Origin of equilibrium methods applied to the structural calculation of long cylindrical shells

Abstract

Trabajo de investigación sobre el origen de la aplicación del método plástico para el cálculo estructural de las cáscaras cilíndricas largas de cubierta de hormigón armado, obteniendo un método basado en las ecuaciones de equilibrio de la estructura, sencillo y seguro.

Assessing the state of stress of a cylindrical shell, according to elastic theory, originally consisted of formulating hypotheses about the conditions surrounding it, which were impossible to determine beforehand, and the type of structural material used, which had to be ideal, uniform and isotropic. However, even when it was possible to solve complex second-degree equations, there was no guarantee that this state of stress represented the ‘real’ state of the shell. Plastic theory emerged as a consequence of the shortcomings of elastic theory. It was also the twentieth century’s most important contribution to structural theory. This study looks at a specific episode, which has barely been studied and is part of the history of plastic or breaking load calculations, and concerns the origin and subsequent application of the plastic method as an ideal tool for the structural calculation of long cylindrical shells. It meant that they could be calculated easily and accurately, as will be discussed below.