Question

The resistance to fatigue of a material is measured by?

Answer 1

Hint: Cycle number is mentioned in the endurance limit. Fatigue limit is the load limit below which material gains infinite life. Fatigue limit could be measured by a fatigue test. For the Steel (Se) typically values of the limit are \[42\] the ultimate tensile strength to a maximum of \[290MPa\left( {42ksi} \right)\].

Complete step-by-step solution:
By the endurance limit, the resistance of a material to fatigue is measured. The fatigue of a substance is the stress or pressure it undergoes as it is exposed to repetitive processes or cycles that lead to its structure breakdown and the material eventually fracturing. Without cracking or splitting for a certain number of cycles the maximum or the highest strength of is the fatigue strength that a substance can withstand and such strength is also calculated by endurance limit. Hence the right answer is the endurance limit. Different types of stress are normal stress and tensile stress. When subjected to repeated processes or cycles the fatigue of a material is the stress or strain it undergoes which leads to the breakdown of its structure and ultimately fracture of the material. For a certain number of cycles without breaking or fracturing the fatigue strength is the highest or maximum strength that a material can withstand. This strength is known as and measured by endurance limit.

Note: Endurance limit concept was introduced by August Wohler in \[1870\]. Without complaining for a long period of time the ability to continue doing something painful or difficult is known as endurance. On surface roughness and size of beam endurance limit depends.