Modeling of Epistemic Uncertainty in Reliability Analysis of Structures Using a Robust Genetic Algorithm

Document Type : Research Paper

Authors

Department of Civil Engineering, University of Sistan and Baluchestan, Zahedan, Iran

Abstract

In this paper the fuzzy structural reliability index was determined through modeling epistemic uncertainty arising from ambiguity in statistical parameters of random variables. The First Order Reliability Method (FORM) has been used and a robust genetic algorithm in the alpha level optimization method has been proposed for the determination of the fuzzy reliability index. The sensitivity level of fuzzy response due to the introduced epistemic uncertainty was also measured using the modified criterion of Shannon entropy. By introducing bounds of uncertainty, the fuzzy response obtained from the proposed method presented more realistic estimation of the structure reliability compared to classic methods. This uncertainty interval is of special importance in concrete structures since the quality of production and implementation of concrete varies in different cross sections in reality. The proposed method is implementable in reliability problems in which most of random variables are fuzzy sets and in problems containing non-linear limit state functions and provides a precise acceptable response. The capabilities of the proposed method were demonstrated using different examples. The results indicated the accuracy of the proposed method and showed that classical methods like FORM cover only special case of the proposed method.

Keywords


[1] G. Alefeld and J. Hertzberger, Introduction to interval computations, Academic Press, New
York, 1983.
[2] D. K. Armen and D. Taleen, Multiple design points in rst and second-order reliability,
Journal of Structural Safety, 20 (1998), 37-49.
[3] M. S. Arumugam, M. V. C. Rao and R. Palaniappan, New hybrid genetic operators for real
coded genetic algorithm to compute optimal control of a class of hybrid systems, Journal of
Applied Soft Computing, 6 (2005), 38-52.
[4] S. K. Au and J. L. Beck,Estimation of small failure probabilities in high dimension by subset
simulation, Journal of Probabilistic Engineering Mechanics, 16(4) (2001), 263-277.
[5] B. M. Ayyub and R. H. McCuen, Probability, statistics, and reliability for engineers and
scientists, 2nd Ed. Chapman Hall/CRC, Boca Raton, Fla, 2003.
[6] Y. Ben-Haim, Robust reliability in mechanical sciences, Springer, Berlin, 1996.
[7] K. Breitung, Asymptotic approximations for multinormal integrals, Journal of Engineering
Mechanics ASCE, 110(3) (1984), 357-366.
[8] A. DerKiureghian and O. Ditlevsen, Aleatory or epistemic? Does it matter?, Journal of
Structural Safety, 31 (2009), 105-112.
[9] W. Dong and H. Shah, Vertex method for computing functions on fuzzy variables, Journal of
Fuzzy Sets and Systems, 24(1) (1978), 65-78.
[10] A. H Elhewy, E. Mesbahi and Y. Pu, Reliability analysis of structures using neural network
method, Journal of Probability Engineering Mechanics, 21 (2006), 44-53.
[11] S. Freitag, W. Graf and M. Kaliske, A material description based on recurrent neural networks
for fuzzy data and its application within the nite element method, Journal of Computers
and Structures, 124 (2013), 29-37.
[12] M. Giuseppe and Q. Giuseppe, A new possibilistic reliability index de nition, Journal of
ActaMechanica, 210 (2010), 291-303.
[13] D. E. Goldberg, Genetic Algorithms in search, optimization and machine learning, Addison-
Wesley, 1989.
[14] F. Grooteman, Adaptive radial-based importance sampling method for structural reliability,
Journal of Structural Safety, 30(6) (2008), 533-542.
[15] J. W. Hall and J. Lawry, Fuzzy label methods for constructing imprecise limit state functions,
Journal of Structural Safety, 25(4) (2003), 317-341.
[16] M. Hanss and S. Turrin, A fuzzy-based approach to comprehensive modeling and analysis of
systems with epistemic uncertainties, Journal of Structural Safety, 32(6) (2010), 433-441.
[17] A. M. Hasofer and N. C. Lind, Exact and invariant second moment code format, Journal of
Engineering Mechanics ASCE, 100 (1974), 111-121.
[18] J. C. Helton and W. L. Oberkampf, alternative representations of epistemic uncertainty,
Journal of Reliability Engineering and System Safety, 85(1-3) (2004), 1-10.
[19] J. E. Hurtado and D. A. Alvarez,Neural network-based reliability analysis: a comparative
study, Journal of Computer Methods in Applied Mechanics and Engineering, 191(1-2)
(2001), 113-132.
[20] J. E. Hurtado, D. A. Alvarez and J. Ramirez, Fuzzy structural analysis based on fundamental
reliability concepts, Journal of Computers and Structures, 112 (2012), 183-192.
[21] P. Inseok and V. Ramana V Grandhi, Quanti cation of model-form and parametric uncer-
tainty using evidence theory, Journal of Structural Safety, 39 (2012), 44-51.
[22] F. Jalayer, I. Iervolino and G. Manfredi, Structural modeling uncertainties and their in
uence
on seismic assessment of existing RC structures, Journal of Structural Safety, 32(3) (2010),
220-228.
[23] H. Jinsong and D. V. Griths, Observations on FORM in a simple geomechanics example,
Journal of Structural Safety, 33(1) (2011), 115-119.
[24] S. D. Koduru and T. Haukaas, Feasibility of FORM in nite element reliability analysis,
Journal of Structural Safety, 32(2) (2010), 145-153.
[25] H. Kwakernaak, Fuzzy random variables - I. De nitions and Theorems, Journal of Informa-
tion Science, 15 (1978), 1-29.
[26] H. Kwakernaak, Fuzzy random variables - II.Algorithms and Examples for the Discrete Case,
Journal of Information Science, 17 (1979), 253-278.
[27] H. O. Madsen, S. Krenk and N. C. Lind, Methods of structural safety, New York: Dover
Publications, 2006.
[28] F. Massa F, K. Run, T. Tison and B. Lallemand, A complete method for ecient fuzzy
modal analysis, Journal of Sound and Vibration, 309(1-2) (2008), 63-85.
[29] R. E. Melchers, Structural reliability analysis and prediction, 2nd Ed. Chichester John Wiley
and Sons, 1999.
[30] R. E. Melchers, M. Ahammed and C. Middleton, FORM for discontinuous and truncated
probability density functions, Journal of Structural Safety, 25(3) (2003), 305-313.
[31] B. Moller and M. Beer, Fuzzy randomness - uncertainty in civil engineering and computa-
tional mechanics, Springer Verlag, Berlin, 2004.
[32] B. Moller, W. Graf and M. Beer, Fuzzy structural analysis using -level optimization, Journal
of Computational Mechanics, 26(6) (2000), 547-565.
[33] B. Moller, W. Graf, M. Beer and R. Schneider,Safety assessment of structures in view of
fuzzy randomness, Journal of Computers and Structeurs, 81 (2003), 1567-1582.
[34] A. S. Nowak and K. R. Collins, Reliability of structures, McGraw-Hill, 2000.
[35] M. V. Rama Rao, A. Pownuk, S. Vandewalle and D. Moens, Transient response of structures
with uncertain structural parameters, Journal of Structural Safety, 32 (2010), 449-460.
[36] M. Rashki, M. Miri and M. AzhdaryMoghaddam, A new ecient simulation method to
approximate the probability of failure and most probable point, Journal of Structural Safety,
39 (2012), 22-29.
[37] T. V. Santosh, R. K. Saraf, A. K. Ghosh and H. S. Kushwaha, Optimum step length selection
rule in modi ed HL-RF method for structural reliability International Journal of Pressure
Vessels and Piping, 83 (2006), 742-748.
[38] A. Sera nska, M. Kaliske, C. Zopf and W. Graf, A multi-objective optimization approach
with consideration of fuzzy variables applied to structural tire design, Journal of Computers
and Structures, 116(1), (2013), 9-17.
[39] M. C. Tae and C. L. Byung, Reliability-based design optimization using convex linearization
and sequential optimization and reliability assessment method, Journal of Structural Safety,
33(1) (2011), 42-50.
[40] J. R. Timothy, (2010), Fuzzy logic with engineering applications, 3rd Ed. Publisher Wiley,
2010.
[41] G. Wei, S. Chongmin and TL. Francis, Probabilistic interval analysis for structures with
uncertainty, Journal of Structural Safety, 32(3) (2010), 191-199.
[42] M. William and M. Bulleit, Uncertainty in structural engineering, Journal of Practice Peri-
odical on Structural Design and Construction, 13(1) (2008), 24-30.
[43] L. N. Xing, Y. W. Chen, K. W. Yang, F. Hou, S. Xue and P. C. Huai, A hybrid approach
combining an improved genetic algorithm and optimization strategies for the asymmetric
traveling salesman problem, Journal of Engineering Applications of Arti cial Intelligence, 21
(2008), 1370-1380.
[44] L. A. Zadeh, Fuzzy sets, Journal of Information Control, 8(3) (1965), 338-553.
[45] H. Zhang, Interval importance sampling method for nite element-based structural reliability
assessment under parameter uncertainties, Journal of Structural Safety, 38 (2012), 1-10.
[46] M. Q. Zhang, M. Beer, S. T. Quek and Y. S. Choo, Comparison of uncertainty models
in reliability analysis of o shore structures under marine corrosion, Journal of Structural
Safety, 32 (2010), 425-432.
[47] Y. G. Zhao and T. Ono, Moment methods for structural reliability, Journal of Structural
Safety, 23 (2001), 47-75.
[48] H. J. Zimmermann, Fuzzy set theory and its applications, Kluwer Academic Publishers, Lon-
don, 1992.