Which property measures the amount of energy a material can absorb before fracture?

• A. Hardness
• B. Toughness
• C. Fatigue Life
• D. Ductile to Brittle Transition

Answer: (B)

Toughness is the amount of energy a material can absorb before fracture. It reflects how much work the material can do while being loaded up to the point of crack initiation and crack propagation, essentially the area under the stress–strain curve up to failure. Materials with high toughness can undergo substantial plastic deformation and still carry load, soaking up a lot of energy before breaking. In contrast, a brittle material absorbs little energy and tends to fracture with minimal plastic deformation.

This concept is different from hardness, which measures resistance to surface indentation and does not indicate how much energy the material can absorb in a fracture event. It’s also distinct from fatigue life, which is about how many loading cycles a material can endure before failure under repeated loading, and from the ductile-to-brittle transition, which describes how fracture mode changes with temperature rather than the total energy absorbed before fracture.