Structural Reliability Methods Applied in Analysis of Steel Elements Subjected to Fire

2021 ◽  
Vol 147 (12) ◽  
pp. 04021108
Author(s):  
Alverlando Silva Ricardo ◽  
Wellison José de Santana Gomes
Keyword(s):  
Structural Reliability ◽  
Reliability Methods

Simplified Strength Reliability and Integrity Analysis of TTRs

2014 ◽  
Author(s):  
Mir Emad Mousavi ◽  
Sanjeev Upadhye ◽  
Kevin Haverty
Keyword(s):  
Extreme Events ◽  
Structural Reliability ◽  
Probability Distributions ◽  
Probabilistic Approach ◽  
Reliability Assessment ◽  
Cost Effective ◽  
Probability Of Failure ◽  
Annual Probability ◽  
Reliability Methods ◽  
Integrity Analysis

The design of riser systems can be improved if structural reliability methods are used to assess their safety and integrity and confirm that such design meets a target annual probability of failure. TTRs are typically multi–bore assemblies involving several sub-assemblies. The failure of any of the components of a TTR under extreme or service environmental conditions can lead to an immediate failure of the entire assembly and impose a direct risk of damaging the wellheads, conductors, casing and tubing hangers, or other subsea equipment, because they are installed directly on top of the wellhead. However, the actual strength safety of the TTR cannot be examined unless after it is installed and examined under extreme events. Because of the numerous uncertainties associated with the design of TTRs, a probabilistic approach based on structural reliability methods can account for many of those uncertainties and serve as a basis for their reliable and cost-effective design. In turn, a comprehensive reliability assessment of a TTR requires extensive analysis that is considerably more complex and time consuming compared to a conventional deterministic-based analysis. This paper presents a probabilistic-based simplified methodology for the strength reliability assessment of TTR systems. In this method, marginal values on some uncertain model inputs are considered similar to the conventional analysis methods but, some key random variables related to environmental demands and component capacities are considered with their associated probability distributions. As a result, this method can be used to estimate the minimum level of safety of the TTR under extreme events. Additionally, results of the proposed method are discussed for integrity analysis and integrity-based optimal design of the TTR system, which compare the safety of the TTR components and estimate the component Optimality Factors for improving the design integrity and meeting a target minimum annual probability of failure.

scholarly journals Reliability Estimation for Highway Bridges

2020 ◽  
Author(s):  
Nafiseh Kiani
Keyword(s):  
Reliability Index ◽  
Structural Reliability ◽  
Limit State ◽  
Highway Bridges ◽  
Reliability Estimation ◽  
State Function ◽  
Limit States ◽  
Resistance Factors ◽  
Load And Resistance Factors ◽  
Reliability Methods

Structural reliability analysis is necessary to predict the uncertainties which may endanger the safety of structures during their lifetime. Structural uncertainties are associated with design, construction and operation stages. In design of structures, different limit states or failure functions are suggested to be considered by design specifications. Load and resistance factors are two essential parameters which have significant impact on evaluating the uncertainties. These load and resistance factors are commonly determined using structural reliability methods. The purpose of this study is to determine the reliability index for a typical highway bridge by considering the maximum moment generated by vehicle live loads on the bridge as a random variable. The limit state function was formulated and reliability index was determined using the First Order Reliability Methods (FORM) method.

Pipeline Integrity Reliability Analysis Levels

2016 ◽  
Author(s):  
Sherif Hassanien ◽  
Len Leblanc ◽  
Javier Cuervo ◽  
Karmun Cheng
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Failure Modes ◽  
Oil And Gas ◽  
Prediction Models ◽  
Metal Loss ◽  
Operating Pressure ◽  
Reliability Engineering ◽  
Reliability Methods ◽  
Types Of Information

Reliability engineering science is a mature discipline that has been used extensively in industries such as aviation, nuclear energy, automobiles, and structures. The application of reliability principles (especially structural reliability) in oil and gas transmission pipelines is still an active area of development. The advent of high resolution in-line inspections tools (ILI) facilitates a formal application/utilization of reliability methods in pipeline integrity in order to safely manage deformation, metal loss, and crack threats. At the same time, the massive amount of ILI data, their associated uncertainties, and the availability/accuracy of failure prediction models present a challenge for operators to effectively implement the use of reliability analysis to check the safety of integrity programs within available timeframes. On the other hand, approximate reliability techniques may affect the analysis in terms of both accuracy and precision. In this paper, a Pipeline Integrity Reliability Analysis (PIRA) approach is presented where the sophistication of the reliability analysis is staged into three levels: PIRA levels I, II and III. The three PIRA levels correspond to different representations of integrity uncertainties, uses of available validated/calibrated data, uses of statistical models for operating pressure and resistance random variables, implementation of reliability methods, and consideration of failure modes. Moreover, PIRA levels allow for improved integration of reliability analysis with the existing timelines/stages of traditional integrity programs, such that integrity data are updated as the integrity program progresses. The proposed integrity reliability approach allows for the delivery of safety checks leveraging all types of information available at any given point in time. In addition, the approach provides a full understanding of the strengths and weaknesses of each PIRA level. Pipeline corrosion case studies are provided herein to illustrate how the PIRA Levels can be applied to integrity programs.

scholarly journals Structural Reliability Methods Applied to Power Switch Devices: Example of an Aeronautical IGBT Module

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Adrien Zéanh ◽  
Olivier Dalverny ◽  
Arezki Bouzourene ◽  
Christophe Bruzy
Keyword(s):  
Structural Reliability ◽  
Low Cycle Fatigue ◽  
Numerical Procedure ◽  
Thermomechanical Response ◽  
Test Configuration ◽  
Insulated Gate Bipolar Transistor ◽  
Igbt Module ◽  
Reliability Method ◽  
Fatigue Model ◽  
Reliability Methods

In this paper, an Insulated Gate Bipolar Transistor (IGBT) module designed for aeronautic applications is investigated using structural reliability methods coupled with Finite Elements (FE) modeling. The lifetime of the module with respect to its solder joints failure, is evaluated using its thermomechanical response, in association with a low cycle fatigue model. The simulation of an aeronautic typical Accelerated Thermal Cycling (ATC) test configuration allows checking in a first step, the relevancy of the numerical procedure by assessing the experimental lifetime of the connections, and comparing them to experimental results. Then, the structural reliability of the module is evaluated over the target aircraft predicted useful lifetime, comparing the First Order Reliability Method (FORM) and Monte-Carlo Simulation (M-CS). The appropriate temperature mission profile and flight time are therefore considered with their scatters, in addition to those of the parameters of the fatigue model. Regarding these latter parameters, a simulation based approach is proposed and applied for the determination of their probability density function (pdf). For reasonable reliability analysis time, the thermomechanical response of the module was surrogated using Kriging metamodels. The paper ends with the exploitation of the reliability importance factors for identifying and proposing improvements, with the demonstration of considerable reliability increase.

Analysis of Structural Reliability Based on Stochastic Response Surface Method

2012 ◽  
Vol 182-183 ◽  
pp. 1533-1536
Author(s):  
Liu Ying
Keyword(s):  
Response Surface ◽  
Response Surface Method ◽  
Structural Reliability ◽  
Structural Type ◽  
Stochastic Response ◽  
Stochastic Response Surface Method ◽  
Surface Method ◽  
Analysis Technique ◽  
Polynomial Series ◽  
Reliability Methods

A system reliability analysis technique has been proposed in the paper, based on stochastic response surface method. Each input is translated into standard random variables, and the output is expanded into Hermite polynomial series. The coefficients of the expansion of the response are obtained by a regression method. The amount of calculation can be greatly reduced, compared to conventional reliability methods such as Monte-Carlo simulation. The proposed technique can be applied to any structural type.

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