scholarly journals Application of Bayesian Method to Determining Reliability Index on Composite Material Strength

2016 ◽  
Vol 42 (6) ◽  
pp. 235-240
Author(s):  
Seiichi ITO ◽  
Sunao SUGIMOTO ◽  
Tetsuya MORIMOTO ◽  
Hisaya KATOH
Keyword(s):  
Composite Material ◽  
Reliability Index ◽  
Bayesian Method ◽  
Material Strength

Study on System Reliability Updating through Inspection Information for Existing Cable-Stayed Bridges

2011 ◽  
Vol 250-253 ◽  
pp. 2011-2015 ◽  
Author(s):  
Jin Song Zhu ◽  
Jian Hui Wu
Keyword(s):  
Service Life ◽  
Failure Probability ◽  
System Reliability ◽  
Reliability Index ◽  
Bayesian Method ◽  
Residual Life ◽  
Random Variables ◽  
Modified Model ◽  
Cable Stayed Bridge ◽  
Cable Stayed Bridges

In order to accurately evaluate the reliability of the existing cable-stayed bridge, a method based on inspection information is proposed to update the system reliability. Using Bayesian method and inspection information, the modified model of cable-stayed bridge random variables is established, and then the failure probability of cable-stayed bridge components is updated. Theβ-Tcurves of changing rules of inspection information on system reliability index and service life are obtained. The method has been applied to a cable-stayed bridge, the results show that the proposed method is effective to update the system reliability and can predict the residual life of the existing cable-stayed bridges.

Reliability analysis of foundation stability for gravity platforms in the North Sea

1989 ◽  
Vol 26 (3) ◽  
pp. 359-368 ◽  
Author(s):  
Tien H. Wu ◽  
Oddvar Kjekstad ◽  
In-Mo Lee ◽  
Suzanne Lacasse
Keyword(s):  
North Sea ◽  
Reliability Index ◽  
Site Investigation ◽  
Offshore Structures ◽  
Material Strength ◽  
Strength Measurement ◽  
The North ◽  
The North Sea ◽  
Coefficients Of Variations ◽  
The Mean

The uncertainties encountered in the evaluation of foundation stability for four offshore gravity structures in the North Sea are reviewed. The uncertainties include those about the load, the material type, the material strength, and the analytical method. The means and coefficients of variations of these are used as inputs to compute the mean and coefficient of variation of the safety factor and the reliability index. The latter are used to assess the effect of various options in site exploration and strength measurement on foundation reliability. Key words: foundation, gravity platforms, offshore structures, probability, reliability, shear strength, site investigation, stability.

Study on Mechanical Properties of Wood Plastic Composites

2012 ◽  
Vol 182-183 ◽  
pp. 307-310
Author(s):  
Fang Huang
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Matrix Material ◽  
Material Strength ◽  
Dispersed Phase ◽  
Wood Plastic Composites ◽  
Reinforced Composite ◽  
Plastic Composites ◽  
Pure Matrix

Composite material has many excellent properties, current, receives special attention was paid to its mechanical properties. By adding the dispersed phase can make the strength of the composites than did not join the dispersed phase of pure matrix material strength several times or several times. Composite materials are often called fiber ( or other dispersed phase) reinforced composite materials.

Effect of Glass Fiber Geometry on Composite Material Strength

ARS Journal ◽  
1961 ◽  
Vol 31 (9) ◽  
pp. 1260-1265 ◽  
Author(s):  
JAMES E. BELL
Keyword(s):  
Composite Material ◽  
Glass Fiber ◽  
Material Strength

scholarly journals Thermal and Acoustic Insulating Gypsum Composite Material with Improved Water Resistance

2020 ◽  
Vol 14 (2) ◽  
pp. 89-93
Author(s):  
Volodimir Kersh ◽  
Andriy Kolesnikov ◽  
Mikola Hlitsov ◽  
Sergіi Gedulyan
Keyword(s):  
Composite Material ◽  
Thermal Insulation ◽  
High Resistance ◽  
Water Resistance ◽  
Resistance Index ◽  
Sound Insulation ◽  
Material Strength ◽  
Building Heat ◽  
Softening Coefficient

The article discusses methods for obtaining building heat and sound insulating composite material based on gypsum with high resistance to water. An additional characteristic is considered - the water resistance index, in which the role of material strength in the wet state is enhanced. The proposed characteristic is used to optimize the heat and sound insulating composition based on gypsum. The material contains matrix gypsum-cement-ash binder and a mixture of aggregates. The result of the planned experiment shows that the water resistance index more adequately reflects the strength of the composite in the wet state compared to the softening coefficient. An optimization of the complex properties of the composite is given in accordance with its intended purpose. As a result of the study, an optimal waterproof composition with improved thermal insulation and sound insulation characteristics was obtained.

Permit Vehicle Routing Using Reliability-Based Evaluation Procedures

2000 ◽  
Vol 1696 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Joan R. Casas
Keyword(s):  
Vehicle Routing ◽  
Reliability Index ◽  
Traffic Load ◽  
Evaluation Procedure ◽  
Material Strength ◽  
Limit States ◽  
Critical Limit ◽  
Highway Network ◽  
Definition Of ◽  
Existing Bridges

The works carried out within the framework of the development of an automatic system for permit vehicle routing on the Spanish National Highway network are described. The focus is on the methodology adopted for analysis of the old existing bridges. Because information about bridge properties (geometry, material strength) and design live load is unknown, the evaluation procedure combines the information provided by in situ measurements and inspection with a reliability-based evaluation. The reliability index for the most critical limit states derived from the maximum effects due to actual traffic on the bridge is adopted as the comparison value to define a passage criterion. Any permit crossing the bridge alone or with traffic restrictions leading to a lower reliability index will not be allowed on the bridge. The actual traffic load is obtained from existing traffic records using a model of traffic flow. The method is applied to 10 bridges fully representative of the old and nondocumented bridges most often encountered on Spanish highways. The final result is definition of the standard permits as presented in Eurocode 1 that are allowed on the bridge. From the most unfavorable permit, a criterion is derived concerning the actual vehicle permits.

Development of Reliability Assessment Method for Piping Containing Local Metal Loss at Structure Discontinuity

2016 ◽  
Author(s):  
Qiang Qu ◽  
Satoshi Izumi ◽  
Shinsuke Sakai
Keyword(s):  
Sensitivity Analysis ◽  
Tensile Strength ◽  
Internal Pressure ◽  
Reliability Index ◽  
Reliability Assessment ◽  
Safety Margin ◽  
Material Strength ◽  
Metal Loss ◽  
Deterministic Analysis ◽  
Surface Method

In chemical plants, Corrosion Under Insulation (CUI) is a typical maintenance issue of internal pressed pipes. This form of localized corrosion leads to metal loss at the outside surface of pipes, reduces the pipe’s resistance to internal pressure [1]. Once the local metal loss is inspected, it is important to apply a Fitness-For-Service (FFS) assessment to evaluate the remaining safety margin against working internal pressure. However, if the local metal loss occurs at the piping discontinuity, it is impossible to calculate the critical collapsing pressure without any existing theoretical expression. Moreover, evaluation based upon standards may produce too much conservative evaluation and lead to unnecessary repairing-replacement cost. In this study, both deterministic analysis and probabilistic reliability analysis are performed to evaluate the safety margin of piping containing local metal loss at piping branch connection, and the obtained results are compared with those evaluated based upon API579-1/ASME FFS-1 standard. In addition, sensitivity analysis is conducted to show the dependence of metal loss geometries regarding both width and depth, material strength and working internal pressure on the safety margin. Finally, a proper reliability assessment procedure by using advanced Response Surface Method (RSM) is proposed. In the deterministic analysis part, a FEM structural analysis is performed to calculate the critical collapsing internal pressures (CIP) for several cases of various metal loss geometries regarding width and depth and material tensile strength. These results are compared with maximum allowable working internal pressure (MAWP) calculated by the procedures which are provided in API579-1/ASME FFS-1 standard. (The safety margin is defined as CIP/ MAWP). It is shown that the safety margins are greater than 6 in most of the cases. Since there are uncertainties in the geometrical dimensions of local metal loss, material tensile strength and working internal pressure, it is necessary to perform a reliability analysis to quantify the probability of failure (Pf) caused by these uncertainties. In the probabilistic analysis part, the metal loss geometries, material strength and internal pressure are considered as random variable with distributions. The reliability index of each group of geometries-strength-pressure combinations is calculated by first order reliability method (FORM). The reliability index of the case working under MAWP is also investigated. In order to define the limit state function, response surface method is used to predict the response which relates the critical collapsing internal pressure to the metal loss geometries and material strength. Finally, the sensitivity analysis is performed to clarify the dependence of metal loss geometries, material strength, and internal pressure on the Pf, and to specify the dominant variables and negligible variables.

Effect of China Clay on Mechanical Properties of AA7075/B4C Hybrid Composite Fabricated by Powder Metallurgy Techniques

2020 ◽  
Author(s):  
Krishna Murari Pandey ◽  
Guttikonda Manohar ◽  
Saikat Ranjan Maity
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Volume Fraction ◽  
High Strength ◽  
Industrial Applications ◽  
Material Strength ◽  
Matrix Composites ◽  
China Clay ◽  
Hardness Tests ◽  
Compaction Processes

Abstract Composite materials are very predominant in the areas of industrial applications, aerospace and defense sectors. Aluminium metal matrix composites are main targeted materials by many researchers because of its low density, high strength, corrosion resistance and economical that makes material suitable for aerospace and automobile sectors. In this work effect of china clay volume fraction on mechanical properties of AA7075/B4C composite was investigated. Effect of china clay volume fraction on mechanical properties was analyzed with the help of results obtained by XRD, tensile, compression and micro hardness tests. From the experimentation analysis and results it was clear that added china clay acts as effective binder material for efficient compaction and ejection of green compacts from the die material after cold compaction processes and gives high strength to the composite material up to 7% volume fraction in sintered composite while in tensile strength after that material strength starts to degrade. In this work critical volume fractions of china clay in AA7075/B4C composite was investigated in tensile, compression and hardness. Further, effect of heat treatment on mechanical properties of the composite material was investigated.

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