Hardy Cross

Hardy Cross ( born February 10, 1885 in Nansemond County, Virginia, † February 11, 1959 in Virginia Beach ) was an American civil engineer.

Cross studied at Hampden Sydney College, where he earned degrees as a teacher of English and mathematics, which he held until 1906 taught at the Norfolk Academy 1903. He then studied civil engineering at the Massachusetts Institute of Technology with a bachelor's degree 1908. He worked for the bridge department of the Missouri Pacific Railroad in St. Louis. In 1911 he received a master's degree from Harvard University. As a teacher, he taught for seven years as Assistant Professor at Brown University. After a short practical activity, he became in 1921 a professor of structural engineering at the University of Illinois at Urbana- Champaign. From 1937 he was a professor at Yale University and director of civil engineering faculty. In 1951 he retired.

The cross- method (Analysis of continuous frames by distributing fixed -end moments, Proceedings ASCE 1930), an iterative method for determining the bending moments at the end of the rods of rod structures and trusses, is named after him. It was well suited for highly statically indeterminate systems and quickly found widespread use for example in high-rise construction. Cross also provided contributions that led to the finite element method later. In 1958 he received the Gold Medal of the Institution of Structural Engineers.