Question

The ability of materials to develop a characteristic behaviour under repeated loading is

• A. Fatigue
• B. Hardness
• C. Resilience
• D. Toughness

Hint:

Associate key loading conditions with material properties:
- Repeated/Cyclic Load $\rightarrow$ Fatigue.
- Static Indentation/Scratch $\rightarrow$ Hardness.
- Energy Absorption (Elastic) $\rightarrow$ Resilience.
- Energy Absorption (Plastic, before fracture) $\rightarrow$ Toughness.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks for the term that describes a material's behavior when subjected to repeated or cyclic loading.

Step 2: Detailed Explanation:
Let's define the given material properties:

• (A) Fatigue: This is the weakening of a material caused by repeatedly applied loads (cyclic loading). It is the progressive and localized structural damage that occurs when a material is subjected to cyclic loading. Fatigue failure often occurs at a stress level significantly lower than the ultimate tensile strength of the material. This exactly matches the description in the question.

• (B) Hardness: This is a measure of a material's resistance to localized plastic deformation such as scratching or indentation. It is typically measured under a static load.

• (C) Resilience: This is the ability of a material to absorb energy when it is deformed elastically and release that energy upon unloading.

• (D) Toughness: This is the ability of a material to absorb energy and plastically deform without fracturing. It is a measure of a material's resistance to fracture when a crack is present.


The key phrase in the question is "repeated loading," which is the definition of the conditions that lead to fatigue.

Step 3: Final Answer:
The ability of materials to develop a characteristic behaviour under repeated loading is known as fatigue.