Solid Deformation

The geometrical description of the part of the space filled by an object, as specified by its external limits, is called its shape. Deformation is defined as a change in shape caused by the application of force. Deformation is known to occur even when minimal forces are applied.

Deformation Process

Deformation is the change of a body from a reference configuration to a current configuration in continuum mechanics. A configuration is a set of all the positions of the body’s particles.

Strain is associated with deformation based on relative particle displacement in the body, excluding rigid-body motions. Depending on if the strain field is described with reference to the initial or final configuration of the body, or if the metric tensor or its dual is examined, several equivalent alternatives for the formulation of the strain field may be made.

A deformation field occurs in a continuous body as a result of a stress field caused by applied forces or variations in the body’s temperature field. Constitutive equations, such as Hooke’s law for linear elastic materials, depict the relationship between stress and strain. Elastic deformation is defined as a deformation that disappears after the stress field is eliminated. The continuum totally resumes its initial configuration in this situation. Irreversible deformations, on the other hand, persist. Even when all tensions have been removed, they still exist. Plastic deformation is one sort of irreversible deformation that occurs in material bodies after stresses reach a particular threshold value referred to as the elastic limit or yield stress, and is caused by slip or dislocation mechanisms at the atomic level. Viscous deformation, and that is the irreversible part of viscoelastic deformation, is another type of irreversible deformation. The compliance tensor of the material is the response function relating strain to the deforming stress in elastic deformations.

Stress and Its Types

Stress is referred to the force that acts on the per unit area of the material. Strength is described as the force acting on a unit area of a material in physics. As a result of stress, the body might become disordered. Stress units can be used to determine how much force has been applied to a material.

Remember that stress is a result of strain, thus stress is a reason for strain, and when a body does not see deformity as a result of the strain, it will not produce stress.

Types of Stress

Tensile Stress

The force per unit area is expressed as tensile stress. Because of the force, whenever stress is applied, the length of the body rises. If a rod is stretched in line with Newton’s third rule of motion, tensile stress is measured. It relates to the quantity of stretching. The symbol is commonly used to represent it.

Compression Stress

Whenever a tangential force is applied to a body, it changes its shape and volume. If compression tension is applied to the body, the length of the body is reduced. The reverse of compression stress is tensile stress. You’ve felt compressive stress on the body if you’ve ever squeezed a squeaky toy for your pet.

 Shearing Stress

Whenever the force applied is parallel to the body’s cross-sectional area, force per unit area is restored. Between opposing body faces, relative displacement arises.

Elastic/Young’s Modulus

The proportion of stress to strain is referred to as elastic modulus. The elastic modulus of each material is different. It means that the elastic modulus values of gold and rubber are not the same.

K=StressStrain

Here,

 k=Elastic modulus 

Features of Deformation in Solids 

The geometrical depiction of the part of the space filled by an object, as described by its external limits, is called its shape. Deformation is defined as a change in shape caused by the application of force. Deformation is known to occur even when minimal forces are applied.

Types of Deformation of Solids

Changes in shape (distortion) and volume (volume change) are two aspects of solid material deformation (dilatation). In solid materials, dilation is regarded as negligible. As a consequence, deformation is used interchangeably with dispersion.

Deformation can be either permanent or transient.

Permanent deformation is irreversible; it persists even after the applied forces are removed, but transitory distortion is recoverable since it diminishes after the applied forces are removed.

Elastic deformation refers to temporary deformation, whereas plastic deformation refers to permanent deformation.

Elastic deformation is time-dependent recoverable deformation during load, whereas elastic after-effect is the distinctive restoration of transitory deformation as a function of time after the load is removed.

Creep is the word denoting progressive, permanent distortion under constant load. Both reversible and permanent deformations exist in visco-elastic materials, and both are time dependent.

cube solid deformation

Conclusion

In continuum mechanics, deformation is the transformation of a body from its reference configuration to its current configuration. A configuration is a collection of all the particle positions in a body. Permanent deformation is irreversible; it remains even after the applied forces have been eliminated, whereas transient distortion is recoverable since it decreases after the applied forces have been removed.

Temporary distortion is referred to as elastic deformation, while permanent deformation is referred to as plastic deformation.