In a built up beam actual bending compressive stress fbc is given by (when y1 is the distance of the edge of the beam from the neutral axis).
fbc = (M/Ixx) × y₁
fbc = (Ixx/M) × y₁
fbc = (Ixx/M) + y₁
fbc = (M/Ixx) + y₁
Correct Answer :
A. fbc = (M/Ixx) × y₁
Related Questions
Bearing stiffener in a plate girder is used to
Transfer the load from the top flange to the bottom one
Prevent buckling of web
Decrease the effective depth of web
Prevent excessive deflection
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
When a large value of radius of gyration is not required
Channels are placed back to back
Channel flanges are kept inward
Channel flanges are kept outward
None of these
Bearing stiffeners are provided at (i) The supports (ii) The mid span (iii) The point of application of concentrated loads The correct answer is
Only (i)
Both (i) and (ii)
Both (i) and (iii)
(i), (ii) and (iii)
Effective length of a column effectively held in position and restrained in direction at both ends, is
L
0.67 L
0.85 L
1.5 L
Rolled steel beams are:
Mainly used to resist bending stress
Used as independent sections to resist compressive stress
Used as independent sections to resist tensile stress
All the above
As per IS : 875, for the purposes of specifying basic wind velocity, the country has been divided into
4 zones
5 zones
6 zones
7 zones
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)
Pick up the incorrect statement from the following:
The nominal diameter of a rivet is its diameter before driving
The gross diameter of a rivet is the diameter of rivet hole
The gross area of a rivet is the cross-sectional area of the rivet hole
The diameter of a rivet hole is equal to the nominal diameter of the rivet plus 1.5 mm
The use of tie plates in laced columns is
Prohibited
Not prohibited
Permitted at start and end of lacing system only
Permitted between two parts of the lacing
In factory buildings, the horizontal beams spanning between the wall columns supporting a wall covering, are called
Stringers
Trimmers
Girts
Lintels
Tongue plates are provided in a steel girder at
The upper flange
The lower flange
The upper end of the web
The upper and lower ends of the web
Bending compressive and tensile stresses respectively are calculated based on
Net area and gross area
Gross area and net area
Net area in both cases
Gross area in both cases
A simply supported beam carrying a central load, will be safe in deflection if the ratio of its span to depth, is
< 19
< 24
> 19
> 24
Normally, the angle of roof truss with asbestos sheets should not be less than
26 ½°
30°
35°
40°
As per ISI, rolled steel beam sections are classified into
Two series
Three series
Four series
Five series
Pick up the correct statement from the following:
Tacking rivets are used if the minimum distance between centres of two adjacent rivets exceeds 12 t or 200 mm, whichever is less
Tacking rivets are not considered to calculate stress
Tacking rivets are provided throughout the length of a compression member composed of two components back to back
All the above
Rolled steel Tee-sections are used
As columns
With flat strips to connect plates in steel rectangular tanks
As built up sections to resist axial tension
None of these
With usual notations of the letters, the shear stress fs at any point of the cross-section is given by
fs =FQ/It
fs =Ft/IQ
fs =It/FQ
fs =IF/Qt
A single angle in tension is connected by one leg only. If the areas of connecting and outstanding legs are respectively a and b, net effective area of the angle, is
a - [b/{1 + 0.35 (b/a)}]
a + [b/{1 + 0.35 (b/a)}]
a - [b/{1 + 0.2 (b/a)}]
a + [b/{1 + 0.2 (b/a)}]
The effect of racking forces is considered in the design of (i) Lateral braces (ii) Chord members The correct answer is
Only (i)
Only (ii)
Both (i) and (ii)
None of the above
The diameter of a bolt hole is taken as the nominal diameter of the bolt plus
1.0 mm
1.2 mm
1.4 mm
1.6 mm
If the floor is supported at or near the bottom but top chords of a bridge is not braced, then the bridge is called
Deck type
Through type
Half through type
Double deck type
If d is the distance between the flange angles, the vertical stiffeners in plate girders without horizontal stiffeners, are spaced at a distance not less than
0.15 d
0.22 d
0.33 d
0.44 d
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
According to I.S. : 800 - 1871, lacing bars resist transverse shear equal to
1.0% of the axial load
2.0% of the axial load
2.5% of the axial load
3.0% of the axial load
The ratio of the span L of the filler joists to the depth d from the underside of the joist to the top of the structural concrete, should not exceed
60
45
35
25
Other conditions being same, the load factor in indeterminate structures is
Equal to load factor in determinate structures
More than the load factor in determinate structures
Less than the load factor in determinate structures
Unpredictable
The distance between the outer faces of flanges of a plate girder, is known as
Overall depth
Clear depth
Effective depth
None of these
In a gusseted base, when the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate
Fully by direct bearing
Fully through fastenings
50% by direct bearing and 50% through fastenings
75% by direct bearing and 25% through fastenings