Mariantonieta Gutierrez Soto, PhD
Assistant Professor, The University of Kentucky
The protection of infrastructure is a critical and complex issue faced by civil engineers. Earthquakes are especially unpredictable and pose a great threat to critical infrastructure. To tackle this problem, the latest innovation is the development of smart structures. Smart structures have technology installed to dampen the vibration caused by forces of nature. The goal is to develop a new generation of smart structures equipped with sensors and control devices that can react in real-time during an earthquake. Structural control methods have been subject of significant research, yet they still face limitations that this research overcomes by introducing the concepts of decentralized control, agent technology, and replicator dynamics.
This presentation consists of four parts. In Part I, three ideas are introduced for vibration control of smart structures: agent technology, replicator dynamics from evolutionary game theory, and energy minimization. Two new control algorithms are presented: 1) a single-agent Centralized Replicator Controller (CRC) and a decentralized Multi-Agent Replicator Controller (MARC) for real-time vibration control of smart structures. The use of agents and a decentralized approach enhances the robustness of the entire vibration control system. The proposed control methodologies are applied to vibration control of a 3-story steel frame and a 20-story steel benchmark structure subjected to two sets of seismic loadings: historic earthquake accelerograms and artificial earthquakes and compared with the corresponding centralized and decentralized conventional control algorithms. In Part II, the aforementioned control algorithms are integrated with a multi-objective optimization algorithm in order to find Pareto optimal values for replicator dynamics parameters with the goal of achieving maximum structural performance with minimum energy consumption. The patented neural dynamic model of Adeli and Park is used to solve the multi-objective optimization problem. Vibration control of irregular structures subjected to earthquake excitations is a complex civil engineering problem with associated torsional vibrations. In Part III, the replicator dynamics concepts are adapted for active/semi-active control of multi-story irregular base-isolated structures. The control algorithm is evaluated using a 3D base-isolated benchmark structure subjected to major historical earthquakes. In part IV, the idea of combining the conventional base isolation with an active or semi-active control system to create smart bridge structures. A novel control algorithm based on game theory and replicator dynamics is employed for hybrid vibration control of highway bridge structures equipped with both a passive isolation system and semi-active control devices subjected to earthquake loadings. The efficacy of the model is demonstrated by application to a benchmark example based on interstate 91/5 overcrossing highway bridge in southern California subjected to near-field historical earthquake excitations. Substantial reduction in both mid-span displacement and deck acceleration is achieved compared with the conventional base-isolated bridge. This research is intended to lay the foundation for a new generation of smart and sustainable building and bridge structures.
Thank you for your submission.