Factor of safety is the ratio of
Yield stress to working stress
Tensile stress to working stress
Compressive stress to working stress
Bearing stress to working stress
Correct Answer :
A. Yield stress to working stress
Related Questions
Maximum permissible slenderness ratio of a member normally acting as a tie in a roof truss, is
180
200
250
350
For a steel grillage footing to support two unequal column loads
Line of action of the resultant of two column loads, is made to coincide with the centre of gravity of the base of the footing
Trapezoidal shape is used for the base footing
Projections of beams on either side in lower tier are such that bending moments under columns are equal
All the above
The best arrangement to provide unified behaviour in built up steel columns is by
Lacing
Battening
Tie plates
Perforated cover plates
In the cross-section of a weld, throat is the
Minimum dimension
Average dimension
Maximum dimension
None of the above
Live load
Varies in magnitude
Varies in position
Is expressed as uniformly distributed load
All the above
The main assumption of the method of simple design of steel frame work, is:
Beams are simply supported
All connections of beams, girders and trusses are virtually flexible
Members in compression are subjected to forces applied at appropriate eccentricities
All the above
The effective length of a compression member of length L, held in position and restrained in direction at both ends, is
L
0.67 L
0.85 L
1.5 L
In a truss girder of a bridge, a diagonal consists of mild steel flat 4001.S.F. and carries a pull of 80 tonnes. If the gross-diameter of the rivet is 26 mm, the number of rivets required in the splice, is
6
7
8
9
For steel members not exposed to weather, the thickness of steel should not be less than
4.5 mm
6 mm
8 mm
10 mm
Design of a riveted joint is based on the assumption:
Bending stress in rivets is accounted for
Riveted hole is assumed to be completely filled by the rivet
Stress in the plate in not uniform
Friction between plates is taken into account
The gross diameter of a rivet is the diameter of
Cold rivet before driving
Rivet after driving
Rivet hole
None of these
A structural member subjected to compressive stress in a direction parallel to its longitudinal axis, is generally known as
Column
Stanchion
Post
All the above
Stiffeners are used in a plate girder
To reduce the compressive stress
To reduce the shear stress
To take the bearing stress
To avoid bulking of web plate
The shape factor of an isosceles triangle for bending about the axis parallel to the base is:
1.5
1.7
2.0
2.34
A column splice is used to increase
Length of the column
Strength of the column
Cross-sectional area of the column
None of these
An imaginary line along which rivets are placed, is known as
Rivet line
Back line
Gauge line
All the above
If R is the reaction on the bearing plate, the minimum moment of. inertia of the bearing stiffener provided at the support of a plate girder of overall depth D, the maximum thickness of the compression flange T, carrying total load W, is
(D²/250) × (R/W)
(D3T/250) × (R/W)
(DT/250) × (R/W)
(DT/250) × (W/R)
With a percentage increase of carbon in steel, decreases its
Strength
Hardness
Brittleness
Ductility
The centrifugal force due to curvature of track is assumed to act on the bridge at a height of
1.23 m above the rail level
1.50 m above the rail level
1.83 m above the rail level
2.13 m above the rail level
The minimum thickness of plates in a steel stack should be
4 mm
5 mm
6 mm
8 mm
Poisson's ratio for steel within elastic limit, ranges from
0.15 to 0.20
0.25 to 0.24
0.25 to 0.33
0.33 to 0.35
The ratio of hydrostatic stress to the volumetric strain within the elastic range, is called
Modulus of elasticity
Shear modulus of elasticity
Bulk modulus of elasticity
All the above
The failure of a web plate takes place by yielding if the ratio of the clear depth to thickness of the web, is less than
45
55
62
82
The ratio of plastic section modulus to elastic section modulus
Is equal to 1
Is always less than 1
Is always greater than 1
Can be less than 1
Net sectional area of a tension member, is equal to its gross section area
Plus the area of the rivet holes
Divided by the area of rivet holes
Multiplied by the area of the rivet holes
None of these
If f is the maximum allowable bending stress in a tension member whose radius of gyration is r and depth is 2y, the required cross sectional area A is given by
A = My/fr²
A = My²/fr²
A = My/fr
A = My/f²r²
If P is the wind pressure in kg/cm2, v is the velocity in km/hour and K is a constant of proportionality, then
P = K/v2
v = K/P2
P = Kv2
P = Kv
To keep the intensity of bearing pressure between the column base and concrete, compressive throughout the length of the column base, the ratio of the moment M to axial load P should be
< L/3
< L/6
> L/3
> L/6
To keep the intensity of bearing pressure between the column base and concrete compressive and to vary from zero to 2P/BL, the ratio of the moment M to the axial load P should be
L/2
L/3
L/4
L/6
If d is the distance between the flange angles,
Vertical stiffeners are provided in steel plate girders if the web is less than d/85
Vertical stiffeners are provided in high tensile steel plate girders if the web is less than d/175
Horizontal stiffeners are provided in steel plate girders if the web is less than d/200
All the above