birthday bio: hardy cross

Birthday Bio: Hardy Cross


Hardy Cross was an American civil engineer and mathematician born February 10, 1885. He is best known for his work in the development of the moment distribution method, a structural analysis method for indeterminate structures that is widely used in the design of reinforced concrete buildings. He later went on to apply this geometric solution method to pipe flow distribution called the Hardy Cross method. He was awarded the National Medal of Science in 1966 for his contributions to the field of engineering.


1. Moment Distribution Method

Accurate structural analysis of statically indeterminate beams and frames could be performed by hand using the moment distribution method. In this 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.


2. Hardy Cross Method

In November 1936, Cross applied the same geometric method from moment distribution paper to solving pipe network flow distribution problems, and published a paper called "Analysis of flow in networks of conduits or conductors." The Hardy Cross method is an application of continuity of flow and continuity of potential to iteratively solve for flows in a pipe network. The introduction of the Hardy Cross method for pipe flow analysis transformed municipal hydraulic engineering and design. 


Happy Birthday!

Today the hand calculations for the moment distribution method and the Hardy Cross method have been replaced by computer calculation. Computer software has changed the way engineers evaluate structures. However, that doesn't mean we still don't owe a huge thank you to the leaders, such as Hardy Cross, for paving the way. The moment distribution method and the Hardy Cross method are still widely taught amongst many of the Civil Engineering programs across the country.

Today's structural analysis software is based on the flexibility method, direct stiffness method or finite element methods (FEM). At RISA,  we focus on direct stiffness method or finite element methods(FEM). So, if you are in the market for an integrated structural engineering suite that provides best-in-class technical support, reach out today! 

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