Elastic and Inelastic Materials

Elastic and Inelastic Materials

Elastic Materials

• Materials that return to their original shape and size after an external force is removed
• Deformation is temporary and reversible
• Stress and strain are directly proportional (Hooke's Law)
• Examples:
  • Metals (e.g. copper, iron, aluminum)
  • Some plastics (e.g. polyethylene, polypropylene)
  • Rubber
  • Biological tissues (e.g. skin, muscle, bone)

Inelastic Materials

• Materials that do not return to their original shape and size after an external force is removed
• Deformation is permanent and irreversible
• Stress and strain are not directly proportional
• Examples:
  • Clay
  • Soil
  • Some plastics (e.g. polyvinyl chloride, PVC)
  • Biological tissues (e.g. cartilage, tendon)
• Subcategories:
  • Plastic materials: deform permanently under stress, but do not break (e.g. clay, putty)
  • Brittle materials: break or shatter under stress (e.g. glass, ceramics)

Elastic Materials

• Materials that return to their original shape and size after an external force is removed, exhibiting temporary and reversible deformation
• Stress and strain are directly proportional, following Hooke's Law
• Examples of elastic materials include metals (e.g. copper, iron, aluminum), certain plastics (e.g. polyethylene, polypropylene), rubber, and biological tissues (e.g. skin, muscle, bone)

Inelastic Materials

• Materials that do not return to their original shape and size after an external force is removed, undergoing permanent and irreversible deformation
• Stress and strain are not directly proportional
• Examples of inelastic materials include clay, soil, certain plastics (e.g. polyvinyl chloride, PVC), and biological tissues (e.g. cartilage, tendon)
• Inelastic materials can be further classified into two subcategories:

Plastic Materials

• Deform permanently under stress, but do not break (e.g. clay, putty)

Brittle Materials

• Break or shatter under stress (e.g. glass, ceramics)