Fast Hybrid Test Platform for Seismic Performance Evaluation of Structural Systems

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

The George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Program is a project funded under the NSF Major Research Equipment Program. This cooperative agreement, under the NEES Program, establishes a NEES fast hybrid test platform for seismic response simulation of structural components, subassemblages, and systems at the University of Colorado at Boulder, Colorado. The University of Colorado at Boulder will specify, develop, purchase/upgrade, construct, install, commission, and operate a fast hybrid test system consisting of high speed actuators, digital controller, data acquisition system, computers, and simulation software for full size and large-scale models of walls, columns, frames and subassemblies under experimental hybrid testing at loading rates between 10% and 100% of that experienced during an earthquake. This capability is one to two orders of magnitude higher than currently available in pseudodynamic tests. This equipment will be operational by 2004 or earlier and will be managed as a national shared-use NEES equipment site, with teleobservation and teleoperation capabilities, to provide new earthquake engineering research testing capabilities for large structural systems through 2014. This NEES equipment site will be connected to the NEES collaboratory through the CU Engineering Center, which already has Gigabit Ethernet connection. Shared-use access and training will be coordinated through the NEES Consortium award. This award is an outcome of the peer review of proposals submitted to program solicitation NSF 00-6, NEES: "Earthquake Engineering Research Equipment." The following equipment is provided under this award: (1) One high-speed actuator, 220 kip load capacity, +5 in stroke, 250 gpm servo valve, maximum velocity of 9 in/sec; (2) Upgrade two existing 110 kip, +5 in. stoke actuators with 250 gpm servo valves to attain a maximum velocity of 18 in/sec; (3) High-performance digital servo-controller with three control channels and three-variable control capability; (4) High-speed data acquisition system with 32 data channels; (5) Three digital displacement transducers; (6) Ten analog displacement transducers; (7) Three accelerometers with frequency range up to 500 Hz; (8) Three personal computers for numerical simulation, data processing using Matlab and C++ complier, and data display/teleobservation connection; (9) Expansion of existing data acquisition system to accommodate teleobservation, teleoperation, teletransmission, and telestorage; and (10) Equipment for teleobservation and teleoperation capabilities so that experiments on the equipment will be observable and controllable via high performance network connections. The core of the facility is the digital controller, the computer where the dynamics of the structure being evaluate is modeled and numerical computation is performed to solve the equations of motion, and the software (to be developed as part of this project) which controls and links the physical and mathematical subassemblages. Sophisticated actuator control algorithms will be developed as a part of this project and they are the keys to project success. The facility would be the only one of its kind in the United States (multiple actuators) with full substructuring capability. It would serve as the test bed for future large scale, multi-degree-of-freedom fast hybrid testing systems. The University has committed $190,685 for the control room construction and refurbishing work, equipment purchase and partial support for a laboratory technician from 2001 through 2004. The University will integrate this fast hybrid testing system into its undergraduate and graduate curricula, and it will promote the use of the results by other educational institutions mainly through the use of the World Wide Web. Further, the experimental observations obtained from the test will be incorporated in an ongoing NSF sponsored K-12 educational program. The University will also provide training opportunities for outside researchers through seminars and workshops.