What is deformation of a body?
Linear Theory of Infinitesimal Deformations Deformation is a change of the dimensions and in some case shape of a body due to an applied external force.
What are 2 types of deformation?
Deformation can be of two types as follows:
- Permanent Deformation – Also known as plastic deformation, it is irreversible. It is a type of deformation that stays even after the removal of applied forces.
- Temporary Deformation – Also known as elastic deformation, it is reversible.
Is permanent deformation considered failure?
These can be a result of compressive forces, tensile forces, shear, bending or torsion (twisting). Plastic deformation is not recoverable. However, an object in the plastic deformation range will first have undergone an elastic deformation, which is recoverable, so the object will return part way to its original shape.
What damage can plastic strain cause?
The internal structure is subject to plastic deformation and damage evolution, which leads to the degradation of the mechanical property. Therefore, the strength of the clastic reservoir is evidently reduced, thereby causing casing damage and a large deformation of the reservoir [9–16].
Is plastic deformation good or bad?
The main effect of any Severe Plastic Deformation (SPD) technique is the increase of mechanical strength due to grain size reduction, and among those techniques only Equal Channel Angular Pressing (ECAP) is capable of producing billets of commercial dimensions.
Where does plastic deformation occur?
Plastic deformation is the permanent distortion that occurs when a material is subjected to tensile, compressive, bending, or torsion stresses that exceed its yield strength and cause it to elongate, compress, buckle, bend, or twist.
How does plastic deformation occur?
What is plastic behavior?
For stresses beyond the elastic limit, a material exhibits plastic behavior. This means the material deforms irreversibly and does not return to its original shape and size, even when the load is removed. When stress is gradually increased beyond the elastic limit, the material undergoes plastic deformation.
Is plastic deformation reversible?
In physics and materials science, plasticity, also known as plastic deformation, is the ability of a solid material to undergo permanent deformation, a non-reversible change of shape in response to applied forces.
What is plastic strain?
This type of strain is caused by rearrangement of the atoms in the material and is not reversible. When the stress is removed the plastic deformation remains in the material.
How do you know if a plastic strain is fractured?
The plastic strain is obtained by subtracting the elastic strain, defined as the value of true stress divided by the Young’s modulus, from the value of total strain (see Figure 1). Figure 1. Decomposition of the total strain into elastic and plastic components.
What is plastic strain ratio?
Plastic strain ratio r is a measure of the ability of a sheet metal to resist thinning or thickening when subjected to a tensile or compressive force. To determine this ratio, assuming constant volume, both the axial and transverse strain needs to be obtained during a uni-axial tensile test. …
What is effective plastic strain?
Effective plastic strain is a monotonically increasing scalar value which is calculated incrementally as a function of (Dp)ij, the plastic component of the rate of deformation tensor.
What is permanent strain?
: a strain that develops within a body upon rapid or nonuniform solidification and that may be removed by careful annealing.
What is the difference between elastic strain and plastic strain?
Elastic deformation is a temporary deformation under the action of external loading. Plastic deformation is the permanent deformation. Once the external load is removed from an elastically deformed body, it regains its original shape. Elastic deformation is characterized by the property Elasticity.