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Lehigh University logo
Lehigh University logo

Pioneer in fracture mechanics honored

Richard Hertzberg ’65 Ph.D. retired two decades ago as the New Jersey Zinc Distinguished Professor in Lehigh’s department of materials science and engineering. An expert in fracture mechanics, he spent his career studying the cracks that form and spread in airplanes, bridges, ships and other structures.

This spring, Hertzberg received the 2017 Paris Gold Medal from the International Congress on Fracture (ICF) for his contributions to the field of fatigue fracture. The award, given every four years, is named for the late Paul C. Paris, who was Hertzberg’s Ph.D. dissertation adviser at Lehigh. Paris developed the Paris Law of Crack Propagation—a model of fatigue crack growth now used worldwide.

Richard P. Vinci, professor of materials science and engineering, says Hertzberg’s work with fatigue—the structural failure brought on by repeated cycles of stress—underlies many of the safety standards adopted by the aircraft and automobile industries.

“Dick worked with Paul Paris and others in the 1960s and 1970s to establish the theoretical and mathematical foundation for fracture mechanics,” says Vinci, who directs Lehigh’s Center for Advanced Materials and Nanotechnology. “He contributed to the rapid adoption of this approach in the aircraft industry through a series of important short courses that he delivered to industry and military personnel.”

Hertzberg also gained renown for his textbook, Deformation and Fracture Mechanics of Engineering Materials, first published in 1976 and now in its fifth edition, which has been translated into several languages.

Hertzberg, who earned his Ph.D. from Lehigh in 1965, has received Lehigh’s Libsch Award for Outstanding Research, the College of Engineering Teaching Excellence Award and the Hillman Faculty Award for advancing the interests of the university. The department of materials science and engineering named him its distinguished alumnus in 2015.

Since retiring, he has lectured to a variety of lay audiences, from adult education classes to elementary and high school students.

Why did the Liberty Bell crack? Hertzberg will ask a class of teenagers or ten-year-olds. Why did the Titanic sink so quickly after its fatal brush with an iceberg? By examining an extremely small surface in a bridge connection or airplane wing—often with an electron microscope—it is possible to determine how a crack formed and how it propagated and caused an entire structure to fail.

“The details on a fracture surface,” he says, “are like the fingerprints of a murder suspect on a glass of water.”