Optimal Reliability and Cost of Non-Repairable Systems Subject to Two Failure Modes Considering Correlated Failures

2018 ◽  
Vol 25 (05) ◽  
pp. 1850024
Author(s):  
Anusha Krishna Murthy ◽  
Saikath Bhattacharya ◽  
Lance Fiondella
Keyword(s):  
Failure Mode ◽  
System Reliability ◽  
Failure Modes ◽  
Optimal Number ◽  
Optimal Designs ◽  
Repairable Systems ◽  
Independent Manner ◽  
Reliability Models ◽  
Correlated Failures ◽  
The Impact

Most reliability models assume that components and systems experience one failure mode. Several systems such as hardware, however, are prone to more than one mode of failure. Past two-failure mode research derives equations to maximize reliability or minimize cost by identifying the optimal number of components. However, many if not all of these equations are derived from models that make the simplifying assumption that components fail in a statistically independent manner. In this paper, models to assess the impact of correlation on two-failure mode system reliability and cost are developed and corresponding expressions for reliability and cost optimal designs derived. Our illustrations demonstrate that, despite correlation, the approach identifies reliability and cost optimal designs.

Significant Failure Mode Identification for a CFST Arch Bridge System

2013 ◽  
Vol 540 ◽  
pp. 11-19
Author(s):  
Xin Gao ◽  
Lei Wang ◽  
Tong Zhang
Keyword(s):  
Failure Mode ◽  
System Reliability ◽  
Structural Reliability ◽  
Failure Modes ◽  
Reliability Estimation ◽  
Mode Identification ◽  
Bridge Safety ◽  
Finite Element Package ◽  
Arch Bridges ◽  
Failure Mode Identification

The structural reliability analysis is the widely accepted method for bridge safety assessment. Identification the subset of significant failure modes is the most important part of system reliability estimation. In this paper, a stage critical strength branch and bound algorithm is proposed for the failure mode identification of bridge systems. The innovative method is implemented in the combination with the finite element package ANSYS and the MATLAB procedure. The suggest method is applied to a concrete filled steel tubular (CFST) arch bridges. The results reveal various combinations of the failure modes in significantly reduced time and efforts in comparison to the previous permutation method. Additionally, the suggested method can be used for the verification of the system reliability with more specific predictions of the failure mode.

Passive System Reliability Modeling of the Combination of Failure Modes

2016 ◽  
Author(s):  
Luciano Burgazzi
Keyword(s):  
Reliability Analysis ◽  
Failure Mode ◽  
System Reliability ◽  
Probabilistic Models ◽  
Failure Modes ◽  
Natural Circulation ◽  
Heat Transfer Process ◽  
Passive System ◽  
Modes Of Failure ◽  
Degradation Failure

Innovative probabilistic models to extend the reliability analysis of passive systems under different modes of failure are proposed. The prevailing failure mode on the system can be predicted through the failure probability assessment on each specific mode. A realistic case is presented to analyze a passive system with two kinds of major failure modes — natural circulation stoppage due to e.g., isolation valve closure (a catastrophic failure) and heat transfer process degradation due to e.g., deposit thickness on component surfaces (a degradation failure). Modeling of each individual failure mode together with system reliability analysis is presented and results are discussed.

Approach for the Evaluation of the Impact of Potential Software Failures in Software-Based Instrumentation and Control (I&C) Equipment in Nuclear Power Plants

2016 ◽  
Author(s):  
Hervé Mbonjo ◽  
Manuela Jopen ◽  
Birte Ulrich ◽  
Dagmar Sommer
Keyword(s):  
Failure Mode ◽  
Nuclear Power ◽  
Power Plants ◽  
Failure Modes ◽  
Operating Experience ◽  
Generic Model ◽  
Software Failures ◽  
Software Failure ◽  
Potential Safety ◽  
The Impact

In this paper we present an approach for the evaluation and assessment of the impact of software failures in software-based I&C systems of NPPs. The proposed two-step approach includes at the first step the identification of software failure modes on the basis of review of operating experience gained with software-based I&C systems and equipment. All probable software failures in software-based I&C systems should be identified and classified according to e. g. the concerned system, the observed software failure mode and to their actual and potential safety relevance. In a second step an evaluation of the potential impact of identified safety relevant software failure modes in a software-based I&C system shall be performed. The evaluation shall be done by means of a failure mode and effects analysis (FMEA) using a generic model of the software-based I&C system, i.e. software failure modes are postulated in the I&C system and their potential safety-relevant impact is analyzed.

Failure Mechanisms of Weld Bonded Lap Joints Between Composite/Metal Adherends

2014 ◽  
Author(s):  
Lijun Li ◽  
Lingyu Sun
Keyword(s):  
Failure Mode ◽  
Adhesive Bonding ◽  
Failure Modes ◽  
Load Transfer ◽  
Engineering Application ◽  
Element Model ◽  
Simulation Method ◽  
Lap Joints ◽  
Transfer Path ◽  
The Impact

Weld-bonding, a combination of spot welding and adhesive bonding, is a primary method of joining the composite underbody to the steel body-in-white (BIW). This concept is provided by the Automotive Composites Consortium (ACC) to ensure the compatibility with the OEM assembly processes. This paper established the finite element model of the weld bonded lap joint based on the published specimen dimensions, and compared the ultimate load and failure mode with their experimental results. Their good agreements demonstrated the accuracy of the numerical model and simulation method. Using this model, the progressive failures within the joints were predicted under static tensile loading and impact loading, respectively. The impact resistant capability of this joint was evaluated and the load transfer path among the adhesives, welded spot, composite and HSS adherend was discussed. The influences of relative thickness and relative stiffness between the adhesives and the two adherends on the failure modes were studied numerically, and the map chart for failure mode prediction was provided for weld bonded lap joints of bi-materials adherends, which is helpful for engineering application.

Research on Failure Criterion of Lattice Jib Structural System Reliability

2014 ◽  
Vol 551 ◽  
pp. 194-201
Author(s):  
Ge Ning Xu ◽  
Shuai Lei He ◽  
Rui Gang Yang
Keyword(s):  
Failure Mode ◽  
Failure Criterion ◽  
System Reliability ◽  
Mechanical Characteristics ◽  
Failure Modes ◽  
Structural System ◽  
Structure System ◽  
Structural System Reliability ◽  
Overall Stability ◽  
Jib Structure

In Four-column limb lattice jib structure system as the research object, considering the structure and mechanical characteristics, combining with the allowable stress method, from the failure mode of static strength, stiffness, overall stability and local stability to build lattice jib structure system reliability failure criterion. Based on the influence of parameter perturbation calculation of four-column limb lattice jib structure system, get the length of the jib, lifting weight, jib elevation, hoisting load bearing point offset, the proportion of wind environment on the influence of different failure modes and failure change law, as the main failure mode of the decision to provide the basis and methods.

scholarly journals Reliability of Supply and the Impact of Weather Exposure and Protection System Failures

2020 ◽  
Vol 11 (1) ◽  
pp. 182
Author(s):  
Erlend Sandø Kiel ◽  
Gerd Hovin Kjølle
Keyword(s):  
System Reliability ◽  
Failure Modes ◽  
Extreme Weather ◽  
Test System ◽  
Protection System ◽  
Electrical Transmission ◽  
System Failures ◽  
Reliability Indices ◽  
The Impact

Extreme weather is known to cause failure bunching in electrical transmission systems. However, protection systems can also contribute to the worsening of the system state through various failure modes—spontaneous, missing or unwanted operation. The latter two types of failures only occur when an initial failure has happened, and thus are more likely to happen when the probability of failure of transmission lines is high, such as in an extreme weather scenario. This causes an exacerbation of failure bunching effects, increasing the risk of blackouts, or High Impact Low Probability (HILP) events. This paper describes a method to model transmission line failure rates, considering both protection system reliability and extreme weather exposure. A case study is presented using the IEEE 24 bus Reliability Test System (RTS) test system. The case study, using both an approximate method as well as a time-series approach to calculate reliability indices, demonstrates both a compact generalization of including protection system failures in reliability analysis, as well as the interaction between weather exposure and protection system failures and its impact on power system reliability indices. The results show that the inclusion of protection system failures can have a large impact on the estimated occurrence of higher order contingencies for adjacent lines, especially for lines with correlated weather exposure.

scholarly journals A Novel Approach to Support Failure Mode, Effects, and Criticality Analysis Based on Complex Networks

Entropy ◽  
2019 ◽  
Vol 21 (12) ◽  
pp. 1230 ◽  
Author(s):  
Lixiang Wang ◽  
Wei Dai ◽  
Guixiu Luo ◽  
Yu Zhao
Keyword(s):  
Complex Networks ◽  
Failure Mode ◽  
Failure Modes ◽  
Weighted Graph ◽  
Complex Network Theory ◽  
Mode Effects ◽  
Novel Approach ◽  
Potential Failure ◽  
The Impact ◽  
Criticality Analysis

Failure Mode, Effects and Criticality Analysis (FMECA) is a method which involves quantitative failure analysis. It systematically examines potential failure modes in a system, as well as the components of the system, to determine the impact of a failure. In addition, it is one of the most powerful techniques used for risk assessment and maintenance management. However, various drawbacks are inherent to the classical FMECA method, especially in ranking failure modes. This paper proposes a novel approach that uses complex networks theory to support FMECA. Firstly, the failure modes and their causes and effects are defined as nodes, and according to the logical relationship between failure modes, and their causes and effects, a weighted graph is established. Secondly, we use complex network theory to analyze the weighted graph, and the entropy centrality approach is applied to identify influential nodes. Finally, a real-world case is presented to illustrate and verify the proposed method.

Reliability Analysis on Competitive Failure Processes under Multiple Failure Modes

2013 ◽  
Vol 442 ◽  
pp. 257-263
Author(s):  
Hui Bing Hao ◽  
Chun Su
Keyword(s):  
Sensitivity Analysis ◽  
Reliability Analysis ◽  
System Reliability ◽  
Failure Modes ◽  
New Model ◽  
Degradation Processes ◽  
Independent Case ◽  
Failure Models ◽  
Random Shocks ◽  
The Impact

In this article, a new multiple competing failure models proposed, in which multiple degradation processes and random shocks are considered. The shocks have a significant impact on system reliability, and the system reliability under not considering the impact of shocks is much higher than the impact of shocks is considered. In addition, the influences of the correlation among different degradation processes are also considered in this article. We can find that the reliability with considering the dependent case is higher than the independent case reliability. Thus the dependence of the two degradation processes is non-negligible. A numerical example with reliability analysis and sensitivity analysis is discussed to illustrate the proposed the new model.

A Simulation and Modeling Based Reliability Requirements Assessment Methodology

2014 ◽  
Author(s):  
Tomonori Honda ◽  
Eric Saund ◽  
Ion Matei ◽  
Bill Janssen ◽  
Bhaskar Saha ◽  
...  
Keyword(s):  
System Reliability ◽  
Failure Modes ◽  
Vehicle Design ◽  
Assessment Methodology ◽  
Exploration Tool ◽  
Design Case Study ◽  
The Cost ◽  
Design Cost ◽  
The Impact

To minimize the design cost of a complex system and maximize performance, a design team ideally must be able to quantify reliability and mitigate risk at the earliest phases of the design process, where 80% of the cost is committed. This paper demonstrates the capabilities of a new System Reliability Exploration Tool based on the improved simulation capabilities of a system called Fault-Augmented Modelica Extension (FAME). This novel tool combines concepts from FMEA, traditional Reliability Analysis, and Quality Engineering to identify, gain insight, and quantify the impact of component failure modes through time evolution of a system’s lifecycle. We illustrate how to use the FAME System Reliability Exploration Tool through a vehicle design case study.

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