impact of external forces on any body leads to a variety of consequences.Object effects can get acceleration and start moving.In the process of moving or at rest within it may occur some changes, which are called "deformation".
word "deformation" comes from the Latin deformatio, which means "distortion."Under this concept taken to mean a process which occurs as a result of change in the relative positions of the particles of the body, that is, the particles themselves are moved relative to each other.The deformation as a result of changes in the distance interatomic distances leads to a rearrangement of blocks of atoms.Often it is associated with a change in the values of interatomic forces.The measure of deformation is the mechanical stress.Because of the deformation body can obtain the following effects which are, or may recover by acquiring former state that he had up to outside influences.
If the body regains its form, this type of deformation is called elastic.The elastic deformation as said specialized literature, a deformation which disappears after the external forces ceases.The body gets back into shape, its dimensions are reduced.
This definition is taken from the branch of physics studying the elastic deformation, which is called the theory of elasticity.The elastic deformation has a distinctive feature: its value is not based on the previous history, mechanical stress is the root cause of it.In other words, it is entirely defined and depends on the mechanical stresses.In most substances this dependence with a high accuracy is considered to be directly proportional.The elastic deformation is strictly obeys certain physical law, he is still known as Hooke's law.The maximum voltage at which the elastic deformation of the law remains valid, is called the limit of proportionality.
Some materials (rubbers, metals) have the exclusive property of withstanding significant levels of elastic deformation, for other substances (pressed materials, ceramics) very small elastic deformation can not be.The maximum mechanical stress, deformation in which even falls under the definition, called the yield stress.Overcoming this value, the elastic deformation turns into plastic.
Due to the strain that has elastic properties and recurrent, there is a phenomenon called elastic vibrations.When the elastic vibrations are starting to spread, this phenomenon is called the elastic waves.
Considering the elastic deformation should not forget that the elastically deformed body has a certain amount of energy.Elastic energy refers to the mean energy of position, or in other words, a potential.Elastically deformable body is able to perform some work, restoring its former state.Ideally, the value of this work is the amount of work expended in the process of deformation.
Due to its elastic deformation properties is widely spread in practical life.A great value in a variety of mechanical devices is the use of parts whose function depends on their ability to deform elastically.Some of them store energy, for example, the winding spring in a mechanical watch, others soften the impact of external forces on the device (shock absorbers, springs).
During the creation of different mechanisms, it was observed that the property to be deformed elastically affects not only the material from which is made one or other item, but also the processing which it has passed.
