Elastic behavior

When the sling is stretched, it deforms due to the applied force, and when the force called elasticity is stopped, it returns to its original shape. That is, when stressed, the body resists permanent changes.

The body returns to its original shape and size when the applied stress is removed. Let’s say you have a thin steel rod that can bend. Do not apply force if it bends a little. The rod does not return to its original shape. You can recognize different behaviors of a material based on its elastic and plastic properties. 

The ability of an object to withstand permanent changes under load is known as elasticity. Different materials have different elastic behaviors. 

Application of elastic behavior of materials

 The elastic theory is used to design safe and stable man-made structures such as skyscrapers and bridges to make life comfortable. The hoisting crane uses ropes designed so that the maximum load loads do not exceed the rupture stress. 

It has also been found that the accumulation of thin wire strands, when compressed, makes the rope stronger than a solid rope of the same cross-section. For this reason, crane ropes are made of multiple strands rather than a single strand. 

Structures such as bridges and skyscrapers that must support static or dynamic loads are usually constructed with columns and beams to support them. Beams used in buildings and bridges must be carefully constructed so that they do not bend excessively or break under stress. 

Beams and columns are designed to be stable and safe within the designed maximum load capacity.

Elastic behavior of solids

The following paragraph describes the elastic behavior of solids:

When a solid is exposed to an external force, the object deforms, and the atoms and molecules that make it deviate from its original positions and out of equilibrium. The shift changes the fixed point, changing both the interatomic and intramolecular distances. Therefore, deformation can be called a change in the structure of an object due to the influence of the force acting on the object. The force that moves these particles is called the deforming force. 

Because we know that all forces have equal and opposite forces, the deforming force opposes the restoring force acting in the opposite direction, this force pushes the body back to its original position when the deforming force is removed. The spring ball system contains balls representing atoms and springs representing the forces acting between them.

Linear elastic behavior

Only two material parameters, Young’s modulus (E) and Poisson number (ν) need to be determined experimentally. The modulus of elasticity can be obtained directly from a uniaxial tensile or compression test. 

The linear elastic behavior envisions the idealization of the linear elasticity and the crack problem to very low yield strengths. This requires Hooke’s law to be applied without limiting the magnitude of stress or strain.

The stress-strain field near the crack edge is uniquely determined for each mode by the stress intensity factor. Here, finding this factor is the main goal, but other field characteristics such as crack openings are also investigated from time to time. 

 The term “small yield” is used in the current work in two slightly different senses, depending on how the actual case of small yield is idealized. In one sense, the dissipated area is considered infinitely small, and the length of the crack is considered finite; in another sense, the dissipated area is considered to be finite, and the length of the crack is considered to be infinite. 

The first idealizations used in this chapter are suitable for investigating elastic stress-strain fields in cracked objects. The latter idealization is suitable for investigating the plastic region of the crack edge. 

A brief review suggests the opposite emphasis. The crack problems that analytical techniques can attack form a very limited subset of the vast number of important problems in engineering, geophysics, and related disciplines. 

However, experience has shown that numerical methods cannot be meaningful without a deep knowledge of analytical methods and results. These are often used to control the accuracy of numerical methods. In addition, analytical techniques often lead to better insights into the general characteristics of the phenomenon under study.

Conclusion

When exposed to external forces, all rigid bodies in the universe change their physical orientation and structure. A rigid body changes its length, volume, or shape when an outward force is applied. 

The body retains its original shape and size even when there is no external force. Therefore, elasticity is a characteristic of the body that returns everyone to their original shape (or size) when the external force is removed. It shows resistance to change. Example: A rubber band.