Lightly-damped rolling isolation systems are being used to protect mission-critical equipment from shock and vibration hazards. This project will develop experimentally-validated models and seismic qualification guidelines for rolling isolation systems incorporating passive and controllable damping treatments. The passive damping treatments will use elastomeric composites and will be modeled and designed using a combination of experimental and semi-analytic methods. The controllable friction damping will feature magnetically-controlled friction damping incorporating novel magnetically-permeable polymers with high friction coefficients and will be assessed using methods of nonlinear optimal control. The seismic qualification guidelines will be based on methods of probabilistic seismic hazard analysis and will feature detailed statistical models of uniform-hazard earthquake ground motions. This project will resolve persistent issues regarding displacement capacity, damping levels, damping mechanisms, and response-control pertaining to the protection of equipment from earthquake hazards.
These results will enable engineers to design and qualify rolling isolation systems to achieve a desired level of hazard mitigation for specific geographic regions and general installation environments. Ultimately, this research will contribute to the mitigation of seismic hazards for facilities that must operate during and after major earthquakes and will thereby improve response and recovery operations. Technology developed in this project will transfer to practice through the development of an industrial consortium and the training of current and future professionals. Graduate students involved in this research will learn and apply advanced methods in dynamics and risk analysis. Undergraduates and high school students will work together to learn methods of experimental dynamics and model validation. The project will undertake the creation of substantial web-based laboratories through which students of any level may investigate the behavior of rolling isolation systems on-line, through physical and numerical simulations.