Structural Reliability Applications in Developing Risk-Based Inspection Plans for a Floating Production Installation

2004 ◽  
Author(s):  
A. Ku ◽  
C. Serratella ◽  
R. Spong ◽  
R. Basu ◽  
G. Wang ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Structural Reliability ◽  
Fatigue Behavior ◽  
Statistical Correlation ◽  
Structural Components ◽  
Fatigue Reliability ◽  
Load Combination ◽  
Straightforward Method ◽  
Combination Approach

This paper outlines the essential steps taken in performing structural reliability calculations during the process of laying out a risk-based inspection program. The structural reliability analysis described in this paper essentially takes the deterministic finite element method (FEM) stress/fatigue analysis results, coupled with uncertain degradation mechanisms (e.g. corrosion rate, crack propagating parameters, etc.), and tracks the time-varying structural reliability index of the structural components under consideration. This can then be used to determine the timing for inspection of structural components. For the assessment of structural strength, an efficient and straightforward method is proposed to calculate the time-variant reliability index. This method is verified by an example problem and compared to the random process first-passage reliability solutions. Load combination issue is briefly discussed, in which an approach stems from the ABS Dynamic Loading Approach (DLA) coupled with concepts from Turkstra’s rule. This proposed simplistic load combination approach is verified through an example problem in which the result is compared to the solution calculated from a more sophisticated approach. Establishment of target reliability levels is also briefly discussed. For the assessment of fatigue behavior for welded connections, both S-N curve based and fracture mechanics based reliability methods are discussed. Their usefulness will be discussed in terms of both inspection interval as well as selecting the proper sampling percentage of connections to inspect. Statistical correlation among a group of similar connections is discussed to assist the selection of appropriate locations in the population of the aforementioned sampling. The usefulness of fatigue reliability analysis is also demonstrated by an example problem.

Estimation of Structural Reliability Under Random Fatigue Conditions

1991 ◽  
Author(s):  
J. D. Baldwin ◽  
J. G. Thacker ◽  
T. T. Baber
Keyword(s):  
Standard Deviation ◽  
Structural Reliability ◽  
Endurance Limit ◽  
Narrow Band ◽  
Fatigue Behavior ◽  
Fatigue Reliability ◽  
Structural Element ◽  
Gaussian Random Process ◽  
The Mean ◽  
Random Fatigue

Abstract A procedure for determining the reliability of a structural element or machine part is presented. The solution assumes that the stress history in the part can be described by a narrow band, stationary, Gaussian random process and that the fatigue behavior of the part is governed by the classical S-N curve. Endurance limit modifications are discussed and a procedure is presented for determining the mean and standard deviation of the static stresses acting throughout a structure. A numerical example is presented showing the method applied to estimate the fatigue reliability of a power wheelchair frame.

scholarly journals The structural reliability analysis using explicit neural state functions

2019 ◽  
Vol 262 ◽  
pp. 10002 ◽  
Author(s):  
Agnieszka Dudzik ◽  
Beata Potrzeszcz-Sut
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Structural Reliability ◽  
Limit State ◽  
Random Variables ◽  
Transformation Method ◽  
Stability Loss ◽  
Cross Sectional ◽  
Component Reliability ◽  
State Functions

The present study considers the problems of stability and reliability of spatial truss susceptible to stability loss from the condition of node snapping. In the reliability analysis of structure, uncertain parameters, such us load magnitudes, cross-sectional area, modulus of elasticity are represented by random variables. Random variables are not correlated. The criterion of structural failure is expressed by the condition of non-exceeding the admissible load multiplier. In the performed analyses explicit form of the random variables function were used. To formulate explicit limit state functions the neural networks is used. In the paper only the time independent component reliability analysis problems are considered. The NUMPRESS software, created at the IFTR PAS, was used in the reliability analysis. The Hasofer-Lind index in conjunction with transformation method in the FORM was used as a reliability measure. The primary research method is the FORM method. In order to verify the correctness of the calculation SORM and Monte Carlo methods are used. The values of reliability index for different descriptions of mathematical model of the structure were determined. The sensitivity of reliability index to the random variables is defined.

Fatigue Reliability Analysis and Design for Structural Components in Quasi‐One‐Shot Device

PAMM ◽  
2018 ◽  
Vol 18 (1) ◽  
Author(s):  
Haiqiao Wang ◽  
Min Chen ◽  
Xiaofei Yao ◽  
Zhiyuan Liu ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Structural Components ◽  
Fatigue Reliability ◽  
Analysis And Design

scholarly journals Time-Dependent Reliability Analysis of Plate-Stiffened Prismatic Pressure Vessel with Corrosion

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1544
Author(s):  
Younseok Choi ◽  
Junkeon Ahn ◽  
Daejun Chang
Keyword(s):  
Reliability Analysis ◽  
Pitting Corrosion ◽  
Pressure Vessel ◽  
Reliability Index ◽  
Structural Reliability ◽  
Pressure Vessels ◽  
Outer Shell ◽  
Time Dependent ◽  
General Corrosion ◽  
Reliability Method

In this study, the structural reliability of plate-stiffened prismatic pressure vessels was analyzed over time. A reliability analysis was performed using a time-dependent structural reliability method based on the response surface method (RSM). The plate-stiffened prismatic pressure vessel had a rectangular cross-section with repeated internal load-bearing structures. For the structural analysis, this repeated structure was modeled as a strip, and a structural reliability analysis was performed to identify changes in the reliability index when general corrosion and pitting corrosion occurred in the outer shell. Pitting corrosion was assumed to be randomly distributed on the outer shell, and the reliability index according to the degree of pit (DOP) and time was analyzed. Analysis results confirmed that the change in the reliability index was larger when pitting corrosion was applied compared with when only general corrosion was applied. Additionally, it was confirmed that above a certain DOP, the reliability index was affected.

scholarly journals Structural Reliability Analysis of Laminated CMC Components

1991 ◽  
Author(s):  
Stephen F. Duffy ◽  
Joseph L. Palko ◽  
John P. Gyekenyesi
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix ◽  
Estimation Procedure ◽  
Matrix Cracking ◽  
Full Potential ◽  
Structural Components ◽  
Aerospace Applications ◽  
Parameter Estimation Procedure

For laminated ceramic matrix composite (CMC) materials to realize their full potential in aerospace applications design, methods and protocols are a necessity. This paper focuses on the time-independent failure response of these materials and presents a reliability analysis associated with the initiation of matrix cracking. It highlights a public domain computer algorithm that has been coupled with the laminate analysis of a finite element code and which serves as a design aid to analyze structural components made from laminated CMC materials. Issues relevant to the effect of the size of the component are discussed, and a parameter estimation procedure is presented. The estimation procedure allows three parameters to be calculated from a failure population that has an underlying Weibull distribution.

Structural Reliability Analysis with Uncertainty-but-Bounded Parameters Based on Meshless Method

2010 ◽  
Vol 163-167 ◽  
pp. 3034-3041
Author(s):  
Wei Zhao ◽  
J.K. Liu ◽  
Qiu Wei Yang
Keyword(s):  
Reliability Analysis ◽  
Meshless Method ◽  
Reliability Index ◽  
Structural Reliability ◽  
Strain Analysis ◽  
Optimization Theory ◽  
Upper And Lower Bounds ◽  
Probability Method ◽  
Structural Reliability Analysis ◽  
Interval Reliability

The structural reliability analysis with uncertainty-but-bounded parameters is considered in this paper. Each uncertain-but-bounded parameter is represented as an interval number or vector, an interval reliability index is defined and discussed. Due to the wide application of the Meshless method, it is used in structural stress and strain analysis. The target variable of requiring reliability analysis is estimated via Taylor expansion. Based on optimization theory and vertex solution theorem, the upper and lower bounds of the target variables are obtained, and also the interval reliability index. A typical elastostatics example is presented to illustrate the computational aspects of interval reliability analysis in comparison with the traditional probability method, it can be seen that the result calculated by the vertex solution theorem is consistent with that calculated by probability method.

Progresses on the Fatigue Reliability Research of China Railway Vehicles in Recent Decade

2008 ◽  
Vol 44-46 ◽  
pp. 1-14 ◽  
Author(s):  
Zhi Yun Shen ◽  
Yong Xiang Zhao ◽  
Bing Yang ◽  
Wei Hua Zhang
Keyword(s):  
Reliability Analysis ◽  
Fatigue Behavior ◽  
Fatigue Cracking ◽  
Recent Decade ◽  
State Theory ◽  
Contact Forces ◽  
Dynamics Simulation ◽  
Fatigue Reliability ◽  
Railway Vehicles ◽  
China Railway

Main progresses are reviewed and prospected from four elements on the fatigue reliability analysis research of China railway vehicles during recent decade. First, material fatigue database has been moderately developed and an emphasis was placed on the systemized fatigue properties. Second, a great of on-line inspections have been performed on the wheel-track contact forces and service stresses of key structures. A reliable vehicle dynamics simulation technique has been developed for simulating the contact forces and a multi-variable quadratic regression approach has been proposed to calculate the service stresses for recuing imperfect inspections. Third, systemized fatigue reliability researches have been made on improved fatigue limit measurement, probabilistic S-N curves, scale-deduced fatigue behavior, design Goodman-Smith diagram, and reliability analysis approach to address on the real super-long life of railway vehicle’s structures. Fourth, a critical safety state theory is established to address the time-dependent off-round wheel wear and the interactive fatigue damage between components. Fatigue cracking threshold measurement is improved. And a fatigue crack growth modeling is developed to cover entire physical process from the threshold to the fracture. The axle critical safety sizes are determined under considering the off-round wheel and the wheel critical safety wear sizes are measured to ensure the axle expected safety life. All researches are valuable to be further studied.

scholarly journals Comparative Study of Structural Reliability Assessment Methods for Offshore Wind Turbine Jacket Support Structures

2020 ◽  
Vol 10 (3) ◽  
pp. 860 ◽  
Author(s):  
Abdulhakim Adeoye Shittu ◽  
Ali Mehmanparast ◽  
Lin Wang ◽  
Konstantinos Salonitis ◽  
Athanasios Kolios
Keyword(s):  
Reliability Index ◽  
Structural Reliability ◽  
Reliability Assessment ◽  
Probability Of Failure ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Support Structures ◽  
Structural Components ◽  
Support Structure ◽  
Design Constraints

Offshore wind turbines (OWTs) are deployed in harsh environments often characterized by highly stochastic loads and resistance properties, thus necessitating the need for structural reliability assessment (SRA) to account for such uncertainties systematically. In this work, the SRA of an OWT jacket-type support structure is conducted, applying two stochastic methods to predict the safety level of the structure considering various design constraints. The first method refers to a commercial finite element analysis (FEA) package (DesignXplorer© from ANSYS) which employs direct simulations and the six sigma analysis function applying Latin hypercube sampling (LHS) to predict the probability of failure. The second method develops a non-intrusive formulation which maps the response of the structure through a finite number of simulations to develop a response surface, and then employs first-order reliability methods (FORM) to evaluate the reliability index and, subsequently, the probability of failure. In this analysis, five design constraints were considered: stress, fatigue, deformation, buckling, and vibration. The two methods were applied to a baseline 10-MW OWT jacket-type support structure to identify critical components. The results revealed that, for the inherent stochastic conditions, the structural components can safely withstand such conditions, as the reliability index values were found acceptable when compared with allowable values from design standards. The reliability assessment results revealed that the fatigue performance is the design-driving criterion for structural components of OWT support structures. While there was good agreement in the safety index values predicted by both methods, a limitation of the direct simulation method is in its requirement for a prohibitively large number of simulations to estimate the very low probabilities of failure in the deformation and buckling constraint cases. This limitation can be overcome through the non-intrusive formulation presented in this work.

A new method for structural non-probabilistic reliability analysis based on interval analysis

2016 ◽  
Vol 12 (1) ◽  
pp. 73-79
Author(s):  
Xing-wang Gou ◽  
Ai-jun Li ◽  
La-quan Luo ◽  
Chang-qing Wang
Keyword(s):  
Reliability Analysis ◽  
Lower Limit ◽  
Reliability Index ◽  
Structural Reliability ◽  
Solution Method ◽  
Interval Length ◽  
Structural Safety ◽  
Structural Uncertainty ◽  
Content Type ◽  
Interval Reliability

Purpose – The purpose of this paper is to propose a robust reliability index to characterize the structural safety degree. Design/methodology/approach – On the basis of the interval theory, a new interval reliability analysis method that the structural basic variables are described by the interval lower limit and interval length to characterize the structural uncertainty is proposed in this paper. Findings – A novel structural reliability index solution method is proposed. Besides, both linear and non-linear problem of solving interval non-probabilistic reliability are further discussed in this paper. Originality/value – Based on interval theory, variables are described by interval lower limit and interval length to characterize the structural uncertainty. A novel structural reliability index solution method is proposed.

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