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Advances in Aircraft and Spacecraft Science Volume 4, Number 4, July 2017 , pages 467-486 DOI: https://doi.org/10.12989/aas.2017.4.4.467 |
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A multilevel framework for decomposition-based reliability shape and size optimization |
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Ali Y. Tamijani, Sameer B. Mulani and Rakesh K. Kapania
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| Abstract | ||
| A method for decoupling reliability based design optimization problem into a set of deterministic optimization and performing a reliability analysis is described. The inner reliability analysis and the outer optimization are performed separately in a sequential manner. Since the outer optimizer must perform a large number of iterations to find the optimized shape and size of structure, the computational cost is very high. Therefore, during the course of this research, new multilevel reliability optimization methods are developed that divide the design domain into two sub-spaces to be employed in an iterative procedure: one of the shape design variables, and the other of the size design variables. In each iteration, the probability constraints are converted into equivalent deterministic constraints using reliability analysis and then implemented in the deterministic optimization problem. The framework is first tested on a short column with cross-sectional properties as design variables, the applied loads and the yield stress as random variables. In addition, two cases of curvilinearly stiffened panels subjected to uniform shear and compression in-plane loads, and two cases of curvilinearly stiffened panels subjected to shear and compression loads that vary in linear and quadratic manner are presented. | ||
| Key Words | ||
| reliability analysis; shape optimization; reliability-based design optimization; stiffened panels | ||
| Address | ||
| Ali Y. Tamijani: Department of Aerospace Engineering, Embry-Riddle Aeronautical University, Daytona Beach, Florida, U.S.A. Sameer B. Mulani: Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, Alabama, U.S.A. Rakesh K. Kapania: Department of Aerospace and Ocean Engineering, Virginia Tech, Blacksburg, Virginia, U.S.A. | ||
