Hardy Cross
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Hardy Cross, 1885-1959, born in Nansemond County, Virginia, was a U.S. engineer and the developer of the moment distribution method.
He obtained a BS in civil engineering from the Massachusetts Institute of Technology in 1908, and then joined the bridge department of the Missouri Pacific Railroad in St. Louis, where he remained for a year, after which he returned to Norfolk Academy in 1909. After a year of graduate study at Harvard he was awarded the MCE degree in 1911. Hardy Cross developed the :moment distribution method wile working at Harvard university. He next became an assistant professor of civil engineering at Brown University, where he taught for seven years. After a brief return to general engineering practice, he accepted a position as professor of structural engineering at the University of Illinois, Champaign-Urbana, in 1921. At the University of Illinois Hardy Cross developed his moment distribution method and influenced many young civil engineers. His students at Illinois had a hard time arguing with him due to the fact that he was hard of hearing.
He was the developer of the "moment distribution method" and one of the USA's most brilliant engineers. Brilliance often times takes some creativity, which can be seen in Cross's honorary Master of Arts from Yale. Accurate structural analysis of large reinforced concrete building frames in the 1950s was a formidable task. It is a tribute to the engineering profession, and to Hardy Cross, that there were so few failures. When engineers had to compute the stresses and deflections in a statically indeterminate frame, they inevitably turned to what was generally known as the "moment distribution" or "Hardy Cross" method. In the moment distribution method, the fixed-end moments in the framing members are gradually distributed to adjacent members in a number of steps such that the system eventually reaches its natural equilibrium configuration. however the method was still an approximation but it could be solved to be very close to the actual solution.
Today the "moment distribution" method is not commonly used due to the fact that computers have changed the way that engineer's evaluate structures.
Moment Distribution programs (http://www.freesoftware.com.my) are seldom created nowadays. Today's structural analysis software are based on the flexibility method, matrix stiffness method or finite element methods (FEM).
Although the Cross method has been superseded by more powerful procedures such as FEM, the "moment distribution method" made possible the efficient and safe design of many reinforced concrete buildings during an entire generation.
Another Hardy Cross method is also famous for modeling flows in complex pipe networks. Until recent decades, it was the most common method for solving such problems.
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