Machine Design Test 1 Exam Questions
and Answers 100% Solved | Rated A+
Fatigue Loading - ✔✔Occurs when a structure experiences dynamic,
fluctuating or variable loads
Fatigue - ✔✔an issue in any structure that is subjected to variable loading
(mechanical, pressure, or thermal); often the cause of many structure
failures
Fatigue Failure - ✔✔occurs due to excessive dynamic, repeated,
fluctuating or variable loading
What is a frequent cause of catastrophic failures? Why? - ✔✔Fatigue
Loading; it is poorly understood and difficult predict
Where do fatigue failures occur? - ✔✔Typically at stress levels significantly
lower that the yield strengths of the materials. Using static failure theories
can lead to unsafe designs when loads are dynamic
What are the two categories of fatigue? - ✔✔Low cycle
High cycle
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, Fatigue is caused by... - ✔✔Bending, torsional, axial, combined, thermal,
and pressure loads
Plastic Strain - ✔✔occurs when the stress at the discontinuity exceeds the
elastic limit
Material that exhibit a decreasing elastic limit - ✔✔Cold Drawn Steel
Material that exhibit an increasing elastic limit - ✔✔Annealed Steel
Coffin- Manson Relationship - ✔✔the sum of the elastic and plastic strain
amplitudes (total strain amplitude); the relationship between fatigue life and
total strain amplitude
What do S-N curves represent? - ✔✔average lifetime versus stress level
An unfinished rolled or forged element may _________________ or less of
the same part which has been ground and polished - ✔✔have half the
fatigue strength
Surface Factor Formula - ✔✔Cf=aSut^b
Impact - ✔✔a load applied suddenly which creates greater stresses in any
application than an equal load applied gradually
The size factor, Cs, for axial loading - ✔✔there is no size effect, therefore
Cs = 1
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
and Answers 100% Solved | Rated A+
Fatigue Loading - ✔✔Occurs when a structure experiences dynamic,
fluctuating or variable loads
Fatigue - ✔✔an issue in any structure that is subjected to variable loading
(mechanical, pressure, or thermal); often the cause of many structure
failures
Fatigue Failure - ✔✔occurs due to excessive dynamic, repeated,
fluctuating or variable loading
What is a frequent cause of catastrophic failures? Why? - ✔✔Fatigue
Loading; it is poorly understood and difficult predict
Where do fatigue failures occur? - ✔✔Typically at stress levels significantly
lower that the yield strengths of the materials. Using static failure theories
can lead to unsafe designs when loads are dynamic
What are the two categories of fatigue? - ✔✔Low cycle
High cycle
1
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
, Fatigue is caused by... - ✔✔Bending, torsional, axial, combined, thermal,
and pressure loads
Plastic Strain - ✔✔occurs when the stress at the discontinuity exceeds the
elastic limit
Material that exhibit a decreasing elastic limit - ✔✔Cold Drawn Steel
Material that exhibit an increasing elastic limit - ✔✔Annealed Steel
Coffin- Manson Relationship - ✔✔the sum of the elastic and plastic strain
amplitudes (total strain amplitude); the relationship between fatigue life and
total strain amplitude
What do S-N curves represent? - ✔✔average lifetime versus stress level
An unfinished rolled or forged element may _________________ or less of
the same part which has been ground and polished - ✔✔have half the
fatigue strength
Surface Factor Formula - ✔✔Cf=aSut^b
Impact - ✔✔a load applied suddenly which creates greater stresses in any
application than an equal load applied gradually
The size factor, Cs, for axial loading - ✔✔there is no size effect, therefore
Cs = 1
2
©JOSHCLAY 2024/2025. YEAR PUBLISHED 2024.
