Praise enhancements to include general strain hardening exponents and mid-life residual stress and water chemistry changes (open access)

Praise enhancements to include general strain hardening exponents and mid-life residual stress and water chemistry changes

The purpose of this document is to describe some recent changes made to the PRAISE Code to provide some additional capabilities. The major changes are associated with the new capability to analyze cases where there is a mid-life change in residual stresses and/or water chemistry. Such changes have been proposed as a means of improving the reliability of BWR piping by reducing the oxygen content of the coolant (or other favorable chemistry changes) or altering the residual stresses near welds to provide a stress distribution less favorable to crack initiation and growth. Induction heating stress improvement (IHSI) and mechanical stress improvement process (MSIP) are considered, with the time at which the process is implemented defined by the user. As-welded residual stresses are considered to be present prior to the stress imrovement treatment. Improved pre- and post-processors were also developed and are described, which should be particularly useful to users of the PC version of PRAISE. In addition, improved J-integral solutions are incorporated that allow a treatment of general Ramberg-Osgood strain hardening, rather than the specific values of the strain hardening exponent included in earlier versions of the PRAISE Code. This document discusses only the new additions to the code and …
Date: June 7, 1990
Creator: unknown
System: The UNT Digital Library
Characterization of rocket propellant combustion products: Description of sampling and analysis methods for rocket exhaust characterization studies (open access)

Characterization of rocket propellant combustion products: Description of sampling and analysis methods for rocket exhaust characterization studies

A systematic approach has been developed and experimentally validated for the sampling and chemical characterization of the rocket motor exhaust generated from the firing of scaled down test motors at the US Army's Signature Characterization Facility (ASCF) at Redstone Arsenal in Huntsville, Alabama. The overall strategy was to sample and analyze major exhaust constituents in near real time, while performing off-site analyses of samples collected for the determination of trace constituents of the particulate and vapor phases. Initial interference studies were performed using atmospheric pressure burns of 1 g quantities of propellants in small chambers at Oak Ridge National Laboratory. Carbon monoxide and carbon dioxide were determined using non-dispersive infrared instrumentation. Hydrogen cyanide, hydrogen chloride, and ammonia determinations were made using ion selective electrode technology. Oxides of nitrogen were determined using chemiluminescence instrumentation. Airborne particulate mass concentration was determined using infrared forward scattering measurements and a tapered element oscillating microbalance, as well as conventional gravimetry. Particulate phase metals were determined by collection on Teflon membrane filters, followed by inductively coupled plasma and atomic absorption analysis. Particulate phase polynuclear aromatic hydrocarbons (PAH) and nitro-PAH were collected using high volume sampling on a two stage filter. Target species were extracted, and quantified …
Date: June 7, 1990
Creator: Jenkins, R.A.
System: The UNT Digital Library