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Q3: wala sa choices yung sagot kaya yan nalng hahah
When a material is subjected to fatigue loading, the ratio of its ultimate tensile strength to
its endurance limit is ___.
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a 1.6
. 7
b 0.6
.
c 2.0
.
d 0.5
.
The endurance or fatigue limit is defined as the maximum value of the stress which a
polished standard specimen can withstand without failure, for infinite number of cycles,
when subjected to ___.
a fluctuating load
.
b repeated load
.
c completely reversed
. load
d varying load
.
If the size of a standard specimen for a fatigue testing machine is increased, the
endurance strength of the material will ___.
a increase
.
b double
.
c decrease
.
d have same
.
value as that of standard
specimen
Find the surface factor for a machine member with ground surface and ultimate strength
for shear of 60,000 psi.
a 0.9
. 4
b 0.9
. 0
c 0.9
. 5
d 0.9
. 2
If the size of a standard specimen for a fatigue testing machine is decreased, the
endurance strength of the material will ___.
a double
.
b have same
value as that of standard
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.
specimen
c increase
.
d decrease
.
The resistance to fatigue of a material is measured by
a elastic limit
.
b endurance limit
.
c Modulus of
. Elasticity
d ultimate point
.
Which pressure vessel is strongest?
a spherical vessel
.
b cylindrical vessel
.
c semi-spherical
. vessel
d elliptical vessel
.
Line joining Sy (yield strength of the material) on mean stress axis and Sn’ (endurance
limit of the component) on stress amplitude axis is called as _____.
a Soderberg Line
.
b Goodman Line
.
c Line of Safe
. Stress
d Gerber Line
.
Which failure criterion is applicable when failure criterion is not assumed and the mean
stress and alternating stress are non-zero?
a Gerber criterion
.
b Soderberg criter
. ion
c Goodman
. criterion
d none in the list
.
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The surface finish factor for a machine member with sharp circular notch and ultimate strength of
approximately 861.6 MPa is ___.
a 0.6
. 2
b 0.6
. 1
c 0.6
. 5
d 0.6
. 8
The longitudinal stress is ___ of the circumferential stress.
a one. fourths
b twice
.
c one-half
.
d three. fourths
The design of the thin-walled pressure vessel is based on
a longitudinal stress
___.
.
b longitudinal transverse
. stresses
c longitudinal and girth
. stresses
d hoop stress
.
Failure of a material is called fatigue when it fails ___.
a below the yield
. point
b at the yield point
.
c below the elastic
. limit
d at the elastic limit
.
The constant a for a steel material having an ultimate strength of 106.5 ksi is ___.
a 0.0003438
.
b 0.003498
.
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c 0.00438
.
d 0.000348
.
A rectangular plate, 30mm by 60 mm is subjected to a tensile force of 5kN in the
direction of the plate’s larger side. The plate has a circular hole at the center with
diameter of 15mm. If stress concentration factor=2.16, find the thickness of the plate if
maximum allowable tensile stress is 80N/mm².
a 12
. mm
b 10
. mm
c 8 mm
.
d 9 mm
.
A machine member made of brittle material is subjected to varying torsional loads where
the alternating stress is 34000 psi. The material’s endurance strength and the mean
stress can be taken as 85 ksi and 42.5 ksi, respectively. For a factor of safety based on
Goodman criterion of 1.8, estimate the ultimate strength of the material in psi.
a 27321
. 4
b 34628
. 6
c 76500
.
d 10200
. 0
A seamless cylinder of storage capacity of 0.03m3 is subjected to an internal pressure of
21 MPa. The ultimate strength of material of cylinder is 350N/mm².Determine the length
of the cylinder if it is twice the diameter of the cylinder.
a 270
. mm
b 350
. mm
c 540
. mm
d 400
. mm
A machine member made of steel is subjected to repeated axial loads where the mean
stress is 23500 psi. The material’s ultimate strength can be taken as 162 ksi and the
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endurance strength as 58 ksi. For a factor of safety based on Soderberg criterion of 1.6,
estimate the yield strength of the material in psi.
a 70175
.
b 64141
.
c 106902
.
d 98356
.
A seamless cylinder of storage capacity of 0.03m3 is subjected to an internal pressure of
21 MPa. The allowable stress in the material of cylinder is 350N/mm².Determine the
length of the cylinder if it is twice the diameter of the cylinder.
a 4 mm
.
b 12
. mm
c 8 mm
.
d 6 mm
.
If a certain type of steel has an ultimate strength of 185 ksi, calculate the value of
constant a for the material.
a 0.000348
.
b 0.00438
.
c 0.0003438
.
d 0.000438
.
Determine the bursting steam pressure of a steel shell with diameter of 10 inches and
made 1/4 in thick steel plate. The joint efficiency is 70%and the tensile strength is 60
ksi.
a 42.8
. ksi
b 4200
. psi
c 8500
. psi
d 10.5
. ksi
A spherical air tank stores air at 3000 psig. The tank is to have an inside diameter of 7 in. What should be
the wall thickness of the tank if it is made of AISI 301, ¼-hard stainless steel (Sy = 75 ksi), with a design
factor of 1.5 based on the yield strength and a joint efficiency of 90%.
a 0.21 in.
.
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b 0.189
. in.
c 0.2333
. in.
d 0.1167
. in.
A circular rod made of ductile material with a fatigue strength, S n= 280 MPa and a
tensile yield strength of 350 MPa. The member is subjected to a varying axial load from
700 kN to – 300 kN. Assume Kf = 1.8 and F.S. = 2. Calculate the alternating stress S a in
terms of the diameter in MPa.
a 2800000/πd2
.
b 2000000/πd2
.
c 1200000/πd2
.
d 800000/πd2
.
A shaft is to be subjected to a maximum reversed torque of 15,000 in-lb. It is machined
from AISI 3140 steel, OQT 1000 F. Considering that the endurance strength is
approximately 40% of the endurance limit, what should be its diameter for N =1.75?
a 1.21
. in.
b 1.64
. in.
c 1.26
. in.
d 1.71
. in.
A 1 ½-in. shaft is made of AISI 1045 steel, as rolled with Sy=59 ksi. For N = 2, what
reversed torque can the shaft sustain indefinitely? Assume Endurance Strength as
21050 psi.
a 4287 in-bs
.
b 6975 in-lbs
.
c none in the
. list
d 6976 in-lbs
.
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