TY - GEN

T1 - Optimal design of nonlinear structures under evolutionary stochastic earthquake excitations

AU - Mitseas, Ioannis P.

AU - Kougioumtzoglou, Ioannis A.

AU - Beer, Michael

PY - 2014

Y1 - 2014

N2 - A novel methodology for optimal structural system design considering life cycle seismic loss estimation is developed. Specifically, a performance-based multi-objective design optimization framework is proposed for nonlinear/hysteretic multi-degree-of-freedom (MDOF) structural systems under evolutionary stochastic earthquake excitations. The core of the proposed framework is a recently developed efficient approximate analytical system response determination technique which can readily handle cases of nonlinear/hysteretic systems and of non-stationary stochastic excitations of arbitrary evolutionary power spectrum forms. Thus, the non-stationary response amplitude probability density functions (PDFs) of the inter-storey drift ratios (IDRs) are efficiently determined, circumventing computationally intensive Monte Carlo simulations. Note that the proposed framework allows for making explicit the relationship between the stochastic earthquake excitations, the non-stationary response amplitude PDFs of the IDRs, and the expected value of the life cycle seismic losses. In this regard, an efficient determination of Pareto optimal solutions is implemented. Further, the multi-objective optimization problem is solved by employing a Genetic Algorithm based approach to determine Pareto optimal solutions, which is specifically tailored to meet the characteristics of the problem under consideration. Hence, various possible solutions including the design that best represents the outcome that the designer considers potentially satisfactory are obtained. An illustrative numerical example, comprising the versatile Bouc-Wen (hysteretic) model is considered to demonstrate the efficiency and robustness of the proposed methodology.

AB - A novel methodology for optimal structural system design considering life cycle seismic loss estimation is developed. Specifically, a performance-based multi-objective design optimization framework is proposed for nonlinear/hysteretic multi-degree-of-freedom (MDOF) structural systems under evolutionary stochastic earthquake excitations. The core of the proposed framework is a recently developed efficient approximate analytical system response determination technique which can readily handle cases of nonlinear/hysteretic systems and of non-stationary stochastic excitations of arbitrary evolutionary power spectrum forms. Thus, the non-stationary response amplitude probability density functions (PDFs) of the inter-storey drift ratios (IDRs) are efficiently determined, circumventing computationally intensive Monte Carlo simulations. Note that the proposed framework allows for making explicit the relationship between the stochastic earthquake excitations, the non-stationary response amplitude PDFs of the IDRs, and the expected value of the life cycle seismic losses. In this regard, an efficient determination of Pareto optimal solutions is implemented. Further, the multi-objective optimization problem is solved by employing a Genetic Algorithm based approach to determine Pareto optimal solutions, which is specifically tailored to meet the characteristics of the problem under consideration. Hence, various possible solutions including the design that best represents the outcome that the designer considers potentially satisfactory are obtained. An illustrative numerical example, comprising the versatile Bouc-Wen (hysteretic) model is considered to demonstrate the efficiency and robustness of the proposed methodology.

KW - Evolutionary stochastic excitations

KW - Hysteretic systems

KW - Life-cycle loss estimation

KW - Multi-objective optimization

KW - Statistical linearization

KW - Stochastic dynamics

UR - http://www.scopus.com/inward/record.url?scp=84911904134&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:84911904134

SP - 2213

EP - 2233

BT - OPT-i 2014 - 1st International Conference on Engineering and Applied Sciences Optimization, Proceedings

A2 - Lagaros, N. D.

A2 - Karlaftis, Matthew G.

A2 - Papadrakakis, M.

T2 - 1st International Conference on Engineering and Applied Sciences Optimization, OPT-i 2014

Y2 - 4 June 2014 through 6 June 2014

ER -