This study presents a methodology for computing stochastic sensitivities with respect to the design variables, which are the mean values of the input correlated random variables. Assuming that an accurate surrogate model is available, the proposed method calculates the component reliability, system reliability, or statistical moments and their sensitivities by applying Monte Carlo simulation to the accurate surrogate model. Since the surrogate model is used, the computational cost for the stochastic sensitivity analysis is affordable compared with the use of actual models. The copula is used to model the joint distribution of the correlated input random variables, and the score function is used to derive the stochastic sensitivities of reliability or statistical moments for the correlated random variables. An important merit of the proposed method is that it does not require the gradients of performance functions, which are known to be erroneous when obtained from the surrogate model, or the transformation from X-space to U-space for reliability analysis. Since no transformation is required and the reliability or statistical moment is calculated in X-space, there is no approximation or restriction in calculating the sensitivities of the reliability or statistical moment. Numerical results indicate that the proposed method can estimate the sensitivities of the reliability or statistical moments very accurately, even when the input random variables are correlated.

1.
Yi
,
K.
,
Choi
,
K. K.
,
Kim
,
N. H.
, and
Botkin
,
M. E.
, 2007, “
Design Sensitivity Analysis and Optimization for Minimizing Springback of Sheet-Formed Part
,”
Int. J. Numer. Methods Eng.
0029-5981,
71
, pp.
1483
1511
.
2.
Youn
,
B. D.
,
Choi
,
K. K.
, and
Yi
,
K.
, 2005, “
Performance Moment Integration (PMI) Method for Quality Assessment in Reliability-Based Robust Optimization
,”
Mech. Based Des. Struct. Mach.
1539-7734,
33
(
2
), pp.
185
213
.
3.
Youn
,
B. D.
,
Choi
,
K. K.
,
Yang
,
R. J.
, and
Gu
,
L.
, 2004, “
Reliability-Based Design Optimization for Crashworthiness of Vehicle Side Impact
,”
Struct. Multidiscip. Optim.
1615-147X,
26
(
3–4
), pp.
272
283
.
4.
Youn
,
B. D.
,
Choi
,
K. K.
, and
Tang
,
J.
, 2005, “
Structural Durability Design Optimization and Its Reliability Assessment
,”
Int. J. Prod. Dev.
,
1
(
3/4
), pp.
383
401
.
5.
Dong
,
J.
,
Choi
,
K. K.
,
Wang
,
A.
,
Zhang
,
W.
, and
Vlahopoulos
,
N.
, 2005, “
Parametric Design Sensitivity Analysis of High Frequency Structural-Acoustic Problems Using Energy Finite Element Method
,”
Int. J. Numer. Methods Eng.
0029-5981,
62
, pp.
83
121
.
6.
Dong
,
J.
,
Choi
,
K. K.
,
Vlahopoulos
,
N.
,
Wang
,
A.
, and
Zhang
,
W.
, 2007, “
Design Sensitivity Analysis and Optimization of High Frequency Radiation Problems Using Energy Finite Element and Energy Boundary Element Methods
,”
AIAA J.
0001-1452,
45
(
6
), pp.
1187
1198
.
7.
Kim
,
N. H.
,
Wang
,
H.
, and
Queipo
,
N. V.
, 2006, “
Adaptive Reduction of Design Variables Using Global Sensitivity in Reliability-Based Optimization
,”
International Journal of Reliability and Safety
,
1
(
1/2
), pp.
102
119
.
8.
Acar
,
E.
, and
Haftka
,
R. T.
, 2007, “
Reliability-Based Aircraft Structural Design Pays, Even With Limited Statistical Data
,”
J. Aircr.
0021-8669,
44
(
3
), pp.
812
823
.
9.
Lee
,
S. H.
,
Chen
,
W.
, and
Kwak
,
B. M.
, 2009, “
Robust Design With Arbitrary Distribution Using Gauss-Type Quadrature Formula
,”
Struct. Multidiscip. Optim.
1615-147X,
39
(
3
), pp.
227
243
.
10.
Yu
,
X.
, and
Du
,
X.
, 2006, “
Reliability-Based Multidisciplinary Optimization for Aircraft Wing Design
,”
Struct. Infrastruct. Eng.
1573-2479,
2
(
3&4
), pp.
277
289
.
11.
Haldar
,
A.
, and
Mahadevan
,
S.
, 2000,
Probability, Reliability and Statistical Methods in Engineering Design
,
Wiley
,
New York
.
12.
Madsen
,
H. O.
,
Krenk
,
S.
, and
Lind
,
N. C.
, 1986,
Methods of Structural Safety
,
Prentice-Hall
,
Englewood Cliffs, NJ
.
13.
Hasofer
,
A. M.
, and
Lind
,
N. C.
, 1974, “
An Exact and Invariant First Order Reliability Format
,”
J. Engrg. Mech. Div.
0044-7951,
100
(
1
), pp.
111
121
.
14.
Ditlevsen
,
O.
, and
Madsen
,
H. O.
, 1996,
Structural Reliability Methods
,
Wiley
,
Chichester, UK
.
15.
Hohenbichler
,
M.
, and
Rackwitz
,
R.
, 1988, “
Improvement of Second-Order Reliability Estimates by Importance Sampling
,”
J. Eng. Mech.
0733-9399,
114
(
12
), pp.
2195
2199
.
16.
Breitung
,
K.
, 1984, “
Asymptotic Approximations for Multinormal Integrals
,”
J. Eng. Mech.
0733-9399,
110
(
3
), pp.
357
366
.
17.
Rahman
,
S.
, and
Wei
,
D.
, 2006, “
A Univariate Approximation at Most Probable Point for Higher-Order Reliability Analysis
,”
Int. J. Solids Struct.
0020-7683,
43
, pp.
2820
2839
.
18.
Wei
,
D.
, 2006, “
A Univariate Decomposition Method for Higher-Order Reliability Analysis and Design Optimization
,” Ph.D. thesis, University of Iowa, Iowa City, IA.
19.
Lee
,
I.
,
Choi
,
K. K.
,
Du
,
L.
, and
Gorsich
,
D.
, 2008, “
Inverse Analysis Method Using MPP-Based Dimension Reduction for Reliability-Based Design Optimization of Nonlinear and Multi-Dimensional Systems
,”
Comput. Methods Appl. Mech. Eng.
0045-7825,
198
(
1
), pp.
14
27
.
20.
Kalsi
,
M.
,
Hacker
,
K.
, and
Lewis
,
K.
, 2001, “
A Comprehensive Robust Design Approach for Decision Trade-Offs in Complex Systems Design
,”
ASME J. Mech. Des.
0161-8458,
123
(
1
), pp.
1
10
.
21.
Su
,
J.
, and
Renaud
,
J. E.
, 1997, “
Automatic Differentiation in Robust Optimization
,”
AIAA J.
0001-1452,
35
(
6
), pp.
1072
1079
.
22.
Rahman
,
S.
, and
Xu
,
H.
, 2004, “
A Univariate Dimension-Reduction Method for Multi-Dimensional Integration in Stochastic Mechanics
,”
Probab. Eng. Mech.
0266-8920,
19
, pp.
393
408
.
23.
Xu
,
H.
, and
Rahman
,
S.
, 2004, “
A Generalized Dimension-Reduction Method for Multi-Dimensional Integration in Stochastic Mechanics
,”
Int. J. Numer. Methods Eng.
0029-5981,
61
(
12
), pp.
1992
2019
.
24.
Lee
,
I.
,
Choi
,
K. K.
,
Du
,
L.
, and
Gorsich
,
D.
, 2008, “
Dimension Reduction Method for Reliability-Based Robust Design Optimization
,”
Comput. Struct.
0045-7949,
86
(
13–14
), pp.
1550
1562
.
25.
Youn
,
B. D.
, and
Choi
,
K. K.
, 2004, “
A New Response Surface Methodology for Reliability-Based Design Optimization
,”
Comput. Struct.
0045-7949,
82
(
2–3
), pp.
241
256
.
26.
Zhang
,
T.
,
Choi
,
K. K.
,
Rahman
,
S.
,
Cho
,
K.
,
Perry
,
B.
,
Shakil
,
M.
, and
Heitka
,
D.
, 2006, “
A Response Surface and Pattern Search Based Hybrid Optimization Method and Application to Microelectronics
,”
Struct. Multidiscip. Optim.
1615-147X,
32
(
4
), pp.
327
345
.
27.
Kim
,
C.
, and
Choi
,
K. K.
, 2008, “
Reliability-Based Design Optimization Using Response Surface Method With Prediction Interval Estimation
,”
ASME J. Mech. Des.
0161-8458,
130
(
12
), p.
121401
.
28.
Simpson
,
T. W.
,
Mauery
,
T. M.
,
Korte
,
J. J.
, and
Mistree
,
F.
, 2001, “
Kriging Models for Global Approximation in Simulation-Based Multidisciplinary Design Optimization
,”
AIAA J.
0001-1452,
39
(
12
), pp.
2233
2241
.
29.
Queipo
,
N. V.
,
Haftka
,
R. T.
,
Shyy
,
W.
,
Goel
,
T.
,
Vaidyanathan
,
R.
, and
Tucker
,
P. K.
, 2005, “
Surrogate-Based Analysis and Optimization
,”
Prog. Aerosp. Sci.
0376-0421,
41
(
1
), pp.
1
28
.
30.
Buranathiti
,
T.
,
Cao
,
J.
,
Chen
,
W.
,
Baghdasaryan
,
L.
, and
Xia
,
Z. C.
, 2004, “
Approaches for Model Validation: Methodology and Illustration on a Sheet Metal Flanging Process
,”
ASME J. Manuf. Sci. Eng.
1087-1357,
126
, pp.
2009
2013
.
31.
Gu
,
L.
,
Yang
,
R. J.
,
Tho
,
C. H.
,
Makowskit
,
M.
,
Faruquet
,
O.
, and
Li
,
Y.
, 2001, “
Optimization and Robustness for Crashworthiness of Side Impact
,”
Int. J. Veh. Des.
0143-3369,
26
(
4
), pp.
348
360
.
32.
Rubinstein
,
R. Y.
, 1981,
Simulation and Monte Carlo Method
,
Wiley
,
New York
.
33.
Noh
,
Y.
,
Choi
,
K. K.
, and
Du
,
L.
, 2009, “
Reliability Based Design Optimization of Problems With Correlated Input Variables Using Copulas
,”
Struct. Multidiscip. Optim.
1615-147X,
38
(
1
), pp.
1
16
.
34.
Noh
,
Y.
,
Choi
,
K. K.
, and
Lee
,
I.
, 2009, “
Reduction of Transformation Ordering Effect in RBDO Using MPP-Based Dimension Reduction Method
,”
AIAA J.
0001-1452,
47
(
4
), pp.
994
1004
.
35.
Noh
,
Y.
,
Choi
,
K. K.
, and
Lee
,
I.
, 2010, “
Identification of Marginal and Joint CDFs Using the Bayesian Method for RBDO
,”
Struct. Multidiscip. Optim.
1615-147X,
40
(
1–6
), pp.
35
51
.
36.
Annis
,
C.
, 2004, “
Probabilistic Life Prediction Isn’t As Easy As It Looks
,”
J. ASTM Int.
1546-962X,
1
(
2
), pp.
3
14
.
37.
Nelsen
,
R. B.
, 1999,
An Introduction to Copulas
,
Springer
,
New York
.
38.
Rubinstein
,
R. Y.
, and
Shapiro
,
A.
, 1993,
Discrete Event Systems––Sensitivity Analysis and Stochastic Optimization by the Score Function Method
,
Wiley
,
New York
.
39.
Rahman
,
S.
, 2009, “
Stochastic Sensitivity Analysis by Dimensional Decomposition and Score Functions
,”
Probab. Eng. Mech.
0266-8920,
24
, pp.
278
287
.
40.
Zhao
,
L.
,
Choi
,
K. K.
,
Lee
,
I.
, and
Gorsich
,
D.
, 2010, “
A Metamodeling Method Using Dynamic Kriging and Sequential Sampling
,”
The 13th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference
, Fort Worth, TX, Sept. 13–15.
41.
McDonald
,
M.
, and
Mahadevan
,
S.
, 2008, “
Design Optimization With System-Level Reliability Constraints
,”
ASME J. Mech. Des.
0161-8458,
130
(
2
), p.
021403
.
42.
Browder
,
A.
, 1996,
Mathematical Analysis: An Introduction
,
Springer-Verlag
,
New York
.
43.
Hijab
,
O.
, 1997,
Introduction to Calculus and Classical Analysis
,
Springer-Verlag
,
New York
.
44.
Lee
,
I.
,
Choi
,
K. K.
, and
Zhao
,
L.
, 2010, “
Sampling-Based RBDO Using the Dynamic Kriging (D-Kriging) Method and Stochastic Sensitivity Analysis
,”
The 13th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference
, Fort Worth, TX, Sept. 13–15.
45.
Viana
,
A. C. F.
,
Haftka
,
R. T.
, and
Steffen
,
V.
, 2009, “
Multiple Surrogates: How Cross-Validation Errors Can Help Us to Obtain the Best Predictor
,”
Struct. Multidiscip. Optim.
1615-147X,
39
(
4
), pp.
439
457
.
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