Service Lifetime Prediction Of Solar Absorber Surfaces From Results Of Accelerated Ageing Tests

1989 ◽  
Author(s):  
M. G. Hutchins ◽  
P. R. Dolley ◽  
K. Gindele ◽  
M. Khol ◽  
U. Frei ◽  
...  
Keyword(s):  
Lifetime Prediction ◽  
Accelerated Ageing ◽  
Solar Absorber ◽  
Service Lifetime

scholarly journals Lifetime Prediction Methods for Degradable Polymeric Materials—A Short Review

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4507 ◽  
Author(s):  
Angelika Plota ◽  
Anna Masek
Keyword(s):  
Polymeric Materials ◽  
Short Review ◽  
Isoconversional Method ◽  
Lifetime Prediction ◽  
Accelerated Ageing ◽  
Radiation Chemical ◽  
Degradation Reactions ◽  
Wlf Model ◽  
Advanced Isoconversional Method ◽  
The Impact

The determination of the secure working life of polymeric materials is essential for their successful application in the packaging, medicine, engineering and consumer goods industries. An understanding of the chemical and physical changes in the structure of different polymers when exposed to long-term external factors (e.g., heat, ozone, oxygen, UV radiation, light radiation, chemical substances, water vapour) has provided a model for examining their ultimate lifetime by not only stabilization of the polymer, but also accelerating the degradation reactions. This paper presents an overview of the latest accounts on the impact of the most common environmental factors on the degradation processes of polymeric materials, and some examples of shelf life of rubber products are given. Additionally, the methods of lifetime prediction of degradable polymers using accelerated ageing tests and methods for extrapolation of data from induced thermal degradation are described: the Arrhenius model, time–temperature superposition (TTSP), the Williams–Landel–Ferry (WLF) model and 5 isoconversional approaches: Friedman’s, Ozawa–Flynn–Wall (OFW), the OFW method corrected by N. Sbirrazzuoli et al., the Kissinger–Akahira–Sunose (KAS) algorithm, and the advanced isoconversional method by S. Vyazovkin. Examples of applications in recent years are given.

Prognostic Tools for Lifetime Prediction of Aircraft Coatings: Paint Degradation

2010 ◽  
Vol 138 ◽  
pp. 137-149 ◽  
Author(s):  
John M. Colwell ◽  
Javaid H. Khan ◽  
Geoffrey Will ◽  
Kathryn E. Fairfull-Smith ◽  
Steven E. Bottle ◽  
...  
Keyword(s):  
Direct Analysis ◽  
Accelerated Ageing ◽  
Environment Monitoring ◽  
Military Aircraft ◽  
Service Lifetime ◽  
Analysis Technique ◽  
Ft Ir ◽  
Flexible Polyurethane ◽  
Fluorescence Spectrometer ◽  
Statistical Analysis Methods

A direct interrogation, portable analysis technique (portable FT-IR) and a novel environment-monitoring profluorescent sensor for studying aircraft coating degradation have been developed. For the direct interrogation approach, a standard military aircraft paint: 459-line Anzothane flexible polyurethane (lead free) has been used to illustrate a new potential field technique to evaluate coating service lifetime, portable FT-IR. This technique allows direct analysis of chemical changes within the degrading coatings and has the potential to evaluate service lifetime when coupled with advanced statistical analysis methods (chemometrics). The degradation environment monitoring sensors are embodied in a profluorescent environment-sensitive witness patch that may be analysed in-service by a field-deployable fluorescence spectrometer. Accelerated ageing for both the paint and the witness patches has been undertaken and their capabilities as aircraft paint degradation monitors assessed.

scholarly journals Modeling Outdoor Service Lifetime Prediction of PV Modules: Effects of Combined Climatic Stressors on PV Module Power Degradation

2019 ◽  
Vol 9 (4) ◽  
pp. 1105-1112 ◽  
Author(s):  
Ismail Kaaya ◽  
Michael Koehl ◽  
Amantin Panos Mehilli ◽  
Sidrach de Cardona Mariano ◽  
Karl Anders Weiss
Keyword(s):  
Lifetime Prediction ◽  
Pv Module ◽  
Service Lifetime ◽  
Pv Modules

Investigating Wear and Predicting Lifetime of the Roller Cavities for the Net-shape Blade Rolling

2021 ◽  
Author(s):  
Qichao Jin ◽  
Wenhu Wang ◽  
Ruisong Jiang ◽  
lei Guo
Keyword(s):  
Prediction Model ◽  
Rolling Process ◽  
Contact Load ◽  
Lifetime Prediction ◽  
Wear Model ◽  
Service Lifetime ◽  
Local Contact ◽  
Analysis Experiment ◽  
Accumulation Effect ◽  
The Impact

Abstract The die undergoing severe loads which induces inevitably wear in the pressure forming process, and the wear of die arouses obsessions about the die’s service lifetime. In order to obtain the geometrical shape transformation caused by wear and predict the service lifetime for a pair of rollers in net-shape blade rolling process, this paper quantified the distributions and evolutions of the local wear over roller cavities based on the local contact load responses, and predicted the lifetime which related to wear by a mathematical models. Firstly, the net-shape blade rolling process and the local contact load responses were summarized. Then, an improved wear model was provided based on the Archard formula, and the impact factors of the model was standardized by a regression analysis experiment. The transient wear distributions and evolutions over the roller cavities were enumerated, and the wear distribution for one rolling cycle was calculated based on wear accumulation effect. Finally, a lifetime prediction model was proposed to predict the service lifetime of the rollers according to the wear accumulation effect, and an experimental verification was carried out to validate the model. The results showed that the wear model and lifetime prediction model can be used for investigating the wear and lifetime prediction of the roller cavities for the net-shape blade rolling process.

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