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.

Reliability analysis for a hypersonic aircraft’s wing spar

2019 ◽  
Vol 91 (4) ◽  
pp. 549-557
Author(s):  
Yuhui Wang ◽  
Peng Shao ◽  
Qingxian Wu ◽  
Mou Chen
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Strength Degradation ◽  
Structural Safety ◽  
Engineering Practice ◽  
Flight Safety ◽  
Content Type ◽  
Hypersonic Aircraft ◽  
Analysis Scheme ◽  
Wing Spar

Purpose This paper aims to present a novel structural reliability analysis scheme with considering the structural strength degradation for the wing spar of a generic hypersonic aircraft to guarantee flight safety and structural reliability. Design/methodology/approach A logarithmic model with strength degradation for the wing spar is constructed, and a reliability model of the wing spar is established based on stress-strength interference theory and total probability theorem. Findings It is demonstrated that the proposed reliability analysis scheme can obtain more accurate structural reliability and failure results for the wing spar, and the strength degradation cannot be neglected. Furthermore, the obtained results will provide an important reference for the structural safety of hypersonic aircraft. Research limitations/implications The proposed reliability analysis scheme has not implemented in actual flight, as all the simulations are conducted according to the actual experiment data. Practical implications The proposed reliability analysis scheme can solve the structural life problem of the wing spar for hypersonic aircraft and meet engineering practice requirements, and it also provides an important reference to guarantee the flight safety and structural reliability for hypersonic aircraft. Originality/value To describe the damage evolution more accurately, with consideration of strength degradation, flight dynamics and material characteristics of the hypersonic aircraft, the stress-strength interference method is first applied to analyze the structural reliability of the wing spar for the hypersonic aircraft. The proposed analysis scheme is implemented on the dynamic model of the hypersonic aircraft, and the simulation demonstrates that a more reasonable reliability result can be achieved.

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.

Improved bat algorithm for structural reliability assessment: application and challenges

2016 ◽  
Vol 12 (2) ◽  
pp. 218-253 ◽  
Author(s):  
Asma Chakri ◽  
Rabia Khelif ◽  
Mohamed Benouaret
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Structural Reliability ◽  
Limit State ◽  
Computing Time ◽  
Bat Algorithm ◽  
Normal Space ◽  
Content Type ◽  
Reliability Method ◽  
Adaptive Penalty

Purpose – The first order reliability method requires optimization algorithms to find the minimum distance from the origin to the limit state surface in the normal space. The purpose of this paper is to develop an improved version of the new metaheuristic algorithm inspired from echolocation behaviour of bats, namely, the bat algorithm (BA) dedicated to perform structural reliability analysis. Design/methodology/approach – Modifications have been embedded to the standard BA to enhance its efficiency, robustness and reliability. In addition, a new adaptive penalty equation dedicated to solve the problem of the determination of the reliability index and a proposition on the limit state formulation are presented. Findings – The comparisons between the improved bat algorithm (iBA) presented in this paper and other standard algorithms on benchmark functions show that the iBA is highly efficient, and the application to structural reliability problems such as the reliability analysis of overhead crane girder proves that results obtained with iBA are highly reliable. Originality/value – A new iBA and an adaptive penalty equation for handling equality constraint are developed to determine the reliability index. In addition, the low computing time and the ease implementation of this method present great advantages from the engineering viewpoint.

scholarly journals Hermite polynomial normal transformation for structural reliability analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jinsheng Wang ◽  
Muhannad Aldosary ◽  
Song Cen ◽  
Chenfeng Li
Keyword(s):  
Reliability Analysis ◽  
Hermite Polynomial ◽  
Structural Reliability ◽  
Hermite Polynomials ◽  
Random Variables ◽  
Transformation Method ◽  
Statistical Moments ◽  
Content Type ◽  
Structural Reliability Analysis ◽  
Normal Transformation

Purpose Normal transformation is often required in structural reliability analysis to convert the non-normal random variables into independent standard normal variables. The existing normal transformation techniques, for example, Rosenblatt transformation and Nataf transformation, usually require the joint probability density function (PDF) and/or marginal PDFs of non-normal random variables. In practical problems, however, the joint PDF and marginal PDFs are often unknown due to the lack of data while the statistical information is much easier to be expressed in terms of statistical moments and correlation coefficients. This study aims to address this issue, by presenting an alternative normal transformation method that does not require PDFs of the input random variables. Design/methodology/approach The new approach, namely, the Hermite polynomial normal transformation, expresses the normal transformation function in terms of Hermite polynomials and it works with both uncorrelated and correlated random variables. Its application in structural reliability analysis using different methods is thoroughly investigated via a number of carefully designed comparison studies. Findings Comprehensive comparisons are conducted to examine the performance of the proposed Hermite polynomial normal transformation scheme. The results show that the presented approach has comparable accuracy to previous methods and can be obtained in closed-form. Moreover, the new scheme only requires the first four statistical moments and/or the correlation coefficients between random variables, which greatly widen the applicability of normal transformations in practical problems. Originality/value This study interprets the classical polynomial normal transformation method in terms of Hermite polynomials, namely, Hermite polynomial normal transformation, to convert uncorrelated/correlated random variables into standard normal random variables. The new scheme only requires the first four statistical moments to operate, making it particularly suitable for problems that are constraint by limited data. Besides, the extension to correlated cases can easily be achieved with the introducing of the Hermite polynomials. Compared to existing methods, the new scheme is cheap to compute and delivers comparable accuracy.

scholarly journals Reliability Analysis of St. Barbara’s Church in Otovice

2020 ◽  
Vol 868 ◽  
pp. 166-172
Author(s):  
Chandrashekhar Mahato ◽  
Pavel Kuklík
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Probabilistic Approach ◽  
Probability Of Failure ◽  
Structural Safety ◽  
Site Condition ◽  
Baroque Architecture ◽  
Material Parameters ◽  
Safety And Stability ◽  
Present Site

The Churches of the Broumov region are well known for their unique baroque architecture, distinct shapes, sizes, and constitutes an integral part of the Czech cultural heritage. The St. Barbara’s Church that has been studied in this article, is in the Otovice village of Broumov. It was built in the year 1726 by Bavarian architects Christoph Dientzenhofer and Kilian Ignaz and is significant because of its religious, artistic and historic values. The main objective of this study is to evaluate the structural safety and stability of St. Barbara’s Church based on a probabilistic approach. A deterministic assessment of the structure is carried out and the results are assessed concerning the present site condition. Depending upon the observed damages, a condition for failure is defined for the structure. The uncertainties in the material parameters are considered and reliability analysis is performed to determine the reliability index, probability of failure and influence of different material parameters in the structural stability.

Reliability-based design criteria for timber bridges in Ontario

1986 ◽  
Vol 13 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Andrzej S. Nowak ◽  
Raymond J. Taylor
Keyword(s):  
Reliability Index ◽  
Structural Reliability ◽  
Structural Safety ◽  
Design Code ◽  
Bridge Design ◽  
Limit States ◽  
Acceptance Criterion ◽  
Reliability Based Design ◽  
Load And Resistance Factor ◽  
Timber Bridges

The new Ontario Highway Bridge Design Code (OHBDC) is based on limit states theory and therefore uses a load and resistance factor format. This paper deals with the development of the basis for the timber bridge design provisions (OHBDC). Three structural systems are considered: sawn timber stringers, laminated nailed decks, and prestressed laminated decks. The latter system has been successfully used in Ontario for the last 7 years.The acceptance criterion in calculation of load and resistance factors is structural reliability. It is required that bridges designed using the new code must have a reliability equal to or greater than a preselected target value. Reliability is measured in terms of the reliability index. The safety analysis is performed for a structural system rather than for individual members. The live load model was developed on the basis of available truck survey data. Material properties are based on extensive in-grade test results. Numerical examples are included to demonstrate the presented approach. Key words: bridge deck, design code, prestressed timber, reliability, reliability index, stringers, structural safety, timber bridges.

scholarly journals A Sensitivity-Based Approach for Reliability Analysis of Randomly Excited Structures With Interval Axial Stiffness

2020 ◽  
Vol 6 (4) ◽  
Author(s):  
Alba Sofi ◽  
Giuseppe Muscolino ◽  
Filippo Giunta
Keyword(s):  
Reliability Analysis ◽  
Interval Analysis ◽  
Structural Reliability ◽  
Reliability Function ◽  
Extreme Value ◽  
Axial Stiffness ◽  
Engineering Practice ◽  
Stress Process ◽  
Rational Series ◽  
Interval Reliability

Abstract Reliability assessment of linear discretized structures with interval parameters subjected to stationary Gaussian multicorrelated random excitation is addressed. The interval reliability function for the extreme value stress process is evaluated under the Poisson assumption of independent up-crossing of a critical threshold. Within the interval framework, the range of stress-related quantities may be significantly overestimated as a consequence of the so-called dependency phenomenon, which arises due to the inability of the classical interval analysis to treat multiple occurrences of the same interval variables as dependent ones. To limit undesirable conservatism in the context of interval reliability analysis, a novel sensitivity-based procedure relying on a combination of the interval rational series expansion and the improved interval analysis via extra unitary interval is proposed. This procedure allows us to detect suitable combinations of the endpoints of the uncertain parameters which yield accurate estimates of the lower bound and upper bound of the interval reliability function for the extreme value stress process. Furthermore, sensitivity analysis enables to identify the most influential parameters on structural reliability. A numerical application is presented to demonstrate the accuracy and efficiency of the proposed method as well as its usefulness in view of decision-making in engineering practice.

STRUCTURAL RELIABILITY ANALYSIS OF STEEL TRUSS ELEMENTS ON BUCKLING USING PBOX APPROACH

2021 ◽  
pp. 45-53
Author(s):  
A.A. Solovyova ◽  
◽  
S.A. Solovyov ◽  
Keyword(s):  
Reliability Analysis ◽  
Structural Reliability ◽  
Statistical Data ◽  
Limit State ◽  
Random Variables ◽  
Distribution Functions ◽  
Structural Safety ◽  
Random Load ◽  
Load Models ◽  
Steel Trusses

Abstract. The reliability of load-bearing structural elements is one of the indicators of structural safety. The article presents methods for steel trusses bars reliability analysis according to the buckling criterion using p-boxes. A p-box consists of two boundary probability distribution functions that form the area of possible distribution functions. Such model used for modeling random variables in conditions of incomplete statistical data by quantity or quality. An algorithm for summing p-boxes of random load models is demonstrated on the example of a probabilistic estimate of the force in the truss bar. The result of reliability analysis using p-boxes is presented in interval form. The use of p-boxes makes it possible to obtain a more cautious assessment of reliability in case of incomplete statistical data. To increase the informativity of the reliability analysis result, it is necessary to obtain more statistical data about random variables in design mathematical models of limit state, which will allow forming p-boxes with narrower boundary distribution functions.

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.

Interval Reliability Analysis of Parameters of Section of Main Beam

2014 ◽  
Vol 644-650 ◽  
pp. 4991-4994
Author(s):  
Jian Fang Zhou ◽  
Guang Ran Lu
Keyword(s):  
Monte Carlo ◽  
Reliability Analysis ◽  
Optimization Algorithm ◽  
Reliability Index ◽  
Main Beam ◽  
One Dimensional ◽  
Advantages And Disadvantages ◽  
Interval Reliability ◽  
Dimensional Optimization

In the calculation of the reliability of hydraulic, due to extensive uncertainties, there are lots of errors in probabilistic reliability analysis. In this paper, by comparing the non-probabilistic reliability index of different function, we get the advantages and disadvantages of one-dimensional optimization algorithm and method of Monte Carlo, and compare the functions of each variable of main beam to obtain the influence of the precision of the variables.

Sign in / Sign up

Export Citation Format

Share Document