Machine Design Test 1- Exam Questions with 100%
Correct Answers| Verified-
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
Brittle Fracture - ✔✔A strong possibility when operating temperatures are below
room temperatures and should be investigated first under these circumstances
Yield - ✔✔should be investigates first when the operating temperature is higher than
room temperature; Yield strength drops off rapidly with increased temperature
Creep - ✔✔will be induced in a material operating at high temperatures
, Endurance limit for steels increases slightly...... - ✔✔when the operating temperature
rises to 400F and then begins to decrease in the 400-700 F range
Fatigue Stress Concentration Factor - ✔✔must be used when designing against
fatigue
When can you not used a Fatigue Stress Concentration Factor? - ✔✔In ductile
materials or materials that act as if they are ductile
Notch Sensitivity - ✔✔a measure of how a material reacts due to the presence of a
notch
Fatigue Loading Failure Criteria - ✔✔Soderberg, Modified Goodman, Gerber, Yielding
Screws and Bolts - ✔✔used to hold things together as fasteners; can be arranged to
take tensile loads, shear loads, or both
Power Screws and Lead Screws - ✔✔used to move loads
Major Diameter - ✔✔largest diameter of screw thread
Minor Diameter - ✔✔smallest diameter of screw thread
Pitch - ✔✔1/N; N= # of threads per inch
Lead - ✔✔the distance the nut travels parallel to screw axis per revolution
Correct Answers| Verified-
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
Brittle Fracture - ✔✔A strong possibility when operating temperatures are below
room temperatures and should be investigated first under these circumstances
Yield - ✔✔should be investigates first when the operating temperature is higher than
room temperature; Yield strength drops off rapidly with increased temperature
Creep - ✔✔will be induced in a material operating at high temperatures
, Endurance limit for steels increases slightly...... - ✔✔when the operating temperature
rises to 400F and then begins to decrease in the 400-700 F range
Fatigue Stress Concentration Factor - ✔✔must be used when designing against
fatigue
When can you not used a Fatigue Stress Concentration Factor? - ✔✔In ductile
materials or materials that act as if they are ductile
Notch Sensitivity - ✔✔a measure of how a material reacts due to the presence of a
notch
Fatigue Loading Failure Criteria - ✔✔Soderberg, Modified Goodman, Gerber, Yielding
Screws and Bolts - ✔✔used to hold things together as fasteners; can be arranged to
take tensile loads, shear loads, or both
Power Screws and Lead Screws - ✔✔used to move loads
Major Diameter - ✔✔largest diameter of screw thread
Minor Diameter - ✔✔smallest diameter of screw thread
Pitch - ✔✔1/N; N= # of threads per inch
Lead - ✔✔the distance the nut travels parallel to screw axis per revolution
