Question

A specimen is subjected to a stress which follows sinusoidal variation with respect to the time from minimum zero value to a maximum value \(+\sigma\):

1. Mean value of Stress = 0
2. Amplitude of Stress = \( \sigma / 2 \)
3. Nature of Stress = Repeated Stress
4. Nature of Stress = Fluctuating Stress

Choose the correct answer from the options given below:

• A. A, B and D only
• B. A,B and C only
• C. B and C only
• D. B and D only

Hint:

For sinusoidal variation the mean stress is zero amplitude is half of the maximum stress and the stress is considered fluctuating

Answer 1

The Correct Option is A

Given a sinusoidal stress variation from zero to a maximum value of \( \sigma \), we can deduce:

• The mean stress value is \( 0 \), as sinusoidal waves inherently average to zero.
• The stress amplitude is \( \frac{\sigma}{2} \), half of the maximum sinusoidal variation.
• This constitutes fluctuating stress, as it periodically varies over time between its minimum and maximum values.