Coupled processes of deformation and long-term damage of layered materials under thermal loading

2011 ◽  
Vol 47 (2) ◽  
pp. 169-176 ◽  
Author(s):  
L. P. Khoroshun ◽  
E. N. Shikula
Keyword(s):  
Thermal Loading ◽  
Layered Materials ◽  
Coupled Processes

Dissolution kinetics of meta-torbernite under circum-neutral to alkaline conditions

2009 ◽  
Vol 6 (6) ◽  
pp. 551 ◽  
Author(s):  
Dawn M. Wellman ◽  
Bruce K. McNamara ◽  
Diana H. Bacon ◽  
Elsa A. Cordova ◽  
Ruby M. Ermi ◽  
...  
Keyword(s):  
Dissolution Kinetics ◽  
Coupled Processes ◽  
Effect Of Temperature ◽  
Subsurface Environments ◽  
Alkaline Conditions ◽  
Flow Through ◽  
Uranium Phosphate ◽  
The Stability ◽  
Kinetics Of

Environmental context. Uranium-phosphate minerals have been identified as a long-term controlling phase that limit the mobility of uranium to groundwater in many contaminated subsurface environments. Complex, coupled processes confound the ability to isolate the rates attributed to individual processes. Results of this investigation provide the necessary information to refine current prediction on the release and long-term fate of uranium in subsurface environments. Abstract. The purpose of this investigation was to conduct a series of single-pass flow-through (SPFT) tests to (1) quantify the effect of temperature (23–90°C) and pH (6–10) on meta-torbernite dissolution; (2) compare the dissolution of meta-torbernite to other autunite-group minerals; and (3) evaluate the effect of aqueous phosphate on the dissolution kinetics of meta-torbernite. Results presented here illustrate meta-torbernite dissolution rates increase by ~100× over the pH interval of 6 to 10, irrespective of temperature. The power law coefficient for meta-torbernite, η = 0.59 ± 0.07, is greater than that quantified for Ca-meta-autunite, η = 0.42 ± 0.12. This suggests the stability of meta-torbernite is greater than that of meta-autunite, which is reflected in the predicted stability constants. The rate equation for the dissolution of meta-torbernite as a function of aqueous phosphate concentration is log rdissol (mol m–2 s–1) = –4.7 × 10–13 + 4.1 × 10–10[PO43–].

Initial performance of the lower deck of the Centre Street Bridge, Calgary

2009 ◽  
Vol 36 (1) ◽  
pp. 50-62
Author(s):  
P. L. Shrive ◽  
T. G. Brown ◽  
J. P. Newhook ◽  
J. Kroman ◽  
G. S. Tadros ◽  
...  
Keyword(s):  
Thermal Loading ◽  
Monitoring Program ◽  
Initial Assessment ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Reinforcement Design ◽  
Lower Deck

An initial assessment program was implemented for the lower deck of the Centre Street Bridge in Calgary. The program was designed so that the short-term behaviour of both the glass fibre reinforced polymer (GFRP) and steel reinforcements used in the lower deck, and their respective spans, could be compared. The monitoring provided useful information for verifying GFRP reinforcement design performance, and also raised challenging questions as to how the spans actually behave under thermal loading. Results indicated very little difference in the performances of the spans or their reinforcements over the three year monitoring period. Instrumentation and data acquisition systems are described herein, and representative data are presented. This project allowed the authors to develop some guidance criteria vis-à-vis structural health monitoring (SHM) requirements. During the latter stages of the monitoring program, the lower deck monitoring system was considered for its potential as a long-term SHM program, but on evaluation was found to have features that made it unsuitable for SHM purposes.

scholarly journals Fatigue Damage Management According to Performance Based Maintenance (PBM) Concept

2021 ◽  
Author(s):  
Masayuki Kamaya
Keyword(s):  
Fatigue Life ◽  
Crack Growth ◽  
Thermal Loading ◽  
Water Environment ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Term Operation ◽  
Primary Water ◽  
Crack Growth Curve

Abstract A maintenance concept of performance based maintenance (PBM) has been proposed by the current author. According to the PBM concept, inspection results are considered in determining the next inspection schedule. In this study, this concept was applied to fatigue degradation for stainless steel components in the pressurized water reactor (PWR) primary water environment. It is possible to estimate the fatigue life for the PWR water environment from that obtained in an air environment and the parameter Fen, which represents the ratio of the fatigue life in the air and PWR water environments. It was shown that the fatigue life prediction using Fen can be replaced by the crack growth analysis using the growth rate for the PWR water environment. Then, the crack growth was predicted for a thermal loading assuming the growth occurred in the PWR water environment. It was shown that the duration until the next inspection could be optimized based on the inspection results together with the crack growth curve. A long term operation before the inspection resulted in a longer duration until the next inspection.

Use of Natural Analog and Modeling Studies to Constrain the Effects of Magmatic Activity on Long-Term Geologic Repositories

1994 ◽  
Vol 353 ◽  
Author(s):  
Greg A. Valentine ◽  
N. D. Rosenberg ◽  
B. M. Crowe ◽  
F. V. Perry
Keyword(s):  
Radioactive Waste ◽  
Volcanic Eruption ◽  
Thermal Loading ◽  
Yucca Mountain ◽  
Temporal Scale ◽  
Magmatic Activity ◽  
Radioactive Waste Repository ◽  
Natural Analog ◽  
Waste Repository

AbstractExamples of the application of natural-analog studies to the estimation of the consequences of a volcanic eruption penetrating a radioactive waste repository are given, including the criteria for analog selection and new data from ongoing studies. Examples of early modeling results focusing on the spatial and temporal scale of subsurface processes are also provided. All of these examples are taken from studies of the potential Yucca Mountain repository, Nevada, but similar approaches could be applied in other areas. In addition, studies of subsurface processes initiated by magmatic events serve as useful analogs for repository thermal loading studies.

Reliability Monitoring in Drilling Electronic Circuit Boards

1991 ◽  
Vol 113 (3) ◽  
pp. 263-267 ◽  
Author(s):  
H. Hocheng ◽  
C. L. Jiaa
Keyword(s):  
Thermal Loading ◽  
Electronic Circuit ◽  
Processing Technique ◽  
Circuit Board ◽  
Circuit Boards ◽  
Signal Processing Technique ◽  
Reliability Monitoring ◽  
Long Term Performance ◽  
Term Performance

The purpose of the current study is to provide a monitoring scheme for evaluating the reliability of drilling of electronic circuit board (ECB) made of FR4 composite materials. The ECB is a laminated mechanical structure. Delamination often occurs at the hole exit during drilling. The resulted delamination deteriorates the long-term performance of the ECB when subject to mechanical and/or thermal loading. Acoustic emission can monitor the extent of this damage. A linear relationship exists between the size of delamination and the energy level of emitted signal when the proposed signal processing technique is used. The results contribute to higher quality ECB’s and can be applied in the manufacturing stage in an automated manner.

Numerical Analysis on Surface Fractures in Two-Layered Materials Subjected to Thermal Loading

2007 ◽  
Vol 353-358 ◽  
pp. 913-916
Author(s):  
Lian Chong Li ◽  
Chun An Tang ◽  
Jun Xing ◽  
Zheng Zhao Liang ◽  
Wei Jiang ◽  
...  
Keyword(s):  
Thermal Loading ◽  
Thermal Stresses ◽  
Mechanical Damage ◽  
Layered Materials ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Coating Materials ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
Mesoscopic Level

With the knowledge of heterogeneous characteristics of thermal barrier coating materials at mesoscopic level, a coupled thermo-mechanical-damage (TMD Model) model was introduced and used to numerically quantify the thermal stresses and crack development of in thermal barrier coatings (TBCs) composite subjected to decreased temperatures. The effect of different surface precrack morphologies, such as precrack length and precrack density, on an interface crack subjected to thermal loading caused by a temperature change is presented. It provides us with a more sensible physical intuition and a more accurate mathematical for optimizing the design and the processing of ceramic coatings subjected to the coupled thermal-mechanical loading.

Long-Term Cycle Stability Enabled by the Incorporation of Ni into Li2MnO3 Phase in the Mn-Based Li-Rich Layered Materials

2021 ◽  
Vol 6 (2) ◽  
pp. 789-798
Author(s):  
Junghwa Lee ◽  
Yue Gong ◽  
Lin Gu ◽  
Byoungwoo Kang
Keyword(s):  
Layered Materials ◽  
Cycle Stability
Sign in / Sign up

Export Citation Format

Share Document