Principles and definitions

The basics of beam theory were the subject of a previous article [ Form. B 5 020 ] in which, in addition to definitions and terminology, the fundamental assumptions were formulated.

Expressions for stresses and strains due to normal force, bending moment, shear force and torsional moment have also been provided.

These contributions show that knowledge of the system of external forces relative to the cross-section (or cross-section "stresses") is sufficient to determine stresses and strains, and thus to justify the strength and serviceability of the parts in question.

We also retain the properties of...