The elastic materials are those materials that have the ability to resist a distorting or deforming influence or force, and then return to their original shape and size when the same force is withdrawn.
Linear elasticity is widely used in the design and analysis of structures such as beams, plates, and sheets. Elastic materials have great importance for society, since many of them are used to make clothes, tires, automotive parts, etc..
Article index
When an elastic material is deformed with an external force, it experiences internal resistance to deformation and restores it to its original state if the external force is no longer applied..
To some extent, most solid materials exhibit elastic behavior, but there is a limit to the magnitude of the force and the attendant deformation within this elastic recovery..
A material is considered elastic if it can be stretched up to 300% of its original length. For this reason, there is an elastic limit, which is the greatest force or tension per unit area of a solid material that can withstand a permanent deformation..
For these materials, the yield point marks the end of their elastic behavior and the beginning of their plastic behavior. For weaker materials, stress or strain on their yield point results in their fracture..
The elasticity limit depends on the type of solid considered. For example, a metal bar can be elastically extended up to 1% of its original length..
However, fragments of certain rubbery materials can experience extensions of up to 1000%. The elastic properties of most intent solids tend to fall between these two extremes..
You may be interested in How is an Elastic Material Synthesized??
In physics, a Cauchy elastic material is one in which the stress / tension of each point is determined only by the current state of deformation with respect to an arbitrary reference configuration. This type of material is also called simple elastic material..
Based on this definition, the stress in a simple elastic material does not depend on the deformation path, the history of the deformation, or the time it takes to achieve that deformation..
This definition also implies that the constitutive equations are spatially local. This means that stress is only affected by the state of the deformations in a neighborhood close to the point in question..
It also implies that the force of a body (such as gravity) and the forces of inertia cannot affect the properties of the material..
Simple elastic materials are mathematical abstractions, and no real material fits this definition perfectly..
However, many elastic materials of practical interest, such as iron, plastic, wood, and concrete, can be assumed to be simple elastic materials for stress analysis purposes..
Although the stress of simple elastic materials depends only on the state of deformation, the work done by stress / stress can depend on the deformation path.
Therefore, a simple elastic material has a non-conservative structure and stress cannot be derived from a scaled elastic potential function. In this sense, materials that are conservative are called hyperelastic..
These elastic materials are those that have a constitutive equation independent of the finite stress measurements except in the linear case.
The models of hypoelastic materials are different from the models of hyperelastic materials or of simple elastic materials since, except in particular circumstances, they cannot be derived from a function of deformation energy density (FDED).
A hypoelastic material can be rigorously defined as one that is modeled using a constitutive equation that satisfies these two criteria:
As a special case, this criterion includes a simple elastic material, in which the current stress depends only on the current configuration rather than the history of past configurations..
These materials are also called Green's elastic materials. They are a type of constitutive equation for ideally elastic materials for which the stress relationship is derived from a strain energy density function. These materials are a special case of simple elastic materials.
For many materials, elastic linear models do not correctly describe the observed behavior of the material..
The most common example of this class of material is rubber, whose stress-tension relationship can be defined as non-linear, elastic, isotropic, incomprehensible, and generally independent of its stress ratio..
Hyperelasticity provides a way to model the stress-tension behavior of these materials..
The behavior of void and vulcanized elastomers often make up the hyperelastic ideal. Filled elastomers, polymeric foams, and biological tissues are also modeled with hyperelastic idealization in mind..
Hyperelastic material models are regularly used to represent high-strain behavior in materials..
They are usually used to model full and empty elastomer and mechanical behavior.
1- Natural rubber
2- Spandex or lycra
3- Butyl rubber (PIB)
4- Fluoroelastomer
5- Elastomers
6- Ethylene-propylene rubber (EPR)
7- Resilin
8- Styrene-butadiene rubber (SBR)
9- Chloroprene
10- Elastin
11- Rubber epichlorohydrin
12- Nylon
13- Terpene
14- Isoprene rubber
15- Poilbutadiene
16- Nitrile rubber
17- Stretch vinyl
18- Thermoplastic elastomer
19- Silicone rubber
20- Ethylene-propylene-diene rubber (EPDM)
21- Ethylvinylacetate (EVA or foam rubber)
22- Halogenated butyl rubbers (CIIR, BIIR)
23- Neoprene
Yet No Comments