bending strain (майысу деформациясы)

Bending deformation - form deformation which interferes the straightness main body axis. Bending strain experienced by all of the body suspended on one or more supports. Each material is able to perceive a certain level of loading solids in most cases are capable of withstanding not only the weight, but also a predetermined load. Depending on the method of application of the load in bending distinguish pure and oblique bending.

torsional strain (бұрылу деформациясы)

Torsional strain - type strain, wherein the body is attached to the torque caused by the couple of forces acting in the plane perpendicular to the axis of the body. Torsional working machine shafts, screws and springs rigs.

Plastic and elastic deformation (пластикалық және серпімді деформация)

In the process of deformation is important value of the interatomic bonds, the application loads sufficient for their razyva leads to irreversible consequences (or irreversible plastic deformation). If the load does not exceed the allowable values​​, the body can return to its original state (elastic deformation). The simplest example of the behavior of subjects exposed to the plastic and elastic deformation, can be traced back to a fall from a height of a rubber ball and a piece of clay. A rubber ball is resilient, so it will shrink in the fall, and after the conversion of the energy of motion into heat, and the potential, again take its original shape. Clay has a great plasticity, so when it hits the surface irreversibly lose its original shape.

Mechanical voltage (механикалық кернеу) -a measure of internal forces generated in the deformable body, due to various factors. The mechanical stress at the body is defined as the ratio of the internal force per unit area at a given point of the section under consideration.

Absolute deformation (абсолют деформация) expresses the absolute change in a linear or angular dimension, or cross sectional area of the boundary surface of the portion allocated to the deformable body or the entire body.

Relative deformation (салыстырмалы деформация) characterizes the relative change in the same quantities. Typically, the relative deformation is defined as the ratio of the absolute change of any size to its original value.

When the deformation of the body there is a force that seeks to restore the previous size and shape of the body. This force arises because of the electromagnetic interaction between the atoms or molecules of matter. It is called by the elastic force.

For small deformations (| x | << l) the elastic force is proportional to the deformation of the body and is directed in the direction opposite to the direction of movement of the particles in the deformation of the body:

F_x = F _упр = – kx.

This ratio expresses the experimentally established Hooke's law. The coefficient k is called the rigidity of the body. The SI stiffness is measured in Newtons per meter (N / m). Stiffness coefficient depends on the shape and dimensions of the body and the material. In physics, Hooke's law for tensile or compressive strain is usually written in a different form. The ratio ε = x / l is called relative deformation, and the relation:

where S - the cross sectional area of the deformed body called voltage. Then Hooke's law can be stated as: the relative deformation ε is proportional to the stress

The coefficient E in this formula is called Young's modulus. The Young's modulus depends only on the material properties and does not depend on the size and shape of the body. Young's modulus of the various materials varies widely.

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