(Press-News.org) Writer: Emil Venere, (765) 494-4709, venere@purdue.edu
Sources: Shirley Dyke, 765-494-7434, sdyke@purdue.edu
Related Web sites:
NEES: http://www.nees.org
PHOTO CAPTION:
Earthquake-engineering researches at the Harbin Institute of Technology in China work to set up a structure on a shake table for experiments to study the effects of earthquakes. Purdue University civil engineering students are working with counterparts at the institute to study the reliability of models for testing a type of powerful damping system that might be installed in buildings and bridges to reduce structural damage and injuries during earthquakes. (Photo courtesy of Harbin Institute of Technology)
A publication-quality image is available at https://news.uns.purdue.edu/images/2013/dyke-dampers.jpg
ABSTRACT
Application of Robust Integrated Actuator Control Strategy in Real Time Hybrid Simulation
Presenter: Ge(Gaby)Ou, Purdue University
Corresponding Author: Ge Ou (gou@purdue.edu)
Real-Time Hybrid Simulation performs substructure test in real-time scale and includes rate dependent feature in consideration. One major challenge for RTHS is that it requires accurate and prompt execution of boundary condition that is calculated from numerical substructure. In most cases, traditional PID control induces large time lag between desired command and response which may cause system instability and further the failure of the test. Many control strategies for servo hydraulic actuator-structure system have been proposed recently to compensate such time lag and other system dynamics. This presentation introduces a new integrated control strategy into RTHS. The new proposed algorithm integrates three key control components; first, a loop shaping feedback control based on H-∞ optimization, second the Kalman filter for feedback estimation and a pure delay feed-forward block for control performance enhancement. The combination of the aforementioned blocks provides flexible performance according to different control evaluation criterion. RIAC has been applied for displacement tracking through RTHS of a 3DOF steel structure with equipped magnetorheological (MR) damper located in Harbin, China. The experimental components herein is the MR damper attached to a large scale actuator has maximum force capacity of 2000N, the numerical substructure is the rest of the steel structure.
ABSTRACT TWO
Comparison of shake table test with real time hybrid simulations for a large-scale
Presenter: Ali Ozdagli, School of Civil Engineering, Purdue University
Corresponding Author: Ali Ozdagli (aozdagli@purdue.edu
Real-time Hybrid Simulation (RTHS) enables physical testing of critical sub-structural elements in a cost-effective way, compared to other existing test methods such as shake table or pseudo-dynamic testing. As RTHS methodologies develop, there is still a pressing need to assure growing interest from civil engineering community seeking for validation. To meet community expectations and reveal the feasibility of RTHS, an international multi-university research project has been proposed focusing on verification of RTHS with shake table tests. The development and implementation of the comparison tests comprise the following tasks: (1) a 3.6 meters tall three story 3-D steel frame structure with base plan dimension of 1.84 m by 2.04 m -- located in Structural and Seismic Test Center at Harbin Institute of Technology, China -- was selected to be tested on the shake table; (2) a 2500 N capacity magneto-rheological (MR) fluid damper was attached to the first floor of the frame as the main energy dissipation device; (3) the integrated system was tested on the shake table under various earthquake inputs, and analytical simulations were developed for the comparison basis; (4) for the RTHS scheme, the system was divided into physical and numerical components. The steel structure was modeled as the numerical substructure whereas the MR damper was chosen as the physical component as it allows test repeatability without compromising system integrity. A 2500 kN capacity actuator is used as the transfer interface between physical and numerical substructure. Accuracy of numerical models, performance of MR damper controllers and data quality of RTHS are evaluated through comparisons with shake table structural responses. The results indicate that RTHS concept can be considered as a reliable and efficient testing method.
Simulations aiding study of earthquake dampers for structures
2013-07-31
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