Glossary (глосарій)

It can be stated as follows: If a set of self-equilibrating loads are applied on a body over an area of characteristic dimension d, the internal stresses resulting from these loads are only significant over a portion of the body of approximate characteristic dimension d. Note that this principle is rather vague, as it deals with 'approximate' characteristic dimensions. It allows qualitative rather that quantitative conclusions to be drawn. An important application of Saint-Venant's principle deal with end effects in bars and beams.

are properties specific to the geometry (dimensions) of the setion used. These are different from material properties which depend on what an object is made of.

is  а force acting along the plane which passed through а body,

Shear modulus is the ratio of shear stress divided by the shear strain in the elastic region. It can also be referred to as modulus of rigidity or torsion modulus.

has the same units as normal stress (force / area) but represents a stress that acts parallel to the surface (cross section).

is the algebraic sum of all the vertical forces to one side of any cross section of the beam  

is freely supported at both ends one

is the property of the structure to keep its initial position of equilibrium

 the case when there are three equations of static equilibrium available for the system and these are sufficient to determine the three unknowns

is the ability of the structure to resist the strains caused by the external forces acting upon it