St.MARTIN’S ENGINEERING COLLEGE Dhulapally, Secunderabad-500 014

Subject: STEEL STRUCTURES DESIGN AND DRAWING CIVIL: III/II

PART – A (SHORT ANSWER QUESTIONS)

UNIT-I Materials - Making of iron and steel - types of structural steel - mechanical properties of steel - concepts of plasticity - yield strength. Loads- and combinations loading wind loads on roof trusses, behavior of steel, local buckling. Concept of limit state design – Different limits states as per IS 800-2007- Design strengths - deflection limits – serviceability – Bolted connections – Welded connections – Design Strength – Efficiency of joint – Prying action types of welded joints – Design of Tension members – Design strength of members.

1 What are the factors that will govern the structural design?

2 Which type of steel is most commonly used in general construction? Why?

3 State the physical and mechanical properties of steel as a structural material.

4 What are the structural elements of a building?

5 What are the various types of structural steel sections?

Or How would you classify the various types of structural steel sections.

6 Explain briefly the wind load to be considered in the design of steel

structures.

7 Mention the advantages and disadvantages of steel structures.

8 What are the load combinations for the design purposes?

9 How the rolled steel beams are classified?

10 Draw the stress strain curve for mild steel

11 Name different types of connections used for connecting structural members?

14 Define bolts?

15 Define Fillet weld and Butt weld?

16 Define Factor of Safety

17 Write down the equation for calculating the effective throat thickness of a weld?

18 Define pitch of the bolting.

19 What are black bolts? Where are they used?

20 Demonstrate the advantages and disadvantages of welded connections?

21 Summarize some of the requirements of a good connection or good joint

22 Define Tension members.

23 What are the types of tension members?

24 What is net section area?

25 Write short notes on lug angles.

26 How is net effective area of a single angle used as tension

27 How is net effective area of a double angle used as tension member calculated?

28 How is the net sectional area calculated in case of (i) chain riveting (ii) zig zag rivetting

29 How the tension members are classified?

30 What is meant by Tension splice?

31 What is the permissible stress in axial tension?

UNIT – II

Design of compression members - buckling class, slenderness ratio / strength design - laced, - battened columns, column spice - column base, slab base.

1 Define: Compression member

2 State four standard conditions of support conditions of compression members and state corresponding expressions for

3 Name the modes of failure in a column.

4 Define Slenderness ratio. Classify the columns according to the slenderness ratios.

5 State the assumptions that made in Euler’s theory

6 Why the lateral systems are provided in compound columns?

7 Name the lateral systems that are used in compound columns and which is the mostly used one?

8 Name the types of column base and state the purpose of column base.

9 Give the difference slab base and gusseted base for steel columns.

10 When the slenderness ratio of compression member increases,

the permissible stress decreases. Why?

UNIT - III

Design of Beams - Plastic moment - Bending and shear strength laterally / supported beams design - Built-up sections – large plates Web buckling Crippling and Deflection of beams, Design of Purlin

1 Define: Beam

2 What do you mean by Castellated beam?

3 How the beams are failed?

4 What is the maximum deflection that to be allowed in steel beams?

5 What is web crippling?

6 What are laterally supported beams?

7 Write the advantages of using rolled steel wide flange section as beams

8 Write short notes on the permissible stresses used in beams?

9 Differentiate between the bending and buckling of a beam.

10 Why should plastic or compact section be preferred for flexural members in

limit state design method?

11 Write notes on built up section. Under what circumstances you would go for Built-up members?

UNIT – IV

Design of eccentric connections with brackets, beam end connections – Web angle – Unstiffened and stiffened seated connections ( bolted and Welded types) Design of truss joints

1 What are eccentric riveted connections?

2 What is meant by Framed connections?

3 When the seated beam connections are preferred and name the

4 What is stiffened seat connection?

5 Write down the interaction equation?

6 What is bracket connection?

7 How is the building connections classified based on their

moment-rotation characteristics?

8 Draw the sketch of bolted bracket connections

9 Give some examples of light moment connections.

10 What are shear connections and moment connections?

UNIT - V

Design of welded plate Girders, optimum depth, design of main section - Design of end bearing stiffness bearing and intermediate stiffeness. Connection between web and flange and Design of flange splice and web splices

1 Name the components of a plate girder.

2 Where is the plate girder used?

3 What is the expression for the economical depth of a plate

girder?

4 Mention the basic design assumptions of a plate girder.

5 Why intermediate stiffeners are required for plate girders?

6 What is gantry girder and what are the forces that are acting on

7 Differentiate between surge load and drag load as applied to

gantry girders carrying cranes.

8 What is drag force?

9 Sketch the various forms of gantry girders.

10 What is the purpose of providing the bearing stiffener?

PART – B (LONG ANSWER QUESTIONS)

UNIT – I: Materials - Making of iron and steel - types of structural steel - mechanical properties of steel -concepts of plasticity - yield strength. Loads- and combinations loading wind loads on roof trusses, behavior of steel, local buckling. Concept of limit state design – Different limits states as per IS 800-2007- Design strengths - deflection limits – serviceability – Bolted connections – Welded connections – Design Strength – Efficiency of joint – Prying action types of welded joints – Design of Tension members – Design strength of members.

1 Explain about the loads to be considered in the Limit State design of

steel structures.

2 Briefly explain the possible limit states that are considered in the limit

state method of design of steel structures.

3 Write short notes on general stability, stability against overturning and

sway stability.

4 What are the various steps involved in the construction of steel

5 Briefly explain the various stability checks considered by the IS code.

6 Classify the steel structural members based on the load transfer.

7 Explain the concepts of “plasticity” and “yield strength”

8 Explain the concept of limit state design and limit states.

9 Explain the concept of design strength and deflection limits

10 Write a short note on serviceability and stability check.

11 Design a connection to join two plates of size 250 x 12 mm of grade

Fe410, to mobilize full plate tensile strength using shop fillet welds, if

(a) a lap joint is used (b) a double cover butt joint is used.

12. Discuss the advantages and disadvantages of riveted connection and

bolted connection.

13. Two plates of a boiler 10 mm thick are connected by M16 bolts of grade

4.6 at a spacing of 50 mm. If it is lap joint, determine the efficiency of

the connection.

14. Sketch the various patterns of riveted joints

15. Calculate the strength of a 20 mm diameter bolt of grade 4.6 for the

following cases. The main plates to be joined are 12 mm thick

17. A 300 ISF 14 mm of grade Fe410 is used as a tension member in a Application

lattice girder. It is connected to a 18 mm thick gusset plate by 18 mm

diameter bolts of grade 4.6 Calculate the effective net area of the

member, if

(a) Chain bolting is done as shown in Figure 1.

(b) Zig-zag bolting is done as shown in Figure 1.

18. Two Flats of Fe 410 grade steel, each 210 mm x 8mm, are to be jointed Synthesis

using 20 mm diameter, 4.6 grade bolts, to form a lap joint. The joint has

to transfer a factored load of 275 kN. Design the joint and determine

suitable pitch for the bolts.

16.An I-section bracket is connected to the column by welds as shown in

Figure. Determine the load W which can be safely carried. The

permissible stress in the weld is 110N/m2. The size of the weld is 10mm.

300 mm

W 165 mm

20o

mm

400 mm

25

0

19. Two plates 10 mm and 18 mm thick are to be joined by double cover

butt joint. Design the joint for the following data,

Factored design load = 650 kN

Bolt diameter = 20 mm

Grade of Steel = Fe 410

Grade of bolts = 4.6

2 cover plates (one on each side) = 8 mm thick.

20. Explain how the design strength of a tension member is determined

subjected to axial tension.

21 Write the procedure for the design of tension member subjected to both

bending and axial tension.

22 Design a splice to connect 300 x 200 mm plate with a 300 x 10 mm

plate. The design load is 450 kN and the bolts are 20 mm black bolts

fabricated in the shop.

23 What are the applications of tension members? Give some examples.

24 Compute the tensile strength of an angle section ISA 150 x 115 x 12 mm

of Fe 410 grade steel connected with the gusset plate as shown in the

figure below for the following cases.

(i) Gusset section yielding

(ii) Net section rupture

140 mm

115 mm

150

mm

60 mm

(a)

(b)

25 Design a tie member of a roof truss to carry a load of 75 kN using a

single angle. Length of the member between the nodal points is 1.2

meters. Design a suitable weld to connect the member to a gusset plate 6

mm thick.

26 Explain the different modes of failure of tension member?

27 What are the factors that influence the strength of tension members?

28 A single unequal angle 100 x 75 x 6 is connected to a 10-mm thick

gusset plate at the ends with six 16mm diameter bolts to transfer tension

as shown in Figure below. Determine the design tensile strength of the

angle assuming that the yield and the ultimate stress of steel used are 250

Mpa and 410 Mpa. If the gusset is connected to the 100-mm leg. [5

Marks]

10 mm 40

5 x40 40

ISA 100 X 75 X 6

T A = 1010 mm2

g

16 mm bolt

UNIT – II Design of compress in members - buckling class, slenderness ratio / strength design - laced, - battened columns, column spice - column base, slab base.

1 Design a built-up column of two channels placed toe to toe. The

effective length of the columns is 5m. The column carries an axial load

of 2000 kN. Also design the lacing system.

2 Design of a gusseted base for a column ISWB 450, 5.5 m long with

cover plates of 400 mm x 20 mm on both faces. The column carries a

factored load of 4000 kN. M10 plain concrete will be provided under the

base plate. Sketch the column base neatly.

3 Write short notes on,

(a) Buckling class of cross-section (b) Slenderness ratio

4 Explain the step by step procedure for finding the load carrying capacity

of a compression member.

5 Design a compression member of two channels placed toe-to-toe. The

length of the compression member is 8 m and carries a load of 1000

kN.The width over the backs of channels is 450 mm. the channels are

connected by battens, sketch the c/s of the column.

6 Write short notes on laced column and also explain its design and

specifications.

7 Design a rolled steel section which is effectively held in position but not in direction at the ends and carries an axial load of 1600 kN and an axial moment of 30 kNm. Sketch the cross-section of the column.

8 Design a built up column composed of two channel sections placed back

to back, carrying on axial load 1000 kN. The effective length of the

column is 6 m. Also design a single lacing system.

UNIT - III Design of Beams - Plastic moment - Bending and shear strength laterally / supported beams design - Built-up sections – large plates Web buckling Crippling and Deflection of beams, Design of Purlin

1 Design a simply supported plated rolled steel beam section to carry a

uniformly distributed load of 50 kN/m inclusive of self weight. Effective

span of the beam is 6 m. The depth of the beam is not to exceed 450

mm. The compression flange of the beam is laterally supported.

2 Explain plastic moment carrying capacity of a section

3 What are laterally supported beams? Explain the design procedure for

laterally supported beam.

4. Write short notes on:

(i) Bending strength of a laterally supported beam

(ii) Shearing strength of a laterally supported beam

5 Write short notes on Built-up beams and also explain the procedure for

the design of built-up beams.

6 Write short notes on web crippling and web buckling

7 A beam, consisting of ISMB 600@ 122.6 kg/m is simply supported over

a span of 8.5 m. Determine the safe load the beam can carry, assuming

that the beam is laterally supported. Take fy = 250 N/mm2, E = 2 x 105

N/mm2

8 A roof of a hall measuring 8 m x 12 m consists of 100 mm thick R.C.

slab supported on steel I- beam spaced 3m apart as shown in Figure. The

finishing load may be taken as 1.5kN/m2 and live load as 1.5 kN/m2,

Design the steel beam.

9 Design a simply supported plated rolled steel beam section to carry a

uniformly distributed load of 40 kN/m inclusive of self weight. Effective

span of the beam is 5 m. The depth of the beam is not to exceed 450

mm. The compression flange of the beam is laterally supported.

10 Explain plastic moment carrying capacity of a section?

UNIT – IV

Design of eccentric connections with brackets, beam end connections – Web angle – Unstiffened and stiffened seated connections ( bolted and Welded types) Design of truss joints

1. Determine the safe load P that can be carried by the joint shown in

Figure. The bolts used are 20 mm diameter of grade 4.6. The thickness

of the Flange of I-section is 9.1 mm and that of bracket plate 10 mm.[ 5

Marks]

P F1 200 mm

F2

θ

40 mm A

A

rn 160 mm 80mm

θ

80mm

80mm 60 mm 80mm

40mm A (b)

120 mm

(a)

2. Design a bracket connection to transfer an end reaction of 225 kN due to

factored loads as in Figure below. The end reaction from the girder acts

at an eccentricity of 300 mm from the face of the column flange. Design

bolted joint connecting the Tee-flange with the column flange. Steel is of

grade Fe 410 and bolts of grade 4.6. [ 5 Marks]

A 225 kN

300 mm

Tee bracket

A

3. An ISLB 300 @ 369.8 N/m transmits an end reaction of 385 kN, under

factored loads, to the web of ISMB 450 @710.2 N/m. Design a bolted

framed connection. Steel is of grade Fe410 and bolts are of grade 4.6. [5

Marks]

4. Design a stiffened seat connection for an ISMB 350@ 514 N/m

transmitting an end reaction of 320 kN (due to factored loads) to a

column section ISHB 300 @ 576.8 N/m. The steel is of grade Fe 410

and bolts of grade 4.6. [5 Marks]

5. Explain the design of framed connections using bolts.

6. Explain the design of framed beam connection.

7. Explain the design of angle framed connection.

8. Explain the design of double plated framed connection.

9. Explain the various steps involved in the design of stiffened seat

connection

10. Design a bracket connection to support an end reaction of 200 kN. The

eccentricity of the load is 250 mm as shown in Figure.

200 kN

250 mm

60 mm

60 mm

60 mm 200

60 mm ISHB

150

60 mm 250 mm

90 mm

UNIT - V Design of welded plate Girders, optimum depth, design of main section - Design of end bearing stiffness bearing and intermediate stiffness. Connection between web and flange and Design of flange splice and web splices

1. Explain the procedure for the design of plate girders.

2. Derive the expression for the economical depth of the plate girder.

Assume moment is resisted by flanges only.

3. Explain the procedure for the design of connection between flange and

web plates.

4. Explain the procedure for the design of bearing stiffeners.

5. Explain the procedure for the design of Intermediate stiffeners.

6. Design a welded plate girder 24 m in span and laterally restrained

throughout. It has to support a uniform load of 100 kN/m throughout the

span exclusive of self-weight. Design the girder without intermediate

transverse stiffners. The steel for the flange and web plates is of grade Fe

410. Yield stress of steel may be assumed to be 250 MPa irrespective of

the thickness of plates used. Design the cross section, the end load

bearing stiffner and connections. [ 5 Marks] [ Page No. 627, S.K.

Duggal 2nd edition]

7. Design a gantry girder to be used in an industrial building carrying a

manually operated overhead travelling crane, for the following data:

Crane capacity = 200 kN

Self weight of the crane girder excluding trolley = 200 kN

Self weight of the trolley, electric motor, hook, etc. = 40 kN

Approximate minimum approach of the crane hook to the gantry

girder = 1.20 m

Wheel base = 3.5 m

c/c distance between gantry rails =16 m

c/c distance between columns (span of gantry girder) = 8 m

Self weight of rail section = 300 N/m

Diameter of crane wheels = 150 mm

Steel is of grade Fe 410. Design also the field welded connection if

required. The support bracket connection need not be designed. [5

marks]

8. Design a welded plate girder spanning 25 m and supporting a uniformly distributed load of 150 kN/m and two concentrated loads of 300 kN at third points. Also design the stiffeners. Draw to scale,

(a) Cross-section of plate girder

(b) Longitudinal elevation of plate girder [5 Marks]

9. A welded plate girder is made up of 2500 x 12 mm web plate, flange

plate of 500 x 50 mm. The girder has a span of 40 meters. It carries a

load of 50kN/m inclusive self weight over the span. Design the

Intermediate stiffener.

10. Design the plate girder of span 24 m to carry on superimposed load of

35kN/m. Avoid use of Intermediate stiffeners and bearing stiffeners. Use

Fe 415(ε 250) steel.

PREVIOUS QUESTIONS

June 2014 1. Design a laterally unsupported beam for the following data Effective span = 5 m Maximum Bending Moment = 400kNm Maximum Shear Force = 100 kN

Steel of grade Fe410.

June 2013 2. Design a simply supported plated rolled steel beam section to carry a uniformly distributed load of 50 kN/m inclusive of self weight. Effective span of the beam is 6 m. The depth of the beam is not to exceed 450 mm. The compression flange of the beam is laterally supported.

3. May 2012 Set 1: A hall 8m x 24m is covered with an RC slab 150 mm thick supported on rolled

steel beams spaced at 4meters apart. If the live load is 3 kN/m2 design the beam as per IS

800. Walls around are 300 mm thick.

4. May 2012 Set 2: Design an unstrained beam of 7 m span subjected to service loads as follows. Dead load 75 kN/m and imposed load of 25 kN/m.

5. May 2012 Set3: Design a steel rolled steel joist for a roof of a hall 7.5 m x 12m consists of 100 mm thick RC slab supported on steel beams spaced at 3m apart. The finishing may be

taken as 1kN/m2 and the live load is taken as 4 kN/m

2. Self weight of the beams is taken as

1kN/m. Take the limiting deflection as span/250.

6. May 2012 set4: Design a 20m long simply supported welded plate girder carrying a uniformly distributed load of 60 kN/m excluding the self-weight and three concentrated loads of 350 kN each at quarter span. Assume the girder is laterally supported through out.

7. May 2012 set4: A compound beam is to carry a uniformly distributed dead load of 300 kN and an imposed load of 500 kN. The beam is simply supported over a span of 12 meters. Allow 30kN for the weight of the beam. The overall depth should not exceed 700 mm the bearing plate width is 300 mm. Full lateral support is provided for compression flange.