2/20/2024
Faculty Profile: Billie F. Spencer
Throughout his career, this internationally recognized expert in smart structures technology has encouraged students of all ages to take a hands-on approach to engineering and innovation.
As a teenager growing up in southern Illinois, Billie F. Spencer Jr. learned to work on cars with his uncle, who owned a body shop.
“Every car I had until I graduated from college and got my first job was a salvage car,” he says. “There was one particular car – a Volkswagen Scirocco. The front end was a 1978 model with fuel injection, the rear end was a 1976 model with a carburetor, and the interior wiring and air conditioning were from a 1977 model. You could call it my Frankencar.”
This same resourceful spirit has characterized Spencer’s nearly 40-year career in academia. Today, Spencer is the Nathan M. and Anne M. Newmark Endowed Chair in Civil Engineering at The Grainger College of Engineering, University of Illinois Urbana-Champaign. He is a member of the Chinese Academy of Engineering (he is fluent in Mandarin), the Japanese Academy of Engineering, and the Polish Academy of Sciences, and a Distinguished Member of the American Society of Civil Engineers.
Among his many awards is the 2018 ASCE Newmark Medal, given “for pioneering work, innovations and leadership in the theory and application of advanced technologies to fundamental problems in structural engineering and mechanics, as well as for his unwavering commitment to education/mentoring of students and professional service.”
He is an internationally recognized expert in smart structures technology, a field in which he has invented and built such innovations as wireless sensor systems for infrastructure health monitoring, smart dampers using magnetorheological fluids for protection of civil engineering structures during earthquakes, and custom drones for structural health inspection.
“This is a signature of our work,” he says. “We’re not afraid to get our hands dirty. It’s not available? OK, let’s make it.”
Spencer grew up in Roxana, Ill., where in high school he participated on the wrestling team, called the Roxana Shells after the Shell Oil Company Refinery in town. He and his brother were raised by his father, a printer for the St. Louis Post Dispatch newspaper, and his grandmother, who worked at a garment factory. They lived in a small, two-bedroom house, so Spencer shared a room with his father and brother.
“This is a signature of our work. We're not afraid to get our hands dirty. It's not available? Ok, let's make it."
“We weren’t poor, but we weren’t rich,” he says. “We never wanted for anything, but we always did things ourselves. You repaired your own car, lawnmower, TV. It was very much a blue-collar family.”
No one in Spencer’s family had gone to college, and the guidance counselors at his high school “were primarily there to help you graduate, not to help you go to college afterwards,” he says. Nevertheless, as high school graduation approached, Spencer applied to The University of Missouri – Rolla (now the Missouri University of Science and Technology) and to the University of Illinois, and he was accepted at both. He chose Rolla partly because the wrestling program there was Division II (Illinois was Division I), so he would be able to be on the team. He qualified for Nationals, and to this day, he still holds most of the school’s wrestling records. He majored in mechanical engineering; it seemed like a good fit because of his hobby of working on cars. During his undergraduate summers, he interned at General Motors in Warren, Mich., working in their structural engineering research group in the noise and vibration laboratory.
It was during his undergraduate years that Spencer first considered research as a career. He had planned to stay a semester longer than most of his friends so he could continue to wrestle, but as graduation approached, he changed his mind. He needed a few more credits, so a professor in social sciences enrolled him in an independent study class to research the frequency of baseball batters getting hit with balls in the American League versus the National League. He had to compile statistics from issues of the Sporting News, available in the St. Louis Public Library. When he completed the project, the professor complimented his work and asked if he had ever considered getting a Ph.D.
“The answer was no,” Spencer says. “But that was the spark of it there.”
Spencer first came to the University of Illinois as a master’s student in the Department of Theoretical and Applied Mechanics (TAM), following his interest in vibration engineering. At General Motors, he had studied vibration engineering in mechanical systems, but as a graduate student he expanded his focus to include random vibration that occurred as a result of earthquake, wind and wave loading. He took courses in TAM but also in Civil Engineering and Electrical Engineering. His mentor, Illinois Professor Larry Bergman, encouraged him to pursue a Ph.D., pointing out that many of Spencer’s non-academic interests were engineering-related.
“He said my hobby could be my work, and how much better can it get than that?” Spencer says.
In addition, the teaching aspect of an academic career was appealing. As an undergraduate, Spencer had taught drafting to electrical engineers, work that he had found rewarding. During graduate school at Illinois, he also served as “a full-fledged instructor,” teaching sophomore statics, dynamics and mechanics of solids to classes of 40-100 students during five of his semesters and even winning a teaching award from the TAM department.
Because of the breadth of his coursework and experience at Illinois, Spencer found a receptive job market when he began looking for academic positions. He had interest from departments in mechanical engineering, aerospace engineering and civil engineering.
“This area of work that I did was kind of agnostic,” he says.
Spencer joined the faculty of the Department of Civil and Environmental Engineering at the University of Notre Dame in 1985. Over the next seventeen years he taught courses in mathematics, statics, dynamics, mechanics of solids, structural reliability and probability.
“After a while, I guess I morphed from being a mechanical engineer into being a civil engineer,” he says.
In 2002, Spencer returned to Illinois as a member of the CEE faculty, where he has taught graduate and undergraduate courses in structural mechanics, structural dynamics and random vibration. His work in smart structures technology has been groundbreaking. In a joint project with Illinois Computer Science Professor Gul Agha, Spencer led the development of an inexpensive, wireless means for continuous and reliable structural health monitoring. In 2009 the Illinois researchers collaborated with colleagues at KAIST in Korea and the University of Tokyo to successfully deploy the system at full scale on the Jindo Bridge in South Korea. It was the first dense deployment of a wireless sensor network on a cable-stayed bridge and the largest of its kind for civil infrastructure to date. The researchers designed, developed and tested sensors that could be manufactured very cheaply and still produce the high-fidelity data required for structural health monitoring. Their research also produced a customizable software framework that simplified the development of structural health monitoring applications for smart sensor platforms. Since then, Spencer’s group has deployed wireless smart sensors on a number of automobile and railroad bridges.
In 2015, Spencer’s group developed and deployed an even larger wireless monitoring system for the world’s biggest Ferris wheel being constructed in Dubai. The tension of the wheel’s 192 cables needed to be monitored, particularly in the construction phase. A special concern was Dubai’s intense heat. The wireless sensors were powered by lithium-ion batteries, which could catch fire if they heated up too much during the charging stage. To prevent that, Spencer’s team developed a special circuit that would shut off the charging if the temperature became too high. The system worked in sync with the climate, charging the batteries in the cooler morning and evening hours.
Another area in which Spencer has taken an innovative approach is in the use of drones for structural inspections. In a project for the U.S. Army Corps of Engineers, he led the development of a specially designed drone to perform automated inspections of the lock gates on dams. The high walls on the lock chamber result in a GPS-denied environment, so drones can’t navigate using satellite signals. With no readily available platform that allowed a drone to operate without GPS, Spencer had to invent one.
“There’s a 3D-depth camera on the front and a mini-computer on the back, so it can take in the information, process it using machine learning and then send it to a controller that will cause the drone to execute whatever mission is needed,” Spencer says.
Because ready-made drones operate with proprietary computer systems, Spencer had to buy a drone he could assemble and program himself. He bought two, built the first one to learn how to do it, and then had his students build the second. Their testbed is the cul-de-sac between Newmark Lab and the new Civil and Environmental Engineering Building, where the height of the buildings also hampers GPS signals.
Spencer’s newest project is developing what he calls a “soup to nuts” approach for structural health inspection. After an earthquake or other widespread disaster, the system will send out drones to take photos of important infrastructure using computer vision and machine learning to help assess the condition of structures. The idea is to multiply the efforts of first-responding engineers and get critical infrastructure back in use as soon as possible. He is motivated by the lesson of the 311 earthquake in Japan on March 11, 2011, when infrastructure was crippled after the earthquake and resulting tsunami damaged homes, businesses, roads and railways. In such disasters, Spencer says, there may be thousands of damaged structures and only hundreds of engineers to assess their condition.
“Our idea is that you’ve got an army of drones that are ready to be deployed and do that initial inspection to help people to return more quickly to their lives and businesses,” Spencer says.
This army of drones would collect the images and analyze the structures’ condition by comparing the photos with a graphics-based digital twin, a 3D synthetic environment that combines a numerical model of the structures with photorealistic visual imagery.
“We have a model of a structure that is of interest to us,” Spencer says. “If an earthquake occurs, we can run a simulation in the digital twin and then send the drone out to look at the relevant portions.”
When it is complete, the system will be unique in the world, Spencer says.
Despite his long and growing list of research and technological innovations, Spencer views his students as his finest accomplishment. It is a fitting perspective, given the impact that encouragement from teachers has played in his own life. He has graduated nearly 40 Ph.D. students so far. After working with Spencer, many students have gone on to pursue careers in research and education themselves, taking positions at universities in the U.S., Taiwan, Japan, China, Korea and Ecuador. He has inspired students internationally through programs he developed such as the Natural Hazard Mitigation in Japan initiative, which facilitated a summer study abroad for over 100 students. His Asia-Pacific-Europe Summer School on Smart Structures Technology has trained over 600 students since its inception in 2008, including being hosted twice at Illinois. A K-12 outreach program he developed in 1998 called “Shakes & Quakes”teaches younger students about earthquakes and engineering and includes testing structures they build with Legos or K’Nex on a tabletop shake table. Over the past 25 years, Spencer and his graduate students have visited local schools to present the program, as well hosted crowds of pupils on campus.
“I can make a cool drone; somebody else will make a better drone. I can develop some algorithms; somebody is going to do better. But the students are going to go out and make their own, lifelong impact,” Spencer says. “We’ve written some good papers, done some good research, it’s gotten good visibility, but it’s the students who really make the job worthwhile. That’s really the product of our labor. I view the research as the tool by which we educate them to be the next generation of leaders in the field.”
“It's the students who really make the job worthwhile. That's really the product of our labor. I view the research as a tool by which we educate them to be the next generation of leaders in the field."