Implementable Bio-Inspired Passive Negative Spring Actuator for Full-Scale Structural Control under Seismic Excitation

A bio-inspired passive negative spring actuator inspired by an energy-dissipating mechanism called sacrificial bonds and hidden length is designed, fabricated and implemented in a test case of a three-story structural model for testing its performance and demonstrating the effectiveness as a passive controller. Specifically, a unique design of a negative spring actuator is developed and combined with a viscous damper to exhibit aspects of the force-displacement relation of negative sacrificial bonds and hidden length. This novel actuator can output a unique force-displacement profile, capable of large control forces, making the bio-inspired passive actuator practical for implementation in real structures. Results obtained from numerical simulation were validated experimentally on a model structure. The results showed that the bio-inspired passive negative spring actuator has comparable structural control performance to state-of-the-art semiactive actuators. Therefore, the actuator could be a practical, low-cost, and effective passive-control device for use in civil, mechanical, aerospace, and other structures. (C) 2015 American Society of Civil Engineers.