Definition - What does Mechanical Damage mean?
Mechanical damage is the loss of material due to a mechanical action.
Mechanical damage of pipeline can be defined as localized damage resulting from contact between the pipe and an object. Mechanical damage leads to material failure, and failure leads to fracture of materials.
Mechanical damage causes:
- Excessive deflection
- Ductile fracture/brittle fracture
- Relaxation/thermal shock
- Stress corrosion cracking (SCC)
Corrosionpedia explains Mechanical Damage
Mechanical damage is caused from mechanical wear and tear or actions.
The following types of damage can be caused by mechanical actions:
- Impact damage: Mechanical damage due to the impact of a projectile (bullet, shrapnel) or a hard tool
- Cut: Loss of material due to the action of an edge tool. It can have the appearance of an excavated cavity, an incision, a missing edge, etc.
- Scratch: Manually induced superficial and line-like loss of material due to the action of a pointed object. Usually it appears as a long groove.
- Abrasion: Erosion due to wearing down or rubbing away by means of friction, or to the impact of particles
- Keying: Impact damage resulting from hitting a surface with a pointed tool, in order to get an irregular surface which assists the adhesion of an added material, such as mortar
Mechanical damage leads to:
- Change of material shape
- Change in axial alignment
- Change of material properties
- Change to the local distribution of stresses strains, and/or local loading
- Introduction of other anomalies or defects to materials
Mechanical damage may occur during the manufacture, transportation, on-site handling and laying of materials. Usually such damage is found and remedied prior to service. However, some damage may not be detected until the material has been put into service.
Effect of Corrosion on a Material's Tensile Strength and Ductility