ANS:D - endurance limit

The maximum stress below which a material can withstand an infinite number of cycles of stress without failure is termed as the endurance limit. The endurance limit is a crucial property in materials engineering, particularly in the design of components subjected to cyclic loading, such as rotating machinery, bridges, and aircraft components. It represents the stress level at which a material can endure an indefinite number of stress cycles without fatigue failure. It's important to note that not all materials exhibit an endurance limit. For example, materials like steel typically have an endurance limit, while others like aluminum and titanium do not. In those cases, the concept of endurance limit is replaced by fatigue strength, which represents the stress level at which failure will occur after a finite number of stress cycles.