Measurement of Creep Deformation across Welds in 316H Stainless Steel Using Digital Image Correlation

Spatially resolved measurement of creep deformation across weldments at high temperature cannot be achieved using standard extensometry approaches. In this investigation, a Digital Image Correlation (DIC) based system has been developed for long-term high-temperature creep strain measurement in order to characterise the material deformation behaviour of separate regions of a multi-pass weld. The optical system was sufficiently stable to allow a sequence of photographs to be taken suitable for DIC analysis of creep specimens tested at a temperature of 545 °C for over 2000 h. The images were analysed to produce local creep deformation curves from two cross-weld samples cut from contrasting regions of a multi-pass V-groove weld joining thick-section AISI Type 316H austenitic stainless steel. It is shown that for this weld, the root pass is the weakest region of the structure in creep, most likely due to the large number of thermal cycles it has experienced during the fabrication process. The DIC based measurement method offers improved spatial resolution over conventional methods and greatly reduces the amount of material required for creep characterisation of weldments

OnLine Compression of High Precision Printer Images by Evolvable Hardware

This paper describes an image compression system based on Evolvable HardWare (EHW) for High Precision Printers (HPP). These printers are especially flexible for book publishing, but require large disk space for images, in particular those of higher resolution. To increase the printing speed and reduce the disk space, the images should be compressed. The system for this compression must be 1) adaptive, so that it changes depending on image characteristics and 2) on-line, which means implemented in hardware. The standard compression methods have a simple template change strategy which is not efficient for the images of HPP. We used an EHW system for compressing HPP images in real time. The EHW is a type of adaptive hardware which allows evolutionary algorithms to change the hardware configuration in real time. It works as fast as other compression systems (like JBIG standard), but changes the image modeling to reflect the changes in the image characteristics. Simulation results show more than a 50 % increase in compression ratio compared to JBIG for the printer system. 1

Response of the GAGG(Ce) scintillator to charged particles compared with the CsI(Tl) scintillator

This is the Accepted Manuscript version of an article accepted for publication in Journal of Instrumentation. IOP Publishing Ltd are not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1748-0221/16/10/P10012