Question 1:Endurance limit of a beam subjected to pure bending decreases with
[2019 , Set 2]
Question 2:A cylindrical shaft is subjected to an alternating stress of 100 MPa. Fatigue strength to sustain 1000 cycles is 490 MPa. If the corrected endurance strength is 70 MPa, estimated shaft life will be
By concept of straight line,
At y = 2
⇒ x = 5.4501
log10N = 5.4501, N = 281914
Question 3:The S-N curve for steel becomes asymptotic nearly at
Question 4:In terms of theoretical stress concentration factor kt and fatigue stress concentration factor kt, the notch sensitivity q is expressed as
Question 5:Which one of the following is the most conservation fatigue failure criterion?
Question 6:A static load is mounted at the centre of a shaft rotating at uniform angular velocity. This shaft will be designed for
Shaft will be designed for fatigue loading.
Question 7:The yield strength of a steel shaft is twice its endurance limit. Which of the following torque fluctuations represent the most critical situation according to Soderberg criterion?
τa is highest in (a)
Question 8:The process of shot peening increases the fatigue life of steel springs mainly because it results in
Shot preening increases fatigue life of springs
Question 9:Stress concentration in a machine component of a ductile material is not so harmful as it is in a brittle material because
Local yielding reduces stress concentration effect.
Question 10:A ductile material having an endurance limit of 196 N/mm2 and the yield point at 294 N/mm2 is stressed under variable load. The maximum and minimum stresses are 147 N/mm2 and 49 N/mm2. The fatigue stress concentration factor is 1.32. The available factor of safety for this loading is
Consider Soderberg equation
FOS = 1.5