Definition - What does Deformation mean?
In materials science, deformation refers to modifications of the shape or size of an object due to applied forces or a change in temperature.
Deformation is usually caused by forces such as:
- Tensile (pulling)
- Compressive (pushing)
- Torsion (twisting)
Deformation usually appears as strain.
Corrosionpedia explains Deformation
As deformation occurs, internal inter-molecular forces arise that oppose the applied force. If the applied force is not too high, these forces resist the applied force and allow the material to resume its original state once the load is removed. A larger applied force may cause a permanent deformation of the material, or even structural failure.
Different types of deformation may result from variations in type of material, size and the forces applied. Types of deformations include:
- Elastic deformation - This can be reversible. Elastomers and type memory metals like nitinol exhibit huge elastic deformation ranges, as does rubber.
- Plastic deformation - This may be irreversible. Soft thermoplastics have a rather large plastic deformation variance, as do ductile metals such as copper, silver and gold.
- Metal fatigue - This occurs primarily in ductile metals. Metal fatigue has been a common cause for failure, especially before the process was well understood.
- Compressive failure -This is applied to bars, columns, etc., which leads to shortening. Loading a structural object or specimen can increase the compressive stress until it reaches its compressive strength.
- Fracture - This may be irreversible. All materials eventually fracture, if enough force is applied.
The Effects of Stress Concentration on Crack Propagation