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Finding an optimal design for a structural system subject to seismic actions to minimize failure probability, repair costs, and injuries to occupants, significantly contributes to the resilience of buildings in earthquake regions. This research presents a comprehensive framework for the performance-based design optimization of steel structures, incorporating the Performance-Based Earthquake Engineering (PBEE) methodology delineated in FEMA P-58 [1]. A selected set of ground motions, consistent with the seismic hazard intensity of interest, and a nonlinear finite element model, established using OpenSees, enable the assessment of the system's dynamic response. To address the computational complexity related to evaluating the probability of failure of the system during an optimization iteration when using the PBEE methodology for assessing performance, this study introduces metamodeling techniques as a substitute for the original high-fidelity nonlinear finite element model. In particular, Kriging is employed to approximate both the median and standard deviation of the Engineering Demand Parameters (EDPs) in the design domain. The parameters of the Kriging metamodels are derived from nonlinear dynamic analyses performed using the original high-fidelity model and an optimal sampling plan obtained through Latin Hypercube sampling. Under the assumption of a lognormal distribution, the metamodel is then used to generate a large number of simulated demand sets necessary for the Monte Carlo procedure adopted by FEMA P-58 to calculate the distribution of probable losses for any given value of the design variable vector. Additionally, the median and standard deviation of the fragility function modeling collapse are also approximated by a Kriging metamodel, in which the parameters are derived from an Incremental Dynamic Analysis (IDA) for any given value of the design variable vector. The scheme is illustrated in a full-scale case study consisting of the performance-based optimization of the buckling-restrained braces of a steel seismic force-resisting system in terms of expected losses and construction costs. The study demonstrates that the proposed risk-based optimization scheme effectively balances construction costs with expected financial losses from earthquakes, thus enhancing the seismic performance of the system.[1] Applied Technology Council, & National Earthquake Hazards Reduction Program (US). (2012). Seismic performance assessment of buildings. Federal Emergency Management Agency.
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Design Optimization to Minimize Material Usage in Steel Buildings Subjected to Lateral Loads
Abstract This chapter presents a comprehensive approach to optimizing steel usage for reducing the environmental impact of building structures, aligned with sustainable development goals. The study focuses on developing the structural design of members with optimization methods to reduce steel usage, leading to lightweight structural systems while minimizing carbon footprints in the built environment. This study identifies optimum cross-sectional dimensions of structural sections to withstand lateral wind loads. For that purpose, a nonlinear programming solver is used. This solver is robust in finding the minimum of a constrained nonlinear multivariate function. The volume of the structural steel is taken as the objective function to ensure sustainability, while two constraints of demand to capacity indices of structural members as a strength condition and inter-story drift ratio as a serviceability constraint are taken to meet performance criteria, such as safety and cost-effectiveness designing process. The results show that this optimized design tool can effectively reduce the weight of structural steel usage, paving the way to achieve both sustainable and resilient buildings.
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- Award ID(s):
- 2214039
- PAR ID:
- 10616784
- Publisher / Repository:
- Springer Nature Switzerland
- Date Published:
- Page Range / eLocation ID:
- 1529 to 1538
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Book Chapter:
- https://doi.org/10.1007/978-3-031-69626-8_127
