Multi-objective Evolutionary Optimization of Passive Energy Dissipation Systems under Seismic Loading

With the conceptual development of performance-based design, the earthquake engineering community has begun to recognize the importance of controlling both interstory drifts and absolute floor accelerations. However, these often present conflicting requirements for design. In this paper, we present a multi-objective genetic algorithm to address this conflict by identifying a Pareto front of optimal solutions. This provides decision makers with the information needed to understand the tradeoffs between the two objectives of minimizing drift and acceleration. Furthermore, the multi-objective approach allows broad comparisons between different types of structural response control strategies and devices. Here we focus on several passive energy dissipation systems, with particular emphasis on nonlinear viscous fluid dampers. In addition to presenting the overall multi-objective framework, we consider an example of a five story steel building and evolve some interesting Pareto front structural designs.