Analysis of Girders: Beams, Plate Girders, and Continuous Girders

Abstract

Beams and girders, made of cast iron, plate iron, lattice work, or sawn wood, were in widespread use in the nineteenth century for the support of floors, roofs, and bridge structures. This chapter discusses some of the widely used empirical methods and the methods based on bending theory, either through the development of semiempirical rules of thumb or through direct analysis. By the end of the nineteenth century, design of girders was primarily analytical. The application of continuous girders depended on the production of girders that were long enough for multiple spans and on the development of analytical procedures that were equal to the task of calculating bending moments in these girders. Whereas the application of analytical methods was necessary to the development of continuous girders, simply supported girders could be designed by empirical or semiempirical methods.