Steel Structure Design Multiple Choice Questions(MCQs) & Answers

Steel Structure Design Multiple Choice Questions(MCQs)& Answers Steel Structure Design

CONCEPTS & THEORIES

steel-structure-design

Steel design or structural steel design is an area of structural engineering used to design steel structures. These structures include schools, houses, bridges, commercial centers, tall buildings, warehouses, aircraft, ships and stadiums. The design and use of steel frames are commonly employed in the design of steel structures. More advanced structures include steel plates and shells.

A steel structure is composed of structural members that are made of steel, usually with standard cross-sectional profiles and standards of chemical composition and mechanical properties. The depth of steel beams used in the construction of bridges is usually governed by the maximum moment, and the cross section is then verified for shear strength near supports and lateral torsional buckling (by determining the distance between transverse members connecting adjacent beams). Steel column members must be verified as adequate to prevent buckling after axial and moment requirements are met.

Methods of Steel Structure Design

1. Simple Design of Steel Structure
Simple design is the most traditional approach and is still commonly used. It is assumed that no moment is transferred from one connected member to another, except for the nominal moments which arise as a result of eccentricity at joints.
2. Continuous Design of Steel Structure
In continuous design, it is assumed that joints are rigid and transfer moment between members. The stability of the frame against sway is by frame action. Continuous design is more complex than simple design therefore software is commonly used to analyse the frame.
3. Semi-Continuous Design of Steel Structure
True semi-continuous design is more complex than either simple or continuous design as the real joint response is more realistically represented. Analytical routines to follow the true connection behaviour closely are highly involved and unsuitable for routine design, as they require the use of sophisticated computer programs.

Main structural types

Frame structures: Beams and columns
Grids structures: latticed structure or dome
Prestressed structures
Truss structures: Bar or truss members
Arch structure
Arch bridge
Beam bridge
Cable-stayed bridge
Suspension bridge
Truss bridge: truss members

Why steel structure is the best choice?

1. Cost savings
Steel structure is the cost leader for most projects in materials and design. It is inexpensive to manufacture and erection, requires less maintenance than other traditional building methods.
2. Creativity
Steel has a natural beauty that most architects can’t wait to take advantage of. Steel allows for long column-free spans and you can have a lot of natural light if you want it in any shape of structures.
3. Control and Management
Steel structures is fabricated at factory and rapidly erected at construction site by skilled personnel that makes safe construction process. Industry surveys consistently demonstrate that steel structures is the optimal solution in management.
4. Durability
It can withstand extreme forces or harsh weather conditions, such as strong winds, earthquakes, hurricanes and heavy snow. They are also unreceptive to rust and, unlike wood frames, they are not affected by termites, bugs, mildew, mold and fungi.

QUESTIONS

1 The maximum permissible slenderness ratio of compression member carrying dead and superimposed load, is
A 180
B 350
C 200
D 250

2 The maximum axial load which is just sufficient to keep a column in a small deflected shape, is called
D All the above

3 A 20 mm dia steel bar which is subjected to an axial tension of 2300 kg/cm2 produces a strain of 0.04 cm. If Young’s modulus of steel is 2.1 × 106 kg/cm2, the bar is
A In the elastic range
B In the plastic range
C At yield point
D None of these

4 The slenderness ratio of a column is zero when its length
A Is between the points of zero moments
B Is supported on all sides throughout its length
C Is equal to its radius of gyration
D Is zero

Answer: Is between the points of zero moments
5 The permissible bearing stress in steel, is
A 1890 kg/cm2
B 2025 kg/cm2
C 1500 kg/cm2
D 2340 kg/cm2

6 The distance measured along one rivet line from the centre of a rivet to the centre of adjoining rivet on an adjacent parallel rivet line, is called
A Staggered pitch
B Gauge distance of rivet
C Pitch of rivet
D All the above

7 The average shear stress for rolled steel beam section, is
A 845 kg/cm2
B 945 kg/cm2
C 1025 kg/cm2
D 1500 kg/cm2

8 A structural member subjected to compressive stress in a direction parallel to its longitudinal axis, is generally known as
A Post
B Stanchion
C Column
D All the above

9 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
A 1.00 mm thickness of packing
B 1.50 mm thickness of packing
C 2.0 mm thickness of packing
D 2.50 mm thickness of packing

Answer: 2.0 mm thickness of packing
10 A riveted joint may experience
A Bearing failure
B Shear failure of plates
C Shear failure
D All the above

11 The main advantage of a steel member, is:
A Its long service life
B Its gas and water tightness
C Its high strength
D All the above

12 A compression member consisting of angle sections may be a
A Discontinuous double angle strut
B Discontinuous single angle strut
C Continuous member
D All the above

13 The allowable stress in axial tension for rolled I-sections and channels, is taken as
A 1500 kg/cm2
B 2125 kg/cm2
C 1420 kg/cm2
D 1810 kg/cm2

14 The ratio of longitudinal stress to strain within elastic limit, is known as
A Bulk modulus of elasticity
B Modulus of elasticity
C Shear modulus of elasticity
D All the above

15 Effective sectional area of a compression member is:
A Gross sectional area + area of rivet hole
B Gross sectional area – area of rivet hole
C Gross sectional area + area of rivet hole
D Gross sectional area × area of rivet hole

Answer: Gross sectional area – area of rivet hole
16 Diameter of a bolt hole is usually taken as
A Gross diameter of bolt
B Nominal diameter + 1.5 mm
C Nominal diameter + 2.0 mm
D Nominal diameter of bolt

Answer: Nominal diameter + 1.5 mm
17 Other conditions being same, the load factor in indeterminate structures is
A equal to load factor in determinate structures
B more than the load factor in determinate structures
C less than the load factor in determinate structures
D unpredictable

18 Which of the following conditions is to be satisfied both in elastic and plastic analysis ?
A plastic moment condition
B equilibrium condition
C yield condition
D mechanism condition

19 The most economical section for a column, is
A rectangular
B solid round
C flat strip
D tubular section

20 Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
A 16 times the thickness of outside plate
B 24 times the thickness of outside plate
C 32 times the thickness of outside plate
D 36 times the thickness of outside plate

Answer: 32 times the thickness of outside plate
21 Other conditions being same, the load factor in indeterminate structures is
A equal to load factor in determinate structures
B more than the load factor in determinate structures
C less than the load factor in determinate structures
D unpredictable

22 Which of the following conditions is to be satisfied both in elastic and plastic analysis ?
A plastic moment condition
B equilibrium condition
C yield condition
D mechanism condition

23 The most economical section for a column, is
A rectangular
B solid round
C flat strip
D tubular section

24 Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
A 16 times the thickness of outside plate
B 24 times the thickness of outside plate
C 32 times the thickness of outside plate
D 36 times the thickness of outside plate

Answer: 32 times the thickness of outside plate
25 The maximum permissible slenderness ratio of compression member carrying dead and superimposed load, is
A 180
B 350
C 200
D 250

26 The maximum axial load which is just sufficient to keep a column in a small deflected shape, is called
D All the above

27 A 20 mm dia steel bar which is subjected to an axial tension of 2300 kg/cm2 produces a strain of 0.04 cm. If Young’s modulus of steel is 2.1 × 106 kg/cm2, the bar is
A In the elastic range
B In the plastic range
C At yield point
D None of these

28 The slenderness ratio of a column is zero when its length
A Is between the points of zero moments
B Is supported on all sides throughout its length
C Is equal to its radius of gyration
D Is zero

Answer: Is between the points of zero moments
29 The permissible bearing stress in steel, is
A 1890 kg/cm2
B 2025 kg/cm2
C 1500 kg/cm2
D 2340 kg/cm2

30 The distance measured along one rivet line from the centre of a rivet to the centre of adjoining rivet on an adjacent parallel rivet line, is called
A Staggered pitch
B Gauge distance of rivet
C Pitch of rivet
D All the above

31 The average shear stress for rolled steel beam section, is
A 845 kg/cm2
B 945 kg/cm2
C 1025 kg/cm2
D 1500 kg/cm2

32 A structural member subjected to compressive stress in a direction parallel to its longitudinal axis, is generally known as
A Post
B Stanchion
C Column
D All the above

33 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
A 1.00 mm thickness of packing
B 1.50 mm thickness of packing
C 2.0 mm thickness of packing
D 2.50 mm thickness of packing

Answer: 2.0 mm thickness of packing
34 A riveted joint may experience
A Bearing failure
B Shear failure of plates
C Shear failure
D All the above

35 The main advantage of a steel member, is:
A Its long service life
B Its gas and water tightness
C Its high strength
D All the above

36 A compression member consisting of angle sections may be a
A Discontinuous double angle strut
B Discontinuous single angle strut
C Continuous member
D All the above

37 The allowable stress in axial tension for rolled I-sections and channels, is taken as
A 1500 kg/cm2
B 2125 kg/cm2
C 1420 kg/cm2
D 1810 kg/cm2

38 The ratio of longitudinal stress to strain within elastic limit, is known as
A Bulk modulus of elasticity
B Modulus of elasticity
C Shear modulus of elasticity
D All the above

39 Effective sectional area of a compression member is:
A Gross sectional area + area of rivet hole
B Gross sectional area – area of rivet hole
C Gross sectional area + area of rivet hole
D Gross sectional area × area of rivet hole

Answer: Gross sectional area – area of rivet hole
40 Diameter of a bolt hole is usually taken as
A Gross diameter of bolt
B Nominal diameter + 1.5 mm
C Nominal diameter + 2.0 mm
D Nominal diameter of bolt

Answer: Nominal diameter + 1.5 mm
41 According to IS Specifications, the maximum pitch of rivets in compression is
A lesser of 200 mm and 12 t
B lesser of 200 mm and 161
C lesser of 300 mm and 32 t
D lesser of 3 00 mm and 24 t

Answer: lesser of 200 mm and 12 t
42 The actual thickness of butt weld as compared to the thickness of plate is usually
A more
B equal
C less
D none of the above

43 A butt weld is specified by
A effective throat thickness
B plate thickness
C size of weld
D penetration thickness

44 For a standard 45° fillet, the ratio of size of fillet to throat thickness is
A 1:1
B 1 : V2
C V2 : 1
D None

45 The effective length of a fillet weld should not be less than
A two times the weld size
B four times the weld size
C six times the weld size
D weld size

Answer: four times the weld size
46 In the cross-section of a weld, throat is the
A minimum dimension
B average dimension
C maximum dimension
D none of the above

47 When the bolts are subjected to reversal of stresses, the most suitable type of bolt is
A high strength bolt
B turned and fitted bolt
C black bolt
D ordinary unfinished bolt

48 Diameter of a bolt hole is usually taken as
A nominal diameter + 1.5 mm
B gross diameter of bolt
C nominal diameter + 2.0 mm
D nominal diameter of bolt

Answer: nominal diameter + 1.5 mm
49 Bolts are most suitable to carry
A axial tension
B shear and bending
C bending
D shear

50 Select the correct statement
A Material cost of a rivet is higher than that of a bolt.
B Tensile strength of a bolt is lesser than that of a rivet.
C Bolts are used as a temporary fastenings whereas rivets are used as permanent fastenings.
D Riveting is less noisy than bolting.

Answer: Bolts are used as a temporary fastenings whereas rivets are used as permanent fastenings.
51 Efficiency of a riveted joint, having the minimum pitch as per IS : 800, is
A 40%
B 50%
C 60%
D 70%

52 By providing sufficient edge distance, which of the following failures of riveted joint can be avoided ?
A tension failure of the plate
B shear failure of the rivet
C shear failure of the plate
D crushing failure of the rivet

Answer: shear failure of the plate
53 If the thickness of plate to be connected by a rivet is 16 mm, then suitable size of rivet as per Unwin’s formula will be
A 16 mm
B 20 mm
C 24 mm
D 27 mm

54 As compared to field rivets, the shop rivets are
A stronger
B equally strong
C weaker
D any of the above

55 The difference between gross diameter and nominal diameter for the rivets up to 25 mm diameter is
A 1.0 mm
B 1.5 mm
C 2.5 mm
D None

56 Which of the following types of riveted joint is free from bending stresses ?
A lap joint
B butt joint with single cover plate
C butt joint with double cover plates
D none of the above

Answer: butt joint with double cover plates
57 When the axis of load lies in the plane of rivet group, then the most heavily loaded rivet will be the one which
A gives the minimum angle between the two forces Fa and Fm
B gives the maximum angle between the two forces Fa and Fm
C is at the minimum distance from CG of the rivet group
D is at the maximum distance from CG of the rivet group

Answer: gives the minimum angle between the two forces Fa and Fm
58 When the axis of load lies in the plane of rivet group, then the rivets are subjected to
A only shear stresses
B only tensile stresses
C both (a) and (b)
D none of the above

59 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
A fully by direct bearing
B fully through fastenings
C 50% by direct bearing and 50% through fastenings
D 75% by direct bearing and 25% through fastenings

Answer: 50% by direct bearing and 50% through fastenings
60 Bending compressive and tensile stresses respectively are calculated based on
A net area and gross area
B gross area and net area
C net area in both cases
D gross area in both cases

Answer: gross area and net area