Subtopic: Measurement of force, stress, torque, speed, displacement and acceleration on machine elements – shafts, couplings, keys, bearings and knuckle joints
Question Statement:
In the design of a knuckle joint connecting two rods under axial tensile load $P$, the failure mode of the knuckle pin under shear is typically characterized as:
Options:
(A) Single shear failure
(B) Double shear failure
(C) Torsional shear failure
(D) Buckling failure
Answer Key:
B
Step-by-Step Solution & Explanation
The pin passes through the single eye of one rod and the double fork/eye of the second rod. Under axial tension, the pin is subjected to double shear at the two interfaces between fork and single eye: $\tau = \frac{P}{2 \times (\frac{\pi}{4} d^2)}$.