Life Prediction for Anticorrosive Coatings on Steel Bridges

CORROSION ◽  
10.5006/3504 ◽  
2020 ◽  
Vol 76 (8) ◽  
pp. 773-785
Author(s):  
Zehui Zhang ◽  
Jin Wu ◽  
Tian Su ◽  
Xiangkun Mo ◽  
Huachao Deng ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Prediction Model ◽  
Life Prediction ◽  
Test Site ◽  
Steel Bridge ◽  
Exposure Test ◽  
Anticorrosive Coatings ◽  
Natural Exposure ◽  
Stress Coefficient ◽  
Life Prediction Model

This paper presents the results of the effects of tensile stress and corrosion environment on the performances of epoxy (EP) coating systems and fluorocarbon (FC) coating systems on steel bridge by accelerated exposure test. Gloss, color characteristic parameter, and blistering area were selected to be aging indexes of anticorrosive coatings. Four different stress levels were applied on coated steel panel specimens by using a three-point bend loading, and the stress coefficient is proposed in this paper. The results showed that coating corroded more severely in seawater than in freshwater. The tensile stress may accelerate the degradation of the coating. The degree of corrosion damage of the coatings increased with the increase of stress levels. Natural exposure tests of EP and FC coating systems were performed at Sanya test site and Qingdao test site in China, respectively. The correlation between natural exposure test and accelerated exposure test is presented by the acceleration coefficient. A life prediction model of anticorrosive coatings on steel bridge is proposed. The stress coefficient was presented in the life prediction model. The stress coefficient increases with the increase of stress applied on coatings. The proposed life prediction model can provide an important basis for quantitatively describing the failure of anticorrosive coatings and predicting the life of anticorrosive coatings on steel bridges.

Research on Carbonation Life Prediction Model of Recycled Concrete Structures

2013 ◽  
Vol 351-352 ◽  
pp. 1620-1624
Author(s):  
Bing Wang ◽  
Si Yuan Wang ◽  
Shuan Wu ◽  
Xin Wang ◽  
Xia He
Keyword(s):  
Tensile Stress ◽  
Prediction Model ◽  
Empirical Model ◽  
Life Prediction ◽  
Concrete Structures ◽  
Recycled Concrete ◽  
Influence Coefficient ◽  
Carbonation Depth ◽  
Concrete Carbonation ◽  
Life Prediction Model

Based on available achievements on carbonation life prediction model of recycled concrete structures at home and abroad, suggested values of recycled coarse aggregate influence coefficient in the practical mathematics model of recycled concrete carbonation depth was put forward through the comparative analysis. Tensile stress influence coefficient in the empirical model of recycled concrete carbonation depth was revised by mathematical regression analysis. The sensitivity analysis for empirical model was undertaken. Results show that the influencing sequence of the carbonation life impact factors of recycled concrete structures is: cover thickness, recycled concrete strength, relative humidity, environment temperature, tensile stress ratio, CO2 concentration.

scholarly journals Life Prediction Model of Mineral Admixture Cement Based-Materials under Early Age CO2-Erosion

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 413
Author(s):  
Saisai Wang ◽  
Jian Chen ◽  
Xiaodong Wen
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Experimental Tests ◽  
Mineral Admixture ◽  
Model Parameters ◽  
Influence Coefficient ◽  
Test Pieces ◽  
Cement Based Materials ◽  
Particle Group ◽  
Life Prediction Model

Most of the existing models of structural life prediction in early carbonized environment are based on accelerated erosion after standard 28 days of cement-based materials, while cement-based materials in actual engineering are often exposed to air too early. These result in large predictions of the life expectancy of mineral-admixture cement-based materials under early CO2-erosion and affecting the safe use of structures. To this end, different types of mineral doped cement-based material test pieces are formed, and early CO2-erosion experimental tests are carried out. On the basis of the analysis of the existing model, the influence coefficient of CO2-erosion of the mineral admixture Km is introduced, the relevant function is given, and the life prediction model of the mineral admixture cement-based material under the early CO2-erosion is established and the model parameters are determined by using the particle group algorithm (PSO). It has good engineering applicability and guiding significance.

The construction of the life prediction model of 1N and 4N monopropellant thrusters

2013 ◽  
Author(s):  
Go Fujii ◽  
Daisuke Goto ◽  
Hideshi Kagawa ◽  
Shingo Murayama ◽  
Kenichi Kajiwara ◽  
...  
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Life Prediction Model

Wire Fatigue Models for Power Electronic Modules

2003 ◽  
Author(s):  
Karumbu Nathan Meyyappan ◽  
Peter Hansen ◽  
Patrick McCluskey
Keyword(s):  
Prediction Model ◽  
Life Prediction ◽  
Damage Model ◽  
Cyclic Strain ◽  
Temperature Cycling ◽  
Transformation Model ◽  
Time To Failure ◽  
Flexural Failure ◽  
The Wire ◽  
Life Prediction Model

This paper presents two, semi-analytical, physics-of-failure based life prediction model formulations for flexural failure of wires ultrasonically wedge bonded to pads at different heights. The life prediction model consists of a load transformation model and a damage model. The load transformation model determines the cyclic strain is created by a change in wire curvature at the heel of the wire resulting from expansion of the wire and displacement of the frame. The damage model calculates the life based on the strain cycle magnitude and the elastic-plastic fatigue response of the wire. The first formulation provides quick calculation of the time to failure for a wire of known geometry. The second formulation optimizes the wire geometry for maximum time to failure. These model formulations support virtual qualification of power modules where wire flexural fatigue is a dominant failure mechanism. The model has been validated using temperature cycling test results.

Fatigue Life Prediction of Buckling String with Cracks in Horizontal Wells of Mining Engineering

2012 ◽  
Vol 577 ◽  
pp. 127-131 ◽  
Author(s):  
Peng Wang ◽  
Tie Yan ◽  
Xue Liang Bi ◽  
Shi Hui Sun
Keyword(s):  
Fatigue Life ◽  
Prediction Model ◽  
Life Prediction ◽  
Horizontal Well ◽  
Drill Pipe ◽  
Prediction Method ◽  
Drill String ◽  
Fatigue Life Prediction ◽  
Mining Engineering ◽  
Life Prediction Model

Fatigue damage in the rotating drill pipe in the horizontal well of mining engineering is usually resulted from cyclic bending stresses caused by the rotation of the pipe especially when it is passing through curved sections or horizontal sections. This paper studies fatigue life prediction method of rotating drill pipe which is considering initial crack in horizontal well of mining engineering. Forman fatigue life prediction model which considering stress ratio is used to predict drill string fatigue life and the corresponding software has been written. The program can be used to calculate the stress of down hole assembly, can predict stress and alternating load in the process of rotating-on bottom. Therefore, establishing buckling string fatigue life prediction model with cracks can be a good reference to both operation and monitor of the drill pipe for mining engineering.

A LIFE PREDICTION MODEL OF THERMAL BARRIER COATINGS

2010 ◽  
Vol 24 (15n16) ◽  
pp. 3161-3166 ◽  
Author(s):  
LIYONG NI ◽  
CHAO LIU ◽  
CHUNGEN ZHOU
Keyword(s):  
Crack Propagation ◽  
Prediction Model ◽  
Thermal Barrier Coatings ◽  
Life Prediction ◽  
Crack Propagation Rate ◽  
Thermal Barrier ◽  
Critical Crack ◽  
Critical Crack Length ◽  
Barrier Coatings ◽  
Life Prediction Model

The durability and reliability of thermal barrier coatings(TBCs) have become a major concern of hot-section components due to lack of a reliable life prediction model. In this paper, it is found that the failure location of TBCs is at the TBC/TGO interface by a sequence of crack propagation and coalescence process. The critical crack length of failure samples is 8.8mm. The crack propagation rate is 3-10µm/cycle at the beginning and increases largely to 40µm/cycle near coating failure. A life prediction model based a simple fracture mechanics approach is proposed.

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