An iterative approach used before the age of computers.
The Theory of Structure is the branch of engineering mechanics that deals with the behavior of structures under load. It predicts how beams, trusses, frames, arches, and cables will react to forces such as tension, compression, bending, and torsion. The primary goals are: theory of structure -66454- pdf
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The often includes deflection tables for standard load cases. An iterative approach used before the age of computers