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Damper sold for home use
California residence to get seismic device tested by UB, RPI
By ELLEN GOLDBAUM
Contributing Editor
Just weeks after UB and Rensselaer Polytechnic Institute successfully conducted the first tests of seismic dampers for residential applications, the firm that manufactures the dampers, Taylor Devices, has made its first sale of the protective devices for a residence.
Michael Symans (left) and Andre
Filiatrault show off a seismic damper that will be installed in a luxury
residence being built in southern California. The damper, which is installed in perimeter walls
of a structure, takes the energy of an earthquake and converts it to
heat, removing it from the structure.
PHOTO: NANCY J. PARISI
By the end of the year, a dozen of the devices, manufactured in North Tonawanda, will be installed in a major, $35-million luxury residence in southern California.
Completed in early July, the damper tests were part of NEESWood, a four-year, $1.24 million National Science Foundation-funded consortium project. NEESWood researchers are using data from the tests to further improve performance for wood-frame construction. The goal of NEESWood is to develop a better understanding of how wooden structures react to earthquakes so that larger and taller structures can be built safely in seismic regions worldwide.
One of the objectives of the final test of the wood-frame townhouse on UB's twin shake tables is to investigate the behavior of anchored and unanchored content inside the building, including furniture items and objects. Researchers are seeking donations of items to "furnish" the townhouse, including floor lamps, old furniture and home furnishings, books, dishes, picture frames and wall hangings. Anyone with donations should contact Thomas M. Albrechcinski, site operations manager for the Structural Engineering and Earthquake Simulation Laboratory, at tma1@buffalo.edu, or 645-2114, ext. 2420. Donated items will not be returned.
Because of its sheer size—the master bedroom alone is 3,000 square feet—the frame of the luxury home where the dampers will be installed is being built of steel, not wood. But, according to Douglas P. Taylor, chief executive officer of Taylor Devices and a UB alumnus, the lessons learned during the tests are applicable.
"NEESWood is demonstrating that what works to mitigate seismic damage in other projects can also work for residences," he said.
Taylor Devices' seismic dampers have been installed in more than 200 commercial buildings and bridges worldwide; this sale marks the company's entry into the residential market.
"Our work with UB and RPI on NEESWood has introduced us to a new market sector," Taylor added. "It's making the public aware that this technology can be used in residences as well."
"It's very exciting and rewarding to see the research results generated in the NEESWood project being implemented so quickly," said Andre Filiatrault, professor of civil, structural and environmental engineering and the leader of the NEESWood experiments at UB.
At an estimated cost of $50,000 including installation, the $35-million California project will utilize a dozen seismic dampers, which are designed to be installed within a home's perimeter wall. After the walls are sheathed in plywood and gypsum, the dampers are invisible.
Each silicon-fluid-filled damper, measuring approximately 20 inches long and 3.5 inches in diameter, can dissipate about 10,000 pounds of force. The dampers take the energy of the earthquake and convert it into heat, removing it from the structure. The heat then dissipates into the atmosphere.
In early July, under the supervision of Michael Symans, associate professor of civil and environmental engineering at RPI, a 73,000-lb., 1,800-square-foot townhouse equipped with four seismic dampers was subjected to a simulation of a magnitude 6.7 earthquake on UB's twin shake tables.
Those tests confirmed that the dampers were able to dissipate a portion of the energy from the simulated earthquake ground motions, thus reducing the energy that needed to be dissipated by the wood framing system.
"The reduced energy-dissipation demand on the wood framing system indicates that the damage in wood buildings subjected to earthquakes could be reduced significantly by incorporating dampers," said Symans. "The full-scale tests at UB were very helpful in understanding how the dampers likely would perform in a field application. It is very gratifying to see that the testing at UB, along with prior prototype testing at RPI, has led to an application of dampers in a residential structure."
"We are very fortunate to have industry partners like Taylor Devices participating within the NEESWood project," said John W. van de Lindt, NEESWood project director and associate professor at Colorado State University. "Many engineering fields, including earthquake engineering, now are being evaluated based on the impact of new discoveries to industry and society as a whole."
The UB testing will conclude in November when the furnished, three-bedroom, two-bathroom townhouse will be subjected to the most violent shaking possible in a laboratory—mimicking what an earthquake that occurs only once every 2,500 years would generate.
The tests are the first step in moving toward performance-based design for wood-frame structures. NEESWood will culminate with the validation of new design processes using a six-story, wood-frame structure that will be tested on the world's largest shake table in Miki City, Japan, early in 2009.
NEESWood is a collaborative research project led by van de Lindt at Colorado State University. Co-principal investigators are Rachel Davidson, assistant professor of civil and environmental engineering at Cornell University; Filiatrault of UB; David V. Rosowsky, professor and head of the department of civil engineering at Texas A&M University; and Symans at RPI.