It has been widely recognized that engineering design should account for the stochastic nature of random parameters in engineered systems. In this research area, the techniques of reliability analysis and design optimization are integrated to develop reliability-based design methodologies that offer probabilistic approaches to engineering design. Reliability-based design attempts to find the optimum design that minimizes the cost and satisfies a target reliability, while accounting for various sources of uncertainty. In the design space, reliability-based design pushes the deterministic optimum design back to the reliable region to create a safety margin that accommodates the uncertainty in parameters and design variables. My research has been focused on developing computationally efficient methods for uncertainty propagation, and component and system reliability analyses for complex engineered systems that involve expensive simulations and/or large dimensions. My research aims to develop theoretically sound, and self-consistent methods to support engineering design under uncertainty.

I have investigated the stochastic spectral and collocation methods to reduce the number of function evaluations required by reliability analysis. The investigation has led to the development of several computationally efficient methods that could drastically reduce the cost of reliability analysis and significantly broaden the application of reliability-based design in modern complex systems. These methods can be used by design engineers in private industries, government, and academic fields to obtain the optimal design for various engineered systems such as vehicles, space shuttles, aircraft, and ships.

Software code: The stochastic response surface method (SRSM) toolkit was developed that integrates univariate dimension reduction (UDR) with cubic spline interpolation to build a stochastic response surface. The toolkit provides an efficient uncertainty propagation strategy that promotes the wide-scale application of engineering design under uncertainty.

Publications

1. Hu C., Youn B.D. and Wang P., “Probabilistic Engineering Analysis and Design,” Accepted for Publication, Springer Series in Reliability Engineering, Springer, 2014.
2. Hu C., Wang P., and Youn B.D., “Advances in System Reliability Analysis under Uncertainty,” Chapter 9 in Numerical Methods for Reliability and Safety Assessment: Multiscale and Multiphysics Systems, Springer, 2014. [ Link ]
3. Hu C., and Youn B.D., “An Adaptive Dimension Decomposition and Reselection Method for Reliability Analysis,” Structural and Multidisciplinary Optimization, v47, n3, p423–440, 2013. [ DOI | PDF ]
4. Xi Z., Hu C., and Youn B.D., “A Comparative Study of Probability Estimation Methods for Reliability Analysis,” Structural and Multidisciplinary Optimization, v45, n1, p33‒52, 2012. [ DOI | PDF ]
5. Hu C., and Youn B.D., “An Asymmetric Dimension-Adaptive Tensor-Product Method for Reliability Analysis,” Structural Safety, v33, n3, p218‒231, 2011. [ DOI | PDF ]
6. Hu C., and Youn B.D., “Adaptive-Sparse Polynomial Chaos Expansion for Reliability Analysis and Design of Complex Engineering Systems,” Structural and Multidisciplinary Optimization, v43, n3, p419‒442, 2011. [ DOI | PDF ]
7. Wang P., Hu C., and Youn B.D., “A Generalized Complementary Intersection Method for System Reliability Analysis and Design,” Journal of Mechanical Design, v133, n7, 071003(13), 2011. [ DOI | PDF ]
8. Youn B.D., Hu C., Wang P., and Yoon J.T., “Resilience Allocation for Resilient Engineered System Design,” Journal of Institute of Control, Robotics and Systems, v17, n11, p1082-1089, 2011. [ DOI ]
9. Xi Z., Youn B.D., and Hu C., “Random Field Characterization Considering Statistical Dependence for Probability Analysis and Design,” Journal of Mechanical Design, v132, n10, 101008(12), 2010. [ DOI | PDF ]
10. Hu C., and Youn B.D., “An Asymmetric Dimension-Adaptive Tensor-Product Method for Reliability Analysis,” ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE), Aug 28-31 2011, Washington, DC. (Conducted presentation)
11. Hu C., and Youn B.D., “An Asymmetric Dimension-Adaptive Tensor-Product Method for Reliability Analysis,” AIAA 2010-2109, 51th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Apr 12-15 2010, Orlando, FL. (Conducted presentation)
12. Xi Z., Youn B.D., and Hu C., “Effective Random Field Characterization Considering Statistical Dependence for Probability Analysis and Design,” ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE), Aug 15-18 2010, Montreal, Quebec, Canada.
13. Hu C., and Youn B.D., “Adaptive-Sparse Polynomial Chaos Expansion for Reliability Analysis and Design of Complex Engineering Systems,” ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE), Aug 30-Sep 2 2009, San Diego, CA. (Conducted presentation)
14. Hu C., and Youn B.D., “Adaptive-Sparse Polynomial Chaos Expansion for Reliability Analysis and Design of Complex Engineering Systems,” ASME International Design Engineering Technical Conferences & Computers and Information in Engineering Conference (IDETC/CIE), Aug 30-Sep 2 2009, San Diego, CA. (Conducted presentation)
15. Wang P., Youn B.D., and Hu C., “A Generalized Complementary Intersection Method (CIM) for System Reliability Analysis,” AIAA 2009-2109, 50th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, May 4-7 2009, Palm Springs, CA.