Professor Emeritus John Rudnicki Passes Away

John Rudnicki, professor emeritus of civil and environmental engineering and mechanical engineering, passed away October 4, 2026, at age 75. Rudnicki will be remembered for transforming the understanding of how deformation, diffusion, and shear heating interact during earthquakes, and for mentoring future generations of engineers. 

"John Rudnicki leaves an extraordinary legacy in geomechanics and geophysics. His fundamental contributions transformed our understanding of deformation, failure, and strain localization in geomaterials,” said Gianluca Cusatis, a professor of civil and environmental engineering at Northwestern Engineering. “An inspiring and deeply committed educator, John brought rigor and enthusiasm to the classroom, leaving a lasting impact on generations of students who benefited from his exceptional teaching and mentorship. We will remember John not only for his remarkable scientific achievements but also for his noble and friendly character and his dedication to advancing knowledge. He will be deeply missed."

Rudnicki joined the McCormick School of Engineering in 1981 as an associate professor of civil engineering and of theoretical and applied mechanics, and was promoted to professor in both areas in 1990. In 1991, he was also named a professor of mechanical engineering. This spring, Rudnicki transitioned to emeritus status and was honored with the symposium, “A Celebration of John Rudnicki’s Contributions to Geophysics and Geomechanics.”

“John was an exceptional mentor, a distinguished educator, and a giant in the field of mechanics. During his 45 years at Northwestern, he made significant contributions across a wide range of areas, including geomechanics, plasticity, granular matter, and biomaterials,” said Sinan Keten, Jan and Marcia Achenbach Professor and chair of mechanical engineering at the McCormick School of Engineering. “John was a dear colleague and friend to many in our community. His wisdom, candor, and genuine care for colleagues and students were deeply appreciated. His passing is a profound loss to our community, and he will be greatly missed.”

Before coming to Northwestern, Rudnicki worked as a research fellow and instructor in geophysics at the California Institute of Technology from 1977 to 1978, and then as an assistant professor of theoretical and applied mechanics at the University of Illinois Urbana-Champaign from 1978 to 1981. Rudnicki earned a bachelor of science in engineering mechanics in 1973, a master of science in solid mechanics in 1974, and a PhD in solid mechanics in 1977, all from Brown University.

Rudnicki studied how rocks and other geological materials deform, fracture, and fail, and how those processes are influenced by fluids. His work helped advance understanding of fault instability, the energy released by earthquakes, and problems in environmental and resource-related geomechanics. His research interests also extended to the mechanics of rat whiskers.

Rudnicki received numerous honors for his contributions to engineering mechanics, rock mechanics, and geomechanics. He was elected a fellow of the American Rock Mechanics Association, the Engineering Mechanics Institute of the American Society of Civil Engineers, and the American Society of Mechanical Engineers. His awards included the Society of Engineering Science’s Engineering Science Medal, ASME’s Daniel C. Drucker Medal, Brown University’s Engineering Alumni Medal, and the Maurice A. Biot Medal, which recognized his fundamental contributions to the mechanics of porous media and its applications to rock mechanics and geophysics.

“We were privileged to have John as a member of our department. Beyond his extraordinary scholarly accomplishments, I will remember John most for his humor, kindness, and integrity,” said Yu (Marco) Nie, Roxelyn and Richard Pepper Family Chair in Civil and Environmental Engineering. “He was a wonderful colleague whom I feel fortunate to have known.”

An author of more than 100 academic papers, Rudnicki published Fundamentals of Continuum Mechanics (Wiley, 2014). The book introduces the fundamentals of the subject while providing a foundation for developing numerical methods to model large deformations and a wide range of material behaviors. A thought leader in his field, Rudnicki held several distinguished positions during his career, including serving on the US Department of Energy’s Geosciences Council from 1997 to 2010 and as its chair from 2008 to 2010.

Rudnicki was also a dedicated educator and mentor, teaching mechanics courses at both the undergraduate and graduate levels. His undergraduate teaching included Engineering Analysis II (GEN_ENG 205-2), Mechanics of Materials (CIV_ENV 216-0), and Mechanics of Sports (MECH_ENG 360). At the graduate level, he regularly taught Mechanics of Continua I (CIV_ENV 417), along with Mechanics of Continua II (CIV_ENV 417-2), and Inelastic Constitutive Relations for Solids (MECH_ENG 466).

“John has always been a gentleman, caring, and principled colleague who was passionate about helping students, either as professor or as their adviser,” said Manohar Kulkarni, clinical full professor and assistant chairperson of mechanical engineering at the McCormick School of Engineering. “I will miss him.”

Visitation will be 4-8 p.m., on Friday, Oct. 16 at Donnellan Family Funeral Services (10045 Skokie Blvd., Skokie, IL 60077).