Half a century ago, John W. Fisher began studying steel bridges and the cracks that form in them when the structures are subjected to fatigue, or repeated stresses.
In the years since, says Fisher, a professor emeritus of civil engineering, his life’s work has “unavoidably” expanded to include almost all types of bridge and infrastructure failures.
Fisher is regularly called upon to offer expert analysis when bridges or building collapse or threaten to. A short list of these projects includes the Interstate 35W Bridge in Minnesota (2007), the World Trade Center (2001), the Northridge-Los Angeles Earthquake (1994), the Mianus River Bridge on Interstate 95 in Connecticut (1983), the Hyatt-Regency walkway in Kansas City (1981), and the Hartford Civic Center Arena roof (1978).
Of his career, Fisher says, “It has been a unique collision of research work and what’s going on in the real world.”
Recently, at the 5th New York City Bridge Conference, that convergence settled into harmony when the Bridge Engineering Association created a new award to recognize the significance of Fisher’s work.
The John W. Fisher Student Award honors Fisher as one of the nation’s top experts in fatigue and fracture of steel bridges. It will be given annually to a student pursuing a degree in bridge engineering.
This year’s recipient, Feng Miao, a Ph. D. candidate at the City College of New York, is developing methods to determine the reliability of a bridge after one or more of its small components fail. She is also evaluating bridges using the Load and Resistance Factor Design method of the American Association of State Highway and Transportation Officials (AASHTO).
“I was very pleased to see an award like this in my name,” said Fisher, “and I felt honored to present it to its first recipient.”
Prolonging a bridge’s service life
Fisher’s colleague, Alan W. Pense, was also honored at the 5th New York City Bridge Conference. Pense, provost emeritus and professor emeritus of materials science and engineering, received the Bridge Engineering Association’s Bridge Engineering Research Award.
Fisher, who received his Ph.D. from Lehigh in 1964, has taken home almost every award in his field, including the 2001 Bridge Engineering Research Award for “cutting-edge research in fatigue prone details that has lengthened the service life of bridge structures.”
In 1986, he helped found the Engineering Research Center for Advanced Technology for Large Structural Systems (ATLSS), Lehigh’s world-renowned civil infrastructure research center. Over the years, he has maintained a strong presence at the facility, studying wear on steel and iron bridges caused by cyclic loads of traffic. His research helps to identify precisely how trucks passing over the same spot again and again can cause cracks to develop and how proper engineering can counter those forces.
“Very few undergraduates spend time exploring the effect of cyclical loading,” says Fisher. “This is a crucial concept for engineers to understand, whether they’re bridge engineers or other engineers responsible for the resiliency of any structure or equipment under these conditions. Any civil engineering project could experience a problem caused by the same issues that cause bridges to collapse.”
Story by Elaine Hardenstine
Posted on Friday, October 30, 2009