VALLIAMMAI ENGINEERING COLLEGE

Transcription

1 VALLIAMMAI ENGINEERING COLLEGE DEPARTMENT OF CIVIL ENGINEERING CE6603: DESIGN OF STEEL STRUCTURES QUESTION BANK UNIT I: INTRODUCTION PART-A 1. List the various types of connections used for connecting the structural members? 2. Formulate to calculate the efficiency of a joint? 3. Formulate the equation for calculating the effective throat thickness of weld? 4. List the types of failures occur in riveted joint? 5. Define riveting? 6. Define staggered pitch? 7. Differentiate nominal diameter and gross diameter of bolt. BT-2 8. List the various types of welded joints 9. Illustrate the advantages of HSFG bolts? BT Define the terms gauge, pitch, edge and end distance of bolt joint 11. Classify the types of bolts used for structural purposes? BT Recommend the four types of serviceability limit states applicable to steel structures? 13. Discuss the factors to be considered in mechanical properties of structural steel? BT Apply the assumptions made in simple design? BT Arrange the double riveted lap joint with neat sketch. BT Compare the high tension bolt from common black bolt? BT Differentiate Lap joint and Butt Joint BT Recommend about minimum pitch and maximum pitch 19. Discuss slip factor. BT Compare the advantages of welded connection over bolted connection. BT PART-B Two plates 10 mm and 20 mm thick are connected by double cover butt joint made of 8mm cover plate. Find the strength of the joint. If 6 numbers of M20 bolts of grade 4.6 and Fe 415 are used on either sides of the joint in two rows with pitch of 60mm and edge distance of 40mm in both direction. Identify the number of bolts required for a lap joint between two plates of size 100mm x 16mm and 100mm x 12mm thick so as to transmit a factored load of 120 kn using a single row of M20 bolts of grade 4.6 and grade 410 plates. 3. Discuss the types of load to be account for steel design? BT-2 4. Summarize the various limit states to be considered in design of steel structures BT-2 5. Distinguish between

2 (i) Factor of safety and partial factor for loads (ii) Characteristics loads and design loads 6. A single bolted double cover butt joint is used to connect two plates 8mmthick. 7. Assuming 20mm bolts at 50mm pitch examine the efficiency of the joint. The thickness of cover plate is4mm A load of 150 kn is applied to a bracket plate at an eccentricity of 300 mm. sixteen rivets of 20 mm nominal diameter are arranged in two rows with 8 rivets per row. The two rows are 200 mm apart and the pitch is 80 mm. if the bracket plate is 12.5 mm thick, investigate the safety of the connection. Given, s = 100 N/mm2,f b = 300 N/mm2 and f t = 150 N/mm2. 8. A tie member 75 mm X 8mm is to transmit a load of 90 kn. What is the length of the fillet weld and calculate the necessary overlap. 9. A bridge truss carries an axial pull of 400 KN. It is to be a gusset plate22mm thick by a double cover butt joint with 22 mm diameter power driven rivets. Design an economical joint. Determine the efficiency of the joint 10. Design a double riveted cover butt joint to connect 2 plates of 12mm thick. Adopt power driven rivets. Take f y = 250MPa. Find also the effieincy of the joint. BT-2 BT-3 BT-4 UNIT II: TENSION MEMBERS 1. Define tension member? 2. List the various types of tension members? 3. Define slenderness ratio. 4. When gusset plates are used? 5. Formulate to calculate net area in (a) chain bolting (b) zigzag bolting. 6. Name the types of steel sections used as tension members. 7. Classify the modes of failure in Tension member. BT-3 8. Discuss Shear Lag in Tension member? BT-2 9. Distinguish Net sectional and Gross area? BT Discuss Tension Splice BT Classify the modes of failure in Tension member. BT Illustrate built-up members? BT Explain shortly about block shear? BT Extend the equation for calculating the effective net area for a double angle joined BT-2 back to back. 15. Examine lug angle and its use? BT Investigate the design strength due to block shear. BT Plan two specifications for designing of lug angle 18. What if a single angle with one leg is connected to a gusset plate which is subjected to an eccentric load? 19. Select any two typical cross sections of tension member using angle sections with

3 neat sketch. 20. Measure the maximum pitch when the angles are placed back to back? PART-B 1. A double angle ISA 75mm x 75mm x 8mm back to back welded to one side of a 12mm gusset have allowable stress 150 MPa. identify the allowable tensile load on the members, and weld length and overlap length of gusset plate. 2. Find the safe tension of a double angle member consisting of 2 angles 90mm x 60mm x 6mm provided on either side of the gusset plate, for the following cases. 1) When tracking rivets are provided and 2) When tacking rivets are not provide Use 16mm diameter rivets 3. Discuss in detail about Tension member splice. BT-2 4. A Tension member of a roof truss carries a factored axial tension of 430KN Construct the section and its connection by the following condition (i) Without using lug angles (ii) using lug angles 5. Ilustrate lug angle with neat sketch and give its uses also. BT-3 6. Explain in detail about the modes of failure in Tension member. BT-4 7. The Main tie of a roof truss consist of ISA 150x115x8mm and its connected to a BT-2 gusset plate by 18mm diameter rivets. estimate the maximum load it carry. 8. Design a tension member to carry a factored force of 340KN. Use 20mm diameter black bolts and a gusset plate of 8mm thick. 9. Design a tension member using 2 unequal angles of size 120mmx90mmx8mm with a 10mm thick gusset plate. The short leg is outstanding. The pull on the member of 250kN. 10. Design a splice to connect a 300mmx20mm plate with 300mmx10mm plate to carry design load of 500 kn. Use 20 mm black bolts UNIT III :COMPRESSION MEMBERS 1. Define compression member? 2. List the various types of compression members? 3. Distinguish column and strut BT-2 4. List the modes of failures in a column 5. State the purpose of column base? 6. Name the types of column base? 7. Evaluate the effective length of column based on end conditions 8. Write about the forces acting on lacing system? 9. Discuss the purpose of providing battens in compound steel columns? BT Explain gusset base BT Classify the modes of failure in compression member. BT Define buckling load 13. Illustrate the lateral systems that are used in compound columns. BT-4

4 14. Explain effective sectional area in column design BT Differentiate between slab base and gusseted base for steel columns BT Examine the cause for decrease in permissible stresses due to increase in slenderness BT-4 ratio 17. Sketch the diagram of buckling modes of column. BT Justify the purpose for providing anchors bolt in base plate? 19. Where should the splice plate be located in a column? 20. Classify the columns according to the slenderness ratios. BT-3 PART B 1. A rolled steel beam section HB kn/m is used as a stanchion. If the unsupported length of the stanchion is 4 m, evaluate safe load carrying capacity of the section. 2. Design a built-up column consisting of two channels connected by batten to carry an axial load of 800 KN; the effective length of the column is 6 m. 3. Explain the step by step procedure for finding the load carrying capacity of a BT-2 compression member. 4. Describe about laced column and also explain its design and specifications. BT-2 5. Analyse the different failure modes of column in detail BT-4 6. Design a laced column for an axial load of 1200kN with an effective span of 7.5m has one end fixed and other end hinged. Use channels for main members and an angle for lacing bars. 7. A column of ISMB 400 is subjected to an axial force of 750kN. Analyse and design BT-4 suitable base plate. Assume necessary data required. 8. Illustrate in detail about column splice and mention its purpose BT-3 9. Design a rolled steel beam section column to carry an axial load 1100 KN. The column is 4 m long and adequately in position but not in direction at both ends. 10. A built up column consists ISHB 400@ kg/m with one 300mm x 12mmflange plate on each side. The column carries an axial load of 2600kN. Determine the suitable dimension for a gusseted base, if the column is supported on concrete pedestal with a bearing pressure of 5N/mm 2. UNIT IV: BEAMS 1. Define shape factor. 2. List the various factors affecting the lateral-torsional buckling strength 3. Define yield length. 4. Demonstrate the reasons behind splicing in plate girder BT-3 5. Evaluate the economical depth of a plate girder? 6. Mention the basic design assumptions of a plate girder? 7. Sketch the failure mode of laterally unsupported beams BT-3 8. Explain the behavior of steel beams BT-2 9. Explain effective sectional area in column design BT Explain the plastic method of design? BT Write a note on built up beams BT-3

5 12. Distinguish web buckling and web crippling? BT Differentiate beams, built-up beams and plate girder? BT Examine the the purpose of providing stiffener in plate girder? BT Write about the Box girders 16. Discuss the Special features of limit state design method BT Justify the purpose for providing the bearing stiffener? 18. Under what circumstances web plates are stiffened and unstiffened? 19. What is web crippling? 20. Name the components of a plate girder. PART B 1. ISMB kn/ m has been used as simply supported over a span of 4 m. The ends of beam are restrained against torsion but not against lateral bending. Evaluate the safe UDL per metre, which the beam can carry. 2. A simply supported steel joist with a 4.0m effective span carries a udl of 40kN/mover its span inclusive of self-weight. The beam is laterally unsupported. Design a suitable section. Take f y =250N/mm Explain the step by step procedure for design of vertical and horizontal stiffeners in a BT-2 plate girder. 4. Estimate the suitable built up beam section for a span of 8m to carry a uniformly BT-2 distributed load of 15kN/m and a central concentrated load of 100 kn. The beams is laterally supported through out.show the curtailment of plates also 5. Write short notes on: (i) Bending strength of a laterally supported beam (ii) Shearing strength of a laterally supported beam 6. Check the beam section WB kn/m against web crippling and web buckling if reaction at the end of beam is KN, The length of bearing plate at the support is 120 mm. Design bearing plate. The bearing plate is set in masonry 7. Ilustrate in detail the procedure for the design of Intermediate stiffeners. BT-3 8. Design a bearing stiffener for a welded plate girder with the following specifications. BT-4 Web = 1000mm X 6mm thick. Flanges = 2 Nos. of 350X20mm plate on each side. Support reaction = 350kN.Width of the support = 300mm. 9. Analyse the expression for the economical depth of the plate girder. BT A plate girder of span 15m is made-up of web plates of 1600mm x 8mm flange angles 150mmx 115mm x 10mm and two flange plates 480mm x 10mm it carries a uniformly distributed load of 100kN/m including its own weight. Design and sketch the web splices at 5m from one end. UNIT-V 1. What are the co efficient deponds on external wind pressure. BT-4 2. Compare spacing of truss and pitch of truss. BT-4 3. Types of load that may act on roof trusses? BT-3 4. Difference between beam & truss BT-2 5. Classification of deflection limits on gantry girder. BT-4

6 6. Evaluating loads on truss per sruare metre. 7. Application of gantry girder. BT-3 8. Design wind speed at Dehradun. 9. Difference between plategirder & gantry girder BT Classify the type of truss based on span. BT Define bracing. 12. Define plastic analysis 13. Define pitch of trusses 14. Calculate the plastic-moment capacity of I section. 15. Define Crane gantry girders 16. Which section is recommended for gantry girder?why 17. Define Drift Analysis 18. Explain recommended allowable stresses and deflection for gantry girder? 19. Calculate the permissible deflection for a truss of 10 m span BT Define end bearing in roof trusses? PART B A roof truss- shed is to be built Jodhpur city area for an industrial use. Determine the basic wind pressure.the use of shed 18 mx 30 m An industrial roof shed of size 20 mx30 m is proposed to be constructed at Mangalore near a hillock of 160 m and slope is 1 in 2.8. The roof shed is to be built at a height of 120 m from the base of the hill. Determine the design wind pressure on the slope. The height of roof shed shall be 12m A communications tower of 80 m height is proposed to be built hill top height 520 m with a gradient of 1in 5. The horizontal approach distance is 2.8 m km from the level ground.the tower is proposed at Abu mount.determine the design wind pressure. Design a purlin for a roof truss having the following data: Span of the truss = 6.0m,Spacing of truss = 3m c/c, Inclination of roof = 30 o Spacing of Purlin = 2m c/c Wind pressure = 1.5 kn/m 2, Roof coverage= A.C Sheeting weighing 200 N/m 2, Provide a channel section Purlin. Design a gantry girder to be used in an industrial building carrying an EOT crane for the following data: Crane capacity = 200 kn. Total self weight of all components = 240 kn. Minimum approach at the carne hook of gantry girder = 1.2m Wheel base = 3.5m C/C distance between gantry rails = 16m C/C distance between columns = 8m Self weight of rail section = 300 N/m Yield stress = 250 N/mm 2 Design the main gantry section. Connection design not required. Calculate the dead load, live load and wind load on a Fink type truss for the following data and mark the loads on the nodes of the truss. BT-3

7 Span = 12m, Pitch = ¼ of span Height at eves level = 10m from the ground Spacing of truss = 5m c/c. In an industrial building, the trusses of 16m span and 4m rise are spaced at 8m apart. The building is in medium wind zone in an industrial area of plain land. Design the purlin. Discuss briefly the following with neat sketches. i) bracing system in roof truss ii) Connection of purlin to rafter iii) Anchorages of truss with concrete column. Design a channel section purlin for the following data: Spacing of trusses =4.2m Spacing of purlin= 2m Live load on galvanized iron roofing sheets = 0.6 kn/m 2 Wind load = 1.4 kn/m 2 Slope of main rafter = 31 0 Estimate the factored forces to be considered for the design of each member MEMBER DL LL WL TOP CHORD BOTTOM CHORD MAIN SLING BT-2 BT-4