The ATLSS Research Center has opened a state-of-the-art new testing facility that simulates the effects of earthquakes and promises to help engineers build structures that better withstand seismic events and explosions.
The unveiling of the real-time, multi-directional (RTMD) testing facility on Nov. 15 attracted top university officials to the ATLSS (Advanced Technology for Large Structural Systems) Center.
Visitors saw a demonstration of a 20-foot-long, torpedo-shaped actuator, which can impose 500,000 pounds of force on structures from a variety of angles at the rate of 1 meter per second.
They also saw displays of advanced instruments, including paint that senses the formation of bridge cracks, optical fibers that detect earth tremors (and water buildup in landfills), and wireless accelerometers that measure the speed and orientation of movement in earthquakes.
The event was part of a nationwide "open house" of the National Science Foundation's George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES). Formed in 2003, NEES consists of 15 universities, including Lehigh, that conduct research on earthquakes and tsunamis and their effect on soil, buildings, bridges, pipelines and other structures.
The Lehigh portion of the NEES open house was attended by Lehigh's new provost, Mohamed El-Aasser, who is the former dean of the P.C. Rossin College of Engineering and Applied Science; David Williams, vice provost for research; Arup SenGupta, chair of the civil and environmental engineering department; and Richard Sause, director of ATLSS.
"The RTMD facility is an outstanding addition to Lehigh's research infrastructure," said El-Aasser. "This facility represents our ongoing commitment to structures and advanced materials as one of Lehigh's leading research thrusts."
Bill Michalerya, associate vice president for government relations, said NEES would help Lehigh continue serving as an "economic engine for the Lehigh Valley and Pennsylvania."
The new NEES funding from NSF, combined with financial support ATLSS receives from the Pennsylvania Infrastructure Technology Alliance, will boost efforts by Lehigh and the City of Bethlehem to make the Lehigh Valley more hospitable to graduating college students seeking jobs, said Michalerya.
The members of NEES are linked by Internet2, which enables universities to share data from experiments and allows off-site researchers to interact in real time with any of the networked sites.
Jim Ricles, professor of civil and environmental engineering and principal investigator on the RTMD project at Lehigh, said the project has a twofold mission.
"We want to verify new advanced experimental methods and develop new ways to simulate earthquakes. If we're successful, we can save money and lives and minimize damage caused to structures by earthquakes."
In one experiment, said Ricles, Lehigh's NEES researchers are working with counterparts at the University of Illinois and Rensselaer Polytechnic Institute to simulate the effect of earthquakes on a freeway ramp, several freeway bridge columns and the soil foundation. The columns - a half-scale replica of one is being tested at ATLSS - were damaged during the 1994 Los Angeles earthquake.
The experiment with Illinois and RPI, called a distributed hybrid test, is being done simultaneously (coherently and concurrently) at the three sites to gain an integrated idea of what happened systemically to the freeway ramp, soil foundation and bridge columns during the quake. Data from all three physical experiments will be integrated with an analytical test being done at the National Center for Supercomputer Applications.
Until now, said Ricles, earthquake engineering experiments have focused on single structural members as opposed to entire systems.
"Before, one isolated specimen was tested without integrating the data to the overall bridge structure. But if you test only one member, you don't know how the rest of the structure will react.
"After we prove the worth and accuracy of distributed hybrid testing, we can use it to demonstrate alternative types of constructions and renovations. It will be a tool to demonstrate as realistically and accurately as possible the real-time performance of a structure during an earthquake."
The RTMD facility represents an investment of almost $4 million, said Ricles, with over $3 million coming from NSF and the rest from Lehigh and PITA.
The 20-foot-long actuator - Lehigh has five - is the largest of its kind, said Ricles, and it gives ATLSS 30 times more hydraulic power than it had before. An advanced high-speed data acquisition, coupled with advanced sensors and an eight-channel digital control system, enables the RTMD facility to be seen or operated remotely from computers with Internet access.
Sibel Pamukcu, associate professor of civil and environmental engineering and co-principal investigator on the NEES project, said the Lehigh NEES researchers have initiated outreach efforts to local K-12 schools and collaborations with universities in England and Japan.
Posted on Wednesday, December 01, 2004