2160607- elementary structural design tutorial-1...

B.E. 6th Sem. Civil Engineering, Applied Mechanics Department, SSEC-BHAVNAGAR

Tutorial-1: Philosophy of Limit state design-2018

2160607- Elementary Structural Design

Tutorial-1: Philosophy of Limit state design

Q.1 Explain the principles of (a) Working stress method of design (b) Ultimate load

design (c) Limit state Design

Q.2. Explain how limit state method differs from working stress method of design

Q.3. Explain how limit state method differs from ultimate load method of design

Q.4. Explain following terms (a) Partial safety factor for loads (b) Partial safety factor for

material strength

Q.5. Distinguish between Factor of safety and partial safety factor

Q.6 Characteristic loads and design (factored) loads.

Q.7. Explain advantages and disadvantages of using steel structures.

Q.8. Explain, what is structural steel? List out the important properties of such steel.

Q.9. Explain the special considerations required in the design of steel structures.

Q.10 Explain briefly various types of loads to be considered in design of steel structure.

Q.11 What is the basic difference between a plastic and a compact section?

Q.12 What is the basic difference between a semi-compact and a compact section?

Q.13 Give the blt or dlt ratio for the following cases: (a) Outstand element (flange) of rolled beam of plastic section (b) Outstand element(flange)of rolled beam of semi-compact section (c) Web of an I-beam of plastic cross section (d) Web of an I-beam of semi-compact section

B.E. 6th Sem. Civil Engineering, Applied Mechanics Department, SSEC-Bhavnagar

Tutorial-2: Bolted Connections-2018 Page 1


Tutorial-2: Bolted Connections

Note-Steel of grade 410 and bolts of grade 4.6 may be used if not specified in the problem. Also,

assume that the threads of bolts fall in the plane of shear, if not specified.

Q.1 Compute the design strength of bearing-type connections based on shear and bearing for the joints shown in Fig.-1. The bolts are of grade 4.6.

Fig.-1

Q.2. A double angle section ISA 150 × 150 × 15 mm is connected to 16 mm thick gusset plate as shown in Fig. -2. Determine the service load the connection can carry on the basis of shear and bending strength. The bolts are of grade 4.6 and of 24 mm in diameter.

Fig.-2



Q.4 A double-angle tension member consists of 2 ISA 125 × 95 × 10 mm connected to a 10-mm thick gusset plate with 20 mm diameter high-strength bolts of grade 8.8, as shown in Fig.-3. Does the connection have enough capacity based on shear and bearing.

Fig.-3

Q.5 Fig.-4 shows a single angle ISA 150 × 100 × 10 mm connected to 10 mm thick gusset plate with 20 mm high-strength bolts of grade 8.8. What is the total service load that can be supported, based on shear and bearing strengths of bolts, if the bolt threads do not fall in the plane of shear?

Fig.-4

Q.6 For the connection shown in Fig.-5 determine the maximum factored load T that can be resisted. Bolts are of high strength type (grade 8.8) and of 24 mm diameter.

Fig.-5



Q.8 Determine the number of bolts, pitch and edge distance, based on shear and bearing required for making the bearing-type connection of the members shown in Fig. -6. The bolts are of grade 4.6.

Fig.-6

Q.9 Determine the total number of 24 mm diameter bearing-type bolts required for the double-bolted double-cover butt joint shown in Fig.-7. The threads of bolts may be assumed not to fall in the shear planes.

Fig.-7

Q.11 Design the connections for the members of a roof truss with a gusset plate 10 mm



thick, as shown in Fig.-8. Use 16 mm diameter bolts of grade 4.6.

Fig.-8

Q.12 Investigate the safety of the slip-critical connection shown in Fig.-9. The angle section ISA 150 × 115 × 12 mm is connected, using 30 mm diameter high-strength friction-grip bolts, to a 10 mm thick gusset plate.

Fig.-9

Q.13 For the connection of member with gusset plate shown in Fig. -10, deter-mine the number of bolts required if the slip is not permitted. The bolts used are 24 mm diameter, high strength type of grade 8.8.

Fig.-10

Q.14 Investigate the safety of the hanger connection shown in Fig. 11. Include the effect of the prying action. The bolts used are of high-strength type of grade 8.8.

Fig.-11



Q.15 Check the safety of the connection shown in Fig. 12.

Fig.-12

Q.16 Design the connection shown in Fig. 13.

Fig. 13

Q.17 Design a double-cover butt joint to connect two plates, each 12 mm thick and 300 mm wide. The service load to be transferred is 200 kN.

Q.18 Design a lap joint to connect two plates 300 mm wide and 16 mm thick using 20 mm diameter bolts of grade 4.6. The applied service load is 375 kN.

B.E. 6th Sem. Civil Engineering, Applied Mechanics Department,SSEC-BHAVNAGAR

Tutorial-3: Welded Connections-2018 Page 1


Tutorial-3: Welded Connections

Note-Use steel for grade Fe 410 and shop welding, if not specified in the problem

Q.1 Determine the strength of a 6-mm fillet weld per mm length when placed (i) in shop, (ii) at site. A 200-mm wide plate is to be jointed to another 300-mm wide plate section. Determine the design strength of the joint if the overlap of the plates is 150 mm. Both longitudinal and end fillet welds are provided. What will be the overlap required if only longitudinal fillet weds are provided? The plates are 8 mm thick and connected with minimum size of weld as per IS specification

Q.2. Determine the maximum factored load that can be applied at the joint for the cases shown in Fig.-1.

Fig.-1

Q.3 Two 12-mm thick plates are joined in the workshop by (i) a single V-butt weld, (ii) a double V-butt weld. The effective length of the weld is 220 mm. Determine the design strength of the welded joints.

Q.4 An 150 mm × 115 mm × 12 mm angle section is to be connected to a 12-mm thick gusset plate at site. Design the fillet weld to carry a load equal to the strength of the member.

Q.5 Design a fillet weld to join a tension member consisting of 2 ISA 100 mm × 75 mm × 8 mm to a 12-mm thick gusset plate. The factored tensile load is 410 kN.


Tutorial-3: Welded Connections-2018 Page 2

Q.6 Determine the service load which can be applied to the fillet welds for the cases shown in Fig.-2 Consider the weld size to be 3 mm.

Fig.-2

Q.7 A 200-mm wide and 16-mm thick plate is to be connected with an 8-mm fillet weld. Determine the length L required to develop the full strength of bar, refer Fig.-3.

Fig.-3


Tutorial-4: Design of Tension Members-2018 Page 1


Tutorial-4: Design of Tension Members

Note-Use 20-mm diameter bolt holes of grade 4.6 and steel of grade Fe 410, if not specified in

the problem. Also assume load factor = 1.5 if not specified. Assume the bolts to be in standard

clearance holes. All the dimensions are in mm.

Q.1 An ISA 100 × 75 × 10 mm is connected with a gusset plate 12 mm thick with 2-16 mm diameter bolts of grade 4.6 as shown in the Fig.-1. Determine the total net area and effective net area of the section.

Fig.-1 Q.2. An angle tie member ISA 150 × 75 × 12 mm is connected with 16 mm bolts of grade 4.6

with the connection details as shown in the Fig.-2. Determine the effective net area.

Fig.-2 Q.3 Compute the net area of the members shown in Fig.-3 below.

Fig.-3



Q.4 The tension member shown in Fig. 4 is plate 120 × 12 mm. The member is connected to a gusset plate with 20 mm diameter bolts. It is subjected to a service load of 155 kN as shown in the figure. Does this member have enough strength in net section rupture? Assume that the effective net area is equal to the net area.

Fig.-4

Q.5 A double angle tension member 2L 75 × 50 × 8 mm as show in Fig.-5 is subjected to a service load of 300 kN. It is connected to a gusset plate with one line of 16 mm diameter bolts through long legs. Does this member have enough strength? Assume that the effective net area equals to 0.80 times the net area. Neglect block shear strength.

Fig.-5

Q.6 What is the maximum factored load that can be resisted by the tension member shown in Fig.-6 below based on rupture of net section?

Fig.-6

Q.7 Design a tension member 3.4 m between c/c of intersections using double angle sections and carrying a factored pull of 200 kN. The member is subjected to reversal of stresses.



Q.8 Determine the tensile strength based on rupture of net section of the members shown in Fig.-7 .

Fig.-7

Q.9 ISMC 225 is connected with 16 mm diameter bolts as shown in Fig.-8 below. What is the maximum factored tensile load that can be resisted? Block shear strength need not be considered.

Fig.-8

Q.10 Design a tension member to carry a pull of 830 kN. The member is 3.2 m between c/c of intersections. Design the member using channel section.

Q.11 Design a tension member to carry a factored tensile load of 400 kN. Two angles placed back-to-back with long legs out-standing are desirable. The length of the member is 2.9 m.



Q.12 The 150 × 75 × 10 mm angle shown in Fig.-9 below is connected with three 20-mm bolts. Determine its block shear strength. Compare the result with the tensile design strength in net section rupture of the member.

Fig.-9

Q.13 A plate tension member is shown in Fig-10 below. It is connected to a 12 mm thick gusset plate. Determine the block shear strength of the gusset plate.

Fig.-10

Q.14 Design a tension member 3.4 m between c/c of intersections using double angle sections and carrying a factored pull of 200 kN. The member is subjected to reversal of stresses.

Q.15 A pair of unequal angles are chosen to resist a factored tensile load of 900 kN. The connection requires the arrangement shown in Fig.-11, with two gauges in its long leg and one in the short leg for 20 mm bolts. Select the most economical size of the section.

Fig.-11

Q.16 A tension member is to consist of four equal angles placed as shown in Fig.11. The section is to support a factored tensile load of 1300 kN. The member is 10 m long. The maximum side of the built-up section is restricted to 450 mm. Design the section. Provide additional plates, if required. Each angle may be assumed to have one bolt hole of 20 mm diameter in the section.

Fig.-11


Tutorial-5: Design of Compression Members-2018 Page 1


Tutorial-5: Design of Compression Members

Note-Assume steel of grade Fe 410 and bolts of grade 4.6 if not specified in the problems. Also

assume load factor = 1.5 if not specified. All the dimensions are in mm.

Q.1 A single angle section ISA 60 × 60 × 8 mm, 3.0 m long, is used as strut. The ends are welded to the gusset plates. Determine the design compressive strength and the service load that can be applied.

Q.2 A discontinuous strut of 3 m length between the intersections consists of two angles 100 × 75 × 8 mm. The angles are placed back to back on the opposite side of a 10 mm thick gusset plate with long legs connected. Calculate the percentage change in the design compressive strength if the two angles are placed on the same side of the gusset plate with short legs connected.

Q.3 A strut consists of a double angle section ISA 70 × 70 × 8 mm and is 3.2 m long. The member is connected to the gusset plate by 3, 20 mm diameter ordinary bolts. Calculate the design compressive strength of the member : (a) when the angles are placed on the opposite sides of 12 mm thick gusset plate; (b) when the angles are placed on the same side of 12 mm thick gusset plate

Q.4 The floor plan area of a multistorey building is as shown in Fig.-1. All the columns are of section ISHB 450 @ 907.43 N/m, the longitudinal beams of section ISMB 550@ 1017.30 N/m, and transverse beams of section ISMB350 @ 514.04 N/m. The storey height is 3.6 m and columns are fixed at base. For a column in a typical floor of the building determine the effective lengths kLz and kLy. For the purpose of estimating total axial load on the column in the storey assume total distributed load of 40 kN/m2 from all the floors above.

Fig.-1



Q.5 Determine the design compressive strength for the sections shown in Fig.-2.

Fig.-2

Q.6 Design a single angle discontinuous strut to carry a factored load of 150 kN. The length of the strut between c/c of intersections is 3.40 m.

Q.7 Design a double angle discontinuous strut to carry a load of 250 kN. The length of the strut between c/c of inter-sections is 3.85 m.

Q.8 Design a suitable section for compression member shown in Fig. -3

Fig.-3



Q.9 Design a built-up column with four angles laced together. The effective length of the column is 7.20 m and it supports a factored load of 1800 kN.

Q.10 Design a column with two channel sections laced together and placed toe-to-toe and spaced apart to support a factored load of 3300 kN. The effective length of column is 5.2 m.

Q.11 A column section ISHB 150 @ 265.9 N/m. is to be spliced with another column section ISHB 150 @ 339.4 N/m. The factored load on the column is 400 kN. Design the splice.

Q.12 Design a built-up column with two channels placed face-to-face. The column is of 6.6 m effective length and supports a factored load of 1500 kN. Also, design the lacing system.

Q.13 Repeat the Q.12 with design the batten system.

B.E. 6th Sem. Civil Engineering, Applied Mechanics Department

Tutorial-6: Design for Beams and Beam-Columns-2018 Page 1


Tutorial-6: Design for Beams and Beam-Columns


assume load factor = 1.5 if not specified. All the dimensions are in mm.

Q.1 Determine the elastic and plastic section modulus of the sections shown in Fig. -1.

Fig.-1

Q.2 Determine the plastic section modulii of the following sections. (a) ISMB 350@ 524 N/m. (b) ISLC 200@ 206 N/m. (c) ISLC 200@ 206 N/m, placed inverted over top flange of ISMB 350 @ 524 N/m such that the section is symmetrical about yy-axis

Q.3 Obtain shear centre for the sections shown in Fig.-2 All dimensions are in mm.

Fig.-2



Q.4 An ISLB 600 @ 976.1 N/m has been used as a simply supported beam over 7.20 m span. Determine the safe uniform load that the beam can carry in flexure. Assume Fe 410 steel. (a) The ends of the beam are restrained against torsion as well as against lateral bending. (b) The ends of the beam are restrained against torsion but not against lateral bending.

Q.5 A steel floor beam in a building has a span of 6.0 m. It is simply supported over supports and carries a uniform load of 40.0 kN/m, inclusive of self-weight. Design the beam (Fe 410 steel) if, (a) the compression flange is restrained throughout the span against lateral bending (b) the lateral supports for the compression flange are provided only at the ends

Q.6 A conference hall 8 m × 18 m is pro-vided with a 120 mm RCC slab over rolled steel beams spaced 3 m c/c. A wearing coat of 100 mm average thick-ness is provided over the roof. Design the beam section if, the compression flange of the beam is laterally supported throughout.

Q.7 A beam is to span an opening of 9 m. It carries a uniform load of 12 kN/m. The depth of the beam is limited to 450 mm from clear head room requirements. Design the cross section of the beam (Fe 410 grade steel).

Q.8 Determine the adequacy of beam-columns shown in Fig. -3, for local capacity of the section and member buckling resistance in compression and flexure. The factored forces are shown on the member.

Fig.-3



Q.9 Verify the adequacy of the beam-column section ISHB 400 @ 806.38 N/m and of effective length 3.4 m under the factored loads: P = 1500 kN, Mz = 125 kNm and My = 80 kNm for local capacity and buckling resistance of member.

Q.10 Design the beam-columns shown in Fig. -4, for the factored loads mentioned against them.

Fig.-4

Q.11 Design a beam-column of a moment resisting braced frame for the following data. Length of the column: 3.8 m Maximum axial compressive load: 1000 kN Maximum moments: at top end: Mz = 200 kNm, My = 60 kNm at bottom end: Mz = – 200 kNm, My = 50 kNm

Q.12 Design a beam-column of effective length 5.2 m carrying factored forces as below. P = 750 kN Mz, top = 80 kNm Mz, bottom = 80 kNm

Q.13 A bottom chord tension member in a roof truss is 4.0 m long. It carries a factored axial transverse load of 25 kN at its mid span along with an axial force of 450 kN. Design the tension member.


Tutorial-7: Slab base and Gusset base-2018 Page 1


Tutorial-7: Slab base and Gusset base


assume load factor = 1.5 if not specified.

Q.1 Design a suitable slab base for a column section ISHB 200 @ 365.9 N/m sup-porting an axial load of 400 kN. The base plate is to rest on a concrete pedestal of M-20 grade.

Q.2 Design the section of steel column and suitable base for an axial compressive factored force of 3000 kN. The effective length of the column is 5.2 m. The concrete used for making the pedestal is of M-30 grade.

Q.3 A column of 6.0 m effective length is carrying a factored axial compressive load of 800 kN and a factored bending moment of 75 kNm about major axis. The bearing pressure from the concrete pedestal may be assumed to be 9 N/mm2. Design a suitable base. Also design the anchor bolts, if required.

Q.4 Design a column base for a factored axial compressive load of 700 kN and a factored bending moment of 150 kN m about major axis. The column section provided is ISHB 400 @ 806.4 N/m. Design the anchor bolts also, if required. The bearing pressure from concrete may be assumed to be 6.0 kN/m2.

2160607- elementary structural design tutorial-1...

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