The allowable shear stress in the web of mild steel beams decreases with
Decrease in h/t ratio
Increase in h/t ratio
Decrease in thickness
Increase in height Where 'h' is height and t is thickness
Correct Answer :
B. Increase in h/t ratio
Related Questions
The maximum spacing of vertical stiffeners is
1.33 d
1.25 d
1.5 d
1.75 d Where d is the distance between flange angles
The equivalent axial tensile load Pe, which produces an average axial tensile stress in the section equivalent to the combined stress due to axial tension P and bending M, at the extreme fibre of the section, is given by (where Z is the section modulus of the section).
Pe = P + MA/Z
Pe = P - MA/Z
Pe = P - Z/MA
Pe = P + Z/MA
As compared to field rivets, the shop rivets are
Stronger
Weaker
Equally strong
Any of the above
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 gross diameter of a rivet is the diameter of
Cold rivet before driving
Rivet after driving
Rivet hole
None of these
The effective length of a battened strut effectively held in position at both ends but not restrained in direction is taken as
1.8 L
L
1.1 L
1.5 L
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
Modified moment of inertia of sections with a single web, is equal to moment of inertia of the section about Y-Y axis at the point of maximum bending moment and is multiplied by the ratio of
Area of compression flange at the minimum bending moment to the corresponding area at the point of maximum bending moment
Area of tension flange at the minimum bending moment of the corresponding area at the point of maximum bending moment
Total area of flanges at the maximum bending moment to the corresponding area at the point of maximum bending moment
None of these
Diameter of a rivet hole is made larger than the diameter of the rivet by
1.0 mm for rivet diameter upto 12 mm
1.5 mm for rivet diameter exceeding 25 mm
2.0 mm for rivet diameter over 25 mm
None of these
When a tension member is made of four angles with a plate as a web, the allowance for holes is made as
Two holes for each angle and one hole for the web
One hole for each angle and one hole for the web
One hole for each angle and two holes for the web
Two holes for each angle and two holes for the web
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
IS : 800 - 1971 recommends that in a splice plate the number of rivets carrying calculated shear stress through a packing greater than 6 mm thick, is to be increased by 2.5% for every
1.00 mm thickness of packing
1.50 mm thickness of packing
2.0 mm thickness of packing
2.50 mm thickness of packing
The external wind pressure acting on a roof depends on
Degree of permeability of roof
Slope of roof
Both (A) and (B)
None of the above
The thickness of the web of a mild steel plate girder is less than d/200. If only one horizontal stiffener is used, it is placed at
The neutral axis of the section
2/3rd of the depth of the neutral axis from the compression flange
2/5th of the depth of the neutral axis from the compression flange
2/5th of the height of the neutral axis from tension flange
According to IS Specifications, the maximum pitch of rivets in compression is
Lesser of 200 mm and 12 t
Lesser of 200 mm and 16 t
Lesser of 300 mm and 32 t
Lesser of 3 00 mm and 24 t Where t is thickness of thinnest outside plate or angle
The effective length of a battened column is increased by
5 %
10 %
15 %
20 %
The least permissible clear dimension of the web of thickness t in the panel of a plate girder, is restricted to
150 t
160 t
170 t
180 t
Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
16 times the thickness of outside plate
24 times the thickness of outside plate
32 times the thickness of outside plate
36 times the thickness of outside plate
For a steel member of slenderness ratio 350, the allowable stress is 76 kg/cm2 if it is
HTW grade of thickness exceeding 32 mm
HT grade of thickness exceeding 45 mm
HT grade of thickness not exceeding 45 mm
All the above
Slenderness ratio of a compression member is
Moment of inertia/Radius of gyration
Effective length/Area of cross-section
Radius of gyration/Effective length
Radius of gyration/ Area of cross-section
Number of rivets required in a joint, is
Load/Shear strength of a rivet
Load/Bearing strength of a rivet
Load/Tearing strength of a rivet
Load/Rivet value
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 overlap of batten plates with the main members in welded connections should be more than
3 t
4 t
6 t
8 t Where t = thickness of the batten plate
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
Efficiency of a riveted joint, having the minimum pitch as per IS : 800, is
40 %
50 %
60 %
70 %
Rise of a Jack arch is kept about
1/2 to 1/3 of the span
1/3 to 1/4 of the span
1/4 to 1/8 of the span
1/8 to 1/12 of the span
Load factor is
Always equal to factor of safety
Always less than factor of safety
Always greater than factor of safety
Sometimes greater than factor of safety
Effective length of a column effectively held in position and restrained in direction at one end but neither held in position nor restrained in direction at the other end, is
1.5 L
0.67 L
0.85 L
2 L
In case of timber structures, the simple bending formula M = fz may be applied for
Rectangular beams up to 300 mm depth
All rectangular beams
Solid circular beams only
All square cross-section beams
For a rectangular section, the ratio of the maximum and average shear stresses, is
1.5
2.0
2.5
3.5