Glossary (глосарій)

 is the agreement between the test result and the "actual" value.

is the case of equilibrium when the elastic body does not try to return to its original state after removing the additional (disturbing) forces that brought it from the initial equilibrium

are the systems which have curvilinear or polygonal line image  

is a bar subject to forces or couples that lie in а plane containing the longitudinal axis of the bar

the displacement of an elastic body under the point of application of any force, in the direction of that force, is given by the partial derivative of the total internal strain energy with respect to that force

is the point at which the area might be considered to be concentrated аnd still leaves unchanged the first moment of the area about any axis

is a long slender bar subject to axial compression

is the case of stresses state, when in an arbitrary cross-section internal force factors are given to the normal force and to one or two bending moments are in the perpendicular planes

is case of stresses state at which in arbitrary cross-section the internal forces are leaded to the twisting and bending moments

is case of stresses state, when in each cross-section internal force factors are given two bending moments in the perpendicular planes

is the central part of the cross-section, in which or at its limit, the application of compressive force, causes only compressive stresses at all points of the cross-section

 is measured from the original neutral surface to the neutral surface of the deformed beam

 is a measure of how much an object deforms from its original dimensions or size in a given direction. Depending on which deformation you measure, you can calculate different types of strain.

is the property of the structure to save its strength, stiffness and stability during the exploitation time

 is the ability of a body to resist a distorting influence and to return to its original size and shape, when that influence or force is removed.

is the ratio of the breaking strength of the material to the load imposed upon it, under usual conditions.

 is given bу the product of the area of the element and the perpendicular distance between the element and the axis

When the applied force is proportional to the deflection, a material is said to obey Hooke's law. There is a linear relationship between the force and displacement and thus, linear elastic materials obey this law.

is the case, when the material is uniformly distributed in a whole body volume

is the case, when all points of the body have the same material properties

is the case, when the material properties are the same in each direction of a body

 is corresponds the case when the beam is loading by only the given external loading

when a material exhibits different mechanical properties in different directions.

is the ratio of the unit stress to the unit strain 

it The ratio of the shear stress  to the shear strain 

 is given by the summation of the moments of inertia about that same axis of аll of the elements of area contained in the finite area

is a condition that occurs during deformation of a specimen in response to an applied load in which localized deformation occurs within the gauge of the specimen, forming a region with reduced dimensions compared to the original gauge dimensions.

is case of stresses state in which in any cross-section internal force factors are given to the normal force and to one or two bending moments in the perpendicular planes

is the increase in length after fracture divided bу the initial length and multiplied bу 100 is the percentage elongation.

is a solid material composed of polymer molecules that has some structural rigidity under applied load; typically used in many general purpose applications (e.g., milk jugs, trash bags, disposable utensils, bike helmets).

is defined as the ratio of the strain in the lateral direction to that in the axial direction of bar 

is an organic compound of high molecular weight with a molecular structure composed of small repeating units (e.g., polyethylene is composed of repeat units of C2H4); polymer molecules are sometimes referred to as polymer “chains”, due to their predominantly linear physical dimensions.

are the axes, where we have the maximum and minimum values of moment of inertia for a given cross - section

are the moments of inertia, one of them has maximum and another of them has  minimum values for a given cross - section

 is given by the summation of the products of inertia about those same axes of all elements of area contained within the finite area

 is the intrinsic materials property that describes the ability of a material to resist, or oppose, the transport of electrical charge in response to an external electric field.

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

is region in a stress-strain curve of a material where the value of stress is continuously
increasing with strain, which effectively corresponds to a stiffening of the material during deformation; opposite of strain softening behavior.

is the ability of the structure to resist the influence of the external forces acting upon it

 is defined as force per unit are

is a plot of the stress on the ordinate (y-axis) versus the strain on the abscissa (x-axis).

Tensile Strength is the maximum tensile stress a material can withstand before failure.

there are  cylindrical spherical conical or toroidal shells subject to internal or external pressure from а gas or а liquid.

of beam is corresponding to the case, when a beam is loaded with only unity effort

is the ordinate of the point  Y   at which there is an increase in strain with no increase in stress