Simulations help in studying earthquake dampers for structures

said Dyke, who organized a workshop on the subject to be held during the NEES meeting in Reno. “This hybrid approach is taking off lately. People are getting very excited about it.”

Ozdagli also is presenting related findings next week during the 2013 Conference of the ASCE Engineering Mechanics Institute, to be held 4-7 August in Evanston, Illinois.

The simulations can be performed in conjunction with research using full-scale building tests.

There are very few large-scale facilities in the world, however, and the testing is time-consuming and expensive.

“The real-time hybrid simulations allow you to do many tests to prepare for the one test using a full-scale facility,” Dyke said. “The nice thing is that you can change the numerical model any way you want. You can make it a four-story structure one day and the next day it’s a 10-story structure. You can test an unlimited number of cases with a single physical setup.”

The release notes that the researchers will present two abstracts during the Reno meeting. One focuses on how the simulation method has been improved and the other describes the overall validation of real-time hybrid simulations.

To prove the reliability of the approach the researchers are comparing pure computational models, pure physical shake-table tests and then the real-time hybrid simulation. Research results from this three-way comparison are demonstrating that the hybrid simulations are accurate.

Ou has developed a mathematical approach to cancel out “noise” that makes it difficult to use testing data. She combined mathematical tools for a new “integrated control strategy” for the hybrid simulation.

“She found that by integrating several techniques in the right mix you can get better performance than in prior tests,” Dyke said.

The researchers have validated the simulations.

“It’s a viable method that can be used by other researchers for many different purposes and in many different laboratories,” Dyke said.

Much of the research is based at Purdue’s Robert L. and Terry L. Bowen Laboratory for Large-Scale Civil Engineering Research and has been funded by the NSF through NEES. A portion is supported by the Sohmen Fund, an endowment established by Purdue alumnus Anna Pao Sohmen to facilitate faculty and student exchange with the Harbin Institute of Technology and Ningbo University. The fund is managed by International Programs at Purdue.

— Read more in Ge Ou, “Application of Robust Integrated Actuator Control Strategy in Real Time Hybrid Simulation”; and Ali Ozdagli, “Comparison of shake table test with real time hybrid simulations for a large-scale” (both papers to be presented at NEES Quake Summit 2013, Reno, Nevada, 7-8 August 2013).