Which is correct statement? Stress concentration in static loading is
Very serious in brittle materials and less serious in ductile materials
Very serious in ductile materials and less serious in brittle materials
Equally serious in both types of materials
Seriousness would depend on other factors
Correct Answer :
A. Very serious in brittle materials and less serious in ductile materials
Related Questions
The notch sensitivity q is expressed in terms of fatigue stress concentration factor Kf and theoretical stress concentration factor Kt as
(Kf + 1)/ (Kt + 1)
(Kf - 1)/ (Kt - 1)
(Kt + 1)/ (Kf + 1)
(Kt - 1)/ (Kf - 1)
The material used for brake lining should have __________ coefficient of friction.
Low
High
Moderate
None of these
The design of shafts made of brittle materials is based on
Guest's theory
Rankine's theory
St Venant's theory
Von Mises theory
If a shaft made from ductile material is subjected to combined bending and twisting moment, calculations based on which one of the following failure theories will give the most conservative value?
Maximum principal stress theory
Maximum shear stress theory
Maximum strain energy theory
Maximum distortion energy theory
Cast iron pipes are mainly used
For conveying steam
In water and sewage systems
In pressure lubrication systems on prime movers
All of the above
A key way lowers
The strength of the shaft
The rigidity of the shaft
Both the strength and rigidity of the shaft
The ductility of the shaft
Ball bearing type screws are found in following application
Screw jack
Aeroplane engines
Crane
Steering mechanism
The connecting rod bolts are tightened up with initial tension greater than the external load so that
Joint may not open up
Bolts are weakest elements
The resultant load on the bolt would not be affected by the external cyclic load
Bolts will not loosen during service
For steel, the ultimate strength in shear as compared to ultimate strength in tension is
1/2
1/3
1/4
2/3
A spring of stiffness 1000 N/m is stretched initially by 100 mm from the undeformed position. The work required to stretch it by another 100 mm is
5 N-m
7 N-m
10 N-m
15 N-m
When the connected members are very yielding (soft gasket) as compared to the bolt, then the resultant load on the bolt will be equal to the
Initial tension
External load applied
Sum of the initial tension and external load applied
Initial tension or external load, whichever is greater
Plastic flow in ductile materials
Increases the seriousness of static loading stress concentration
Lessens the seriousness of static loading stress concentration
Has no effect on it
Depends on other considerations
In order to determine the stresses in a thin cylinder due to an internal pressure, it is assumed that
The effect of curvature of the cylinder wall is neglected
The tensile stresses are uniformly distributed over the section of the walls
The effect of the restraining action of the heads at the end of the pressure vessel is neglected
All of the above
According to I.B.R., shearing resistance required to shear off the rivet per pitch length (in double shear) is (where n = Number of rivets per pitch length)
(π/4) d² × τ × n
1.875 × (π/4) d² × τ × n
2 × (π/4) d² × τ × n
3 × (π/4) d² × τ × n
The included angle for the British Association thread is
29°
55°
47.3°
60°
A thin spherical shell of internal diameter d is subjected to an internal pressure p. If V is the storage capacity of shell, then its diameter will be
(6V/ π)1/2
(6V/ π)1/3
(6V/ π)2
(6V/ π)3
The steel pulleys are __________ in weight than cast iron pulleys of the same capacity.
Heavier
Lighter
Moderate
None of these
A bolt is designed on the basis of __________ with a large factor of safety.
Direct tensile stress
Direct compressive stress
Direct bending stress
Direct shear stress
The gears are termed as medium velocity gears, if their peripheral velocity is
1-3 m/s
3-15 m/s
15-30 m/s
30-50 m/s
Tapered roller bearings can take
Axial load only
Both radial and axial loads and the ratio of these being greater than unity
Radial load only
Both radial and axial loads and the ratio of these being less than unity
While designing a screw in a screw jack against buckling failure, the end conditions for the screw are taken as
Both the ends fixed
Both the ends hinged
One end fixed and the other end hinged
One end fixed and the other end free
The design of pin of a rocker arm of an I.C. engine is based on
Bearing failure
Shearing failure
Bending failure
All of these
In block brakes, the ratio of shoe width to wheel diameter is taken between
0.1 and 0.25
0.25 and 0.50
0.50 and 0.75
0.75 and 1
If two springs are in parallel then their overall stiffness will be
Half
Same
Double
None of the above
Which of the following statement is correct for gears?
The pitch circle diameter is equal to the product of module and number of teeth
The addendum is less than dedendum
The pitch circle is always greater than the base circle
All of the above
The period during which the cam follower remains at rest, when cam moves, is known as
Constant period
Fixed period
Dwell period
Idle period
The size of a cam depends upon
Base circle
Pitch circle
Prime circle
Pitch curve
The function of a washer is to
Provide cushioning effect
Provide bearing area
Absorb shocks and vibrations
Provide smooth surface in place of rough surface
In order to avoid tearing of the plate at an edge, the distance from the centre line of the rivet hole to the nearest edge of the plate should be equal to (where d = Diameter of rivet hole)
d
1.5 d
2.5 d
2 d
The contact ratio is the ratio of
Length of arc of recess to the circular pitch
Length of path of contact to the circular pitch
Length of arc of contact to the circular pitch
Length of arc of approach to the circular pitch