Question

The property that cannot be obtained from a tensile test is

• A. Yield Strength
• B. Ultimate Tensile Strength
• C. Ductility
• D. Endurance Limit

Hint:

Tensile tests measure static mechanical properties.
Dynamic or cyclic properties (like fatigue life, endurance limit, and impact toughness) require separate specialized tests such as fatigue testing machines and Charpy/Izod impact testers.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
The question asks to identify which of the given mechanical properties of a material cannot be determined by conducting a standard uniaxial tensile test on a universal testing machine (UTM).

Step 2: Detailed Explanation:

• Standard Tensile Test capabilities:
During a uniaxial tensile test, a specimen is subjected to a slowly increasing static or quasi-static tensile load until it fractures.
The resulting engineering stress-strain curve allows direct determination of:
1. Yield Strength: The stress at which a material transitions from elastic to plastic deformation. Option (A) is obtained.
2. Ultimate Tensile Strength: The maximum stress value on the engineering stress-strain curve. Option (B) is obtained.
3. Ductility: Measured quantitatively by percent elongation ($\%EL$) and percent reduction in area ($\%RA$) at fracture. Option (C) is obtained.

• Endurance Limit:
The endurance limit (or fatigue limit) is the maximum amplitude of cyclic stress that a material can withstand for an infinite number of load cycles without experiencing fatigue failure.
Fatigue represents a dynamic, time-dependent failure mechanism under fluctuating loads.
Because a tensile test is a monotonic, static test, it cannot capture cyclic fatigue behavior.
To find the endurance limit, a dedicated fatigue test (such as the rotating-beam test) must be conducted to plot an S-N curve.

Step 3: Final Answer:
The endurance limit cannot be obtained from a tensile test.