Clifford A. Truesdell III, a retired Johns Hopkins professor who earned international acclaim for his work in the field of rational mechanics, died Jan. 14 of heart failure. Truesdell, who also was recognized as an expert in European art and culture, was 80 and a resident of Baltimore.

"He brought a tremendous mathematical rigor and sense of historical perspective to a field that forms the basis of mechanical engineering today," Andrew Douglas, associate dean for academic affairs and former chairman of the Mechanical Engineering Department, told The Sun. "He is one of the few people who made a lifelong study of rational mechanics--how materials behave. He also was a pioneer in thermodynamics. His most significant contribution was to go back and put rational mechanics in a rigorous mathematic framework. His writings forced people to do things right and rationally."

Truesdell joined Hopkins as a professor of rational mechanics in 1961 and remained one of its most prominent engineering scholars until his retirement in 1989. He wrote or co-wrote 26 books and more than 200 papers and edited journals for the field of rational mechanics. He was a member of the American Academy of Arts and Sciences and received numerous professional awards, including the Humboldt Prize.

A native of Los Angeles, Truesdell earned degrees from the California Institute of Technology, Brown University and Princeton.

Funeral services were private.