Steel Structure Design Multiple Choice Questions(MCQs)& Answers
CONCEPTS & THEORIES
steel-structure-designSteel 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
Engineering Multiple Choice Questions(MCQs)& Answers
1
The maximum permissible slenderness ratio of compression member carrying dead and superimposed load, is
Answer: 180
2
The maximum axial load which is just sufficient to keep a column in a small deflected shape, is called
Answer: 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
Answer: In the elastic range
4
The slenderness ratio of a column is zero when its length
Answer: Is between the points of zero moments
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
Answer: Staggered pitch
8
A structural member subjected to compressive stress in a direction parallel to its longitudinal axis, is generally known as
Answer: 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
Answer: 2.0 mm thickness of packing
13
The allowable stress in axial tension for rolled I-sections and channels, is taken as
Answer: 1500 kg/cm2
14
The ratio of longitudinal stress to strain within elastic limit, is known as
Answer: Modulus of elasticity
15
Effective sectional area of a compression member is:
Answer: Gross sectional area – area of rivet hole
17
Other conditions being same, the load factor in indeterminate structures is
Answer: more than the load factor in determinate structures
18
Which of the following conditions is to be satisfied both in elastic and plastic analysis ?
Answer: equilibrium condition
20
Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
Answer: 32 times the thickness of outside plate
21
Other conditions being same, the load factor in indeterminate structures is
Answer: more than the load factor in determinate structures
22
Which of the following conditions is to be satisfied both in elastic and plastic analysis ?
Answer: equilibrium condition
24
Tacking rivets in compression plates not exposed to the weather, have a pitch not exceeding 300 mm or
Answer: 32 times the thickness of outside plate
25
The maximum permissible slenderness ratio of compression member carrying dead and superimposed load, is
Answer: 180
26
The maximum axial load which is just sufficient to keep a column in a small deflected shape, is called
Answer: 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
Answer: In the elastic range
28
The slenderness ratio of a column is zero when its length
Answer: Is between the points of zero moments
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
Answer: Staggered pitch
32
A structural member subjected to compressive stress in a direction parallel to its longitudinal axis, is generally known as
Answer: 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
Answer: 2.0 mm thickness of packing
37
The allowable stress in axial tension for rolled I-sections and channels, is taken as
Answer: 1500 kg/cm2
38
The ratio of longitudinal stress to strain within elastic limit, is known as
Answer: Modulus of elasticity
39
Effective sectional area of a compression member is:
Answer: Gross sectional area – area of rivet hole
41
According to IS Specifications, the maximum pitch of rivets in compression is
Answer: lesser of 200 mm and 12 t
47
When the bolts are subjected to reversal of stresses, the most suitable type of bolt is
Answer: high strength bolt
50
Select the correct statement
Answer: Bolts are used as a temporary fastenings whereas rivets are used as permanent fastenings.
52
By providing sufficient edge distance, which of the following failures of riveted joint can be avoided ?
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
Answer: 24 mm
55
The difference between gross diameter and nominal diameter for the rivets up to 25 mm diameter is
Answer: 1.5 mm
56
Which of the following types of riveted joint is free from bending stresses ?
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
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
Answer: only shear stresses
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
Answer: 50% by direct bearing and 50% through fastenings
60
Bending compressive and tensile stresses respectively are calculated based on
Answer: gross area and net area