scholarly journals PRODUCT LIFE ASSESSMENT METHODOLOGY UNDER RADIATION EXPOSURE

2021 ◽  
Author(s):  
Konstantin Zolnikov ◽  
Svetlana Evdokimova ◽  
A. Yagodkin ◽  
Sergey Grechanyy ◽  
P. Parmon
Keyword(s):  
Service Life ◽  
Radiation Exposure ◽  
Experimental Evaluation ◽  
Outer Space ◽  
Life Assessment ◽  
Assessment Methodology ◽  
Structural Effects ◽  
Product Life ◽  
Radiation Conditions

The article proposes a method for calculating and experimental evaluation of the service life of products in the specified radiation conditions of outer space. The described method of estimating the resource of products takes into account the additive nature of ionization and structural effects in the specified radiation conditions of outer space. This method includes experimental and computa-tional stages.

scholarly journals The thermal history and stress state of a fresh steam-pipeline influencing its remaining service life

2011 ◽  
Vol 15 (3) ◽  
pp. 691-704 ◽  
Author(s):  
Gordana Bakic ◽  
Vera Sijacki-Zeravcic ◽  
Milos Djukic ◽  
Stevan Maksimovic ◽  
Dusan Plesinac ◽  
...  
Keyword(s):  
Service Life ◽  
Elevated Temperatures ◽  
Operating Temperature ◽  
Life Assessment ◽  
Temperature History ◽  
Significant Variable ◽  
Remaining Life ◽  
Pipe Bend ◽  
Steam Pipeline ◽  
Remaining Life Assessment

The service life of thick-walled power plant components exposed to creep, as is the case with pipelines of fresh- and re-heated steam, depend on the exhaustion rate of the material. Plant operation at elevated temperatures and at temperatures below designed temperatures all relates to the material exhaustion rate, thus complicating remaining life assessment, whereas the operating temperature variation is a most common cause in the mismatching of real service- and design life. Apart from temperature, the tube wall stress is a significant variable for remaining life assessment, whose calculation depends on the selected procedure, due to the complex pipeline configuration. In this paper, a remaining life assessment is performed according to the Larson-Miller parametric relation for a ?324?36 pipe bend element of a fresh steam-pipeline, made of steel class 1Cr0.3Mo0.25V, after 160 000 hours of operation. The temperature history of the pipeline, altogether with the pipe bend, is determined based on continuous temperature monitoring records. Compared results of remaining life assessment are displayed for monitored temperature records and for designed operating temperature in the same time period. The stress calculation in the pipe bend wall is performed by three methods that are usually applied so to emphasize the differences in the obtained results of remaining life assessment.

A survey of the cosmic radiation exposure of Air Canada pilots during maximum galactic radiation conditions in 2009

2013 ◽  
Vol 49 ◽  
pp. 103-108 ◽  
Author(s):  
L.G.I. Bennett ◽  
B.J. Lewis ◽  
B.H. Bennett ◽  
M.J. McCall ◽  
M. Bean ◽  
...  
Keyword(s):  
Radiation Exposure ◽  
Cosmic Radiation ◽  
Radiation Conditions ◽  
Galactic Radiation

scholarly journals Designing radiation protection for the scientific equipment complex of the Earth’s remote sensing spacecraft

2019 ◽  
Author(s):  
T.Sh. Kombaev ◽  
M.E. Artemov ◽  
I.V. Zefirov
Keyword(s):  
Radiation Protection ◽  
Radiation Resistance ◽  
Outer Space ◽  
Electronic Component ◽  
Operating Conditions ◽  
Absorbed Doses ◽  
Equipment Complex ◽  
Scientific Equipment ◽  
Radiation Conditions ◽  
Onboard Equipment

In the course of operation spacecrafts are exposed to ionizing radiation from outer space. The electronic component base (ECB) used in creating onboard radio-electronic equipment of universal space platforms does not always correspond to the external operating conditions in terms of radiation resistance for some spacecraft orbits due to a number of technical and/or economic reasons. One method to increase the radiation resistance of onboard equipment is to install additional mass protection in the form of screens on the whole equipment or local screens on individual critical radio and electronic components. The article describes the design of additional radiation protection of the geostationary spacecraft scientific equipment complex for adaptation to the radiation conditions of operation in orbits of the “Molniya” type. The solution of the problem involves several preliminary steps, namely: determining the radiation conditions for the spacecraft operation in the target orbit, estimating the local absorbed doses at the locations of the onboard equipment, estimating absorbed doses directly in the electronic component base of the equipment and analyzing the radiation resistance. Designing the radiation complex of scientific equipment was based on the values of the radiation resistance of the equipment and its components, as well as the calculated values of the local absorbed doses in the components

Proposal for a Total Fatigue Life Assessment Methodology That Predicts Fatigue Life From Defect Initiation to Through Wall Leak

2020 ◽  
Author(s):  
Joseph Batten ◽  
Chris Currie ◽  
Jonathan Mann ◽  
Andrew Morley
Keyword(s):  
Fatigue Life ◽  
Effective Strain ◽  
Strain Range ◽  
Assessment Methods ◽  
Life Assessment ◽  
Assessment Methodology ◽  
Traditional Assessment ◽  
Fatigue Life Assessment ◽  
Definition Of

Abstract Even with improvements to remove excessive conservatisms, current fatigue assessment approaches can result in high Cumulative Usage Factors (CUFs) for some analyses. In order to improve plant availability from these assessments and mitigate future changes to design codes, an improvement in understanding in this area is desirable. Hence the proposal for a Life Assessment Methodology (LAM) was created. The LAM is a concept for an approach based on modelling each stage of fatigue life to predict total fatigue life, as a means of minimising conservatism in an assessment, where necessary. It should also be capable of incorporating statistical methods to assign reliability figures to calculated plant lives. This paper describes the proposed definition of the LAM and how a proof of concept version of the LAM was developed to assess the Bettis Bechtel Stepped Pipe (BBSP) test. The results were presented with two seeded cases (fixed inputs) and a range of lives corresponding to associated Target Reliabilities (TRs). The Best Estimate (BE) and TR associated lives produced were based on using the latest methods available for calculating Fatigue Initiation (FI) and Fatigue Crack Growth (FCG), whereas the seeded Effective Strain Range (ESR) comparison case used current deterministic assessment methods. The results for the case study concluded that there is a benefit to pursuing the development of the LAM when compared to traditional assessment methods. It highlighted and quantified the conservatism present in traditional assessment methods for these cases as well as the need to understand the required TR for a specific component as this can have a large effect on the predicted life. With further refinements to the method, a more realistic and robust output of the total fatigue life distribution (for specific cases) would be obtained, which in turn would allow us to better quantify the conservatism associated with a TR.

scholarly journals Modeling the mechanical wear of the contact elements of pantograph during high-speed movement

2020 ◽  
Vol 157 ◽  
pp. 01022
Author(s):  
Victor Philippov ◽  
Alexandr Smerdin
Keyword(s):  
Service Life ◽  
High Speed ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Maximum Error ◽  
Life Assessment ◽  
Rolling Stock ◽  
Mechanical Wear ◽  
Wear Process ◽  
Mechanical Component

The use of contact elements with an extended service life is one of the most economical and least costly ways to ensure reliable, economical and environmentally friendly transmission of electricity to rolling stock. To evaluate the service life in OSTU, a methodology for conducting experimental studies of contact pairs of pantograph has been developed and successfully tested, involving bench tests for each pair of contact materials “contact insert - contact wire” in order to determine their optimal combination to reduce wear and increase service life. Assessment of the amount of wear and prediction of the life of the contact elements are made, including using mathematical modeling. The purpose of this article is to improve the mechanical component of the wear model of the contact elements of pantograph in high-speed conditions. The results of experimental studies and theoretical calculations of the mechanical wear of contact elements are presented. The analysis of the graphs allows us to conclude that it is possible to use an improved mathematical model for modeling the mechanical component of the wear process of the elements of contact pairs with a maximum error value of not more than 5%.

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