Structural design is... very much concerned with art, common sense, sentiment, aptitude, and enjoyment of the task of creating opportune outlines to … - Eduardo Torroja

[E]xperimental investigation of stresses in a plane structure is of great interest and merit as applied to shells with single curvature (barrel shells, pipes) and to shells with double curvature (domes, etc.). In these structures similar states of stress are produced and can be determined at any point as acting in a plane tangential to the center layer of the shell.

[C]onsider the danger of bulging and... counteract it by providing adequate anchorage, thus shortening the free length of the member and reducing its relative slenderness.

The material in all elementary parts of a structure must have the properties of resistence to all internal forces produced by general loading conditions and by the action of any exterior force.