From Bethlehem to Kyoto

Thomas Matarazzo, '15 Ph.D., discusses how his five years studying structural health monitoring at Lehigh has prepared him for an NSF-funded post-doctoral role at Kyoto University

Thomas Matarazzo and Shamim Pakzad
Thomas Matarazzo (left) stands alongside his advisor Shamim Pakzad, associate professor of structural engineering, at the former's hooding ceremony earlier this year.

Stanford or Lehigh?

It was a question Thomas Matarazzo spent months mulling over in the spring and summer of 2010, but it's one he jokes about today with his former professors, now colleagues in civil engineering research.

Matarazzo completed his Ph.D. in structural engineering at the latter school earlier this year, a culmination of nearly five years of intensive work that has set him on a path to Kyoto University as an NSF-funded post-doctoral researcher in the world famous Disaster Prevention Research Institute. But he still remembers those anxiously exciting few months when he was making that important decision.

Matarazzo had just completed his B.S. in civil engineering from Manhattan College, and he knew graduate school was next. "I didn't have a specific, detailed plan," he said, "but I thought grad school was something I'd be good at, and I figured that once I got started, it wouldn't take long to figure out what might come next."

It actually happened before he even arrived for his first semester in Bethlehem. A summer meeting with Shamim Pakzad, associate professor of structural engineering and Matarazzo's eventual Ph.D. advisor, presented Matarazzo with an opportunity to join a research team looking into a new way to conduct structural health monitoring. "It's doing system identification, which is the process of identifying natural frequencies and other vibration properties in existing structures using sensor data," he said. "This has been going on for a while, but Dr. Pakzad's idea was to do it with sensors that are moving over a bridge."

As Matarazzo explains, a structure's vibrations are like a fingerprint unique to each one and recording the way these vibrations dissipate or resonate in the system is vitally important to determining whether the structure is ready to withstand forces like wind and seismic activity. The idea to use mobile, rather than static, sensors to capture this data enables engineers to capture more data from more positions. It's also less expensive and easier to implement.

But at the time of his meeting with Pakzad, the analytical and mathematical methods to make this idea executable were totally unknown to Matarazzo. However, he looked forward to the challenge and appreciated Pakzad's clear vision. "Looking back at everything I've done, I'm obviously really happy about the decision to come to Lehigh. The department's graduate program is truly excellent."

Matarazzo is now taking what he learned and discovered about structural health monitoring and applying it to new projects in Kyoto, an opportunity he started to pursue back in February with an NSF proposal through their East Asia Pacific Summer Institute (EAPSI).

"About 200 students were selected from my class to go to nations like China, Japan, South Korea, Thailand, Australia, and more," Matarazzo said. "They're from all the different sciences. I know someone in Kyoto who was studying trees, and another person on a small southern island in Japan observing the social patterns of monkeys. Actually, fewer than half of those participating this year are engineers, and only a handful are civil engineers."

His proposal: Go to Kyoto University and use one of its large vibrating steel frames to collect data and simulate a sensor network failure. It's a slight departure from the crux of his thesis, but it's something he discovered during his time at Lehigh that he feels there's a real need for in the structural engineering community.

"Let's say there's an earthquake, and you've collected the vibrations, but the sensors weren't perfect," Matarazzo posits. "The data is extremely important to tell you whether the structure is damaged or not, but it's also incomplete. What do you do?"

This practical application of system identification with missing data covered most of Matarazzo's summer at Kyoto. There, he worked with other post-doctoral researchers and students from all over the world China, Greece, Italy, Japan.

After a few weeks of transition time, he's heading back to Kyoto for a longer-term assignment as a post-doc, where he'll supervise and participate in several research projects that are still being developed.

Masayoshi Nakashima is both a fellow Lehigh graduate, '81 Ph.D., and the director of the DPRI. Matarazzo says he expects to work closely with Nakashima analyzing data from the world's largest shake table, which is located only miles away from Kyoto University.

Additionally, Matarazzo plans to further explore the area of structural health monitoring by applying different combinations of sensors to experimental structures to find out how to maximize both efficiently and precision in sensor networks.

By John Gilpatrick



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