Q1: The yield point in fatigue loading compared to that in static loading is less. The ratio of ultimate tensile strength to endurance limit of a material subjected to fatigue loading is

ANS:D - 2

The ratio of ultimate tensile strength (UTS) to endurance limit (also known as fatigue limit) of a material subjected to fatigue loading is typically greater than 1. Explanation:

1. Ultimate Tensile Strength (UTS): UTS is the maximum stress that a material can withstand before failure under tensile loading conditions. It represents the maximum strength of the material under static loading.
2. Endurance Limit (Fatigue Limit): The endurance limit is the maximum stress amplitude that a material can sustain indefinitely without failing under cyclic loading conditions. It represents the stress level below which the material can endure an infinite number of cycles without fatigue failure.
3. Yield Point in Fatigue Loading: In fatigue loading, materials typically exhibit a lower yield point compared to static loading. This is because fatigue loading involves cyclic stresses, which can lead to the initiation and propagation of microscopic cracks even at stress levels below the yield point observed in static loading.
4. Ratio of UTS to Endurance Limit: The ratio of UTS to endurance limit varies depending on the material and its properties. However, in most cases, the UTS is higher than the endurance limit. This is because the UTS represents the maximum strength of the material under static loading conditions, whereas the endurance limit represents the maximum cyclic loading capacity of the material without fatigue failure. Therefore, the ratio of UTS to endurance limit is typically greater than 1.