL that has replaced the old HIFAR reactor in January 2007. At the first stage, the new reactor will provide neutrons to several neutron scattering instruments. Among them is the residual stress diffractometer Kowari that was designed to study engineering problems related to residual stresses as well as allow material science research using neutron diffraction. We give an update on the progress of the instrument’s installation and commissioning and present an example to illustrate how neutron diffraction can be used to obtain information about residual stresses in a flash butt welded plate.

Abstract: Neutron scattering using diffraction techniques is now recognised as the most precise and reliable method of mapping sub-surface residual stresses in materials and industrial devices. It was therefore decided to build the dedicated strain scanner KOWARI among the first suite of instruments for the new Australian Replacement Research Reactor OPAL. In order to support the new instrument and familiarize the Australian user community with the technique a „Neutrons for Engineering“ project has been established to provide a fully integrated residual stress service. To make use of the neutrons at Australias HIFAR reactor the existing three-axis spectrometer has been refurbished and modified to allow strain measurements. The Australian Strain Scanner (TASS) will operate until the new strain scanner becomes operational in 2006. Apart from giving an overview about the technique and properties of the new strain scanner we would like to present and discuss two case studies: a) residual-stresses obtained from a break-disc of a car and b) residual-stresses within a flash-butt welded plate cut out of a railway.