; Design of Steel Structures a2 03 05 1 Sn cute atthe thickness of thinnest outside plate ig 10 mm, then the maximum pitch of rivets 9 tension will be taken as (@ 120mm (0) 160 mm (@) 200mm (@) 300 mm When the axis of load lies in the plane of rivet group, then the most heavily loaded rivet will be the one which (@) is at the CG of the rivet group (b) is at the minimum distance from CG of the rivet group (0) gives the maximum angle between the two forces F, and F., (@ gives the minimum angle between the two forces F, and F,, wihere, F, is the load shared by each rivet due to axial load and F,, is the shearing load due to moment in any rivet ‘Thedifference between gross diameter and nominal diameter for the rivets up to 25 mm diameter is (@) 1.0 mm (b) 1.5 mm (©) 20mm (6) 25 mm. lithe thickness of plate to be connected by a fivet is 16 mm, then suitable size of rivet as per Univin's formula will be @ 16mm (b) 20 mm (0) 24 mm (d) 27 mm According to IS Specifications, the maximum Pitch of rivets in compression is (@) lesser of 200 mm and 12t (0) lesser of 200 mm and 16¢ (©) lesser of 300 mm and 32t (A) lesser of 300 mm and 24¢ \where tis thickness of thinnest outside plate or angie as Q.10 u Q.6 \ Which one of the following is the mode of failure “_/ ina fillet weld material? (@) Tension (©) Bearing (0) Shear (6) Crushing a7 } Load on connection is not eccentric for \ (@) lap joint (0) single cover butt joint (©) double cover butt joint (d) all the joints mentioned in (a), (b) and (c)of the question Match List-| (Failure mode) with List-lI (Reason) and select the correct answer using the codes given below the lists: List! Shear failure of plates Bearing failure of plates Tearing failure of plates Spliting failure of plates istll 1. Insutficient edge distance 2. Strength of plates less than that ofthe rivets, Codes: A @ 1 2 @ 1 @1 gom> oo) Cc OD 2 | Ad 12 1 2 The centre to centre maximum distance between bolts in tension member of thickness 10 mm is (@) 200mm (b) 160mm (©) 120mm (6) 100mm The type of stress induced in the foundation bolts fixing a column to its footing is (@) pure compression (©) bearing (©) puretension (0) bending Scanned with CamScanner214 | Q.11} Which of he folowing doesnot describe a weld Multiple Cl ia X ‘ype? 1 @ Butt (0) Pug (©) Zig-Zag (8) Lap hen the effect of wind or earthquake load is onsidered in the design of rivets and bolts for steel structures, by what percentage the ‘ i VV" permissible stresses may be exceeded? N @) 18% (0) 25% © 33.33% (0) 50% ‘ Q.13 A 6 mm thick mild steel plate is connected 10 ‘an 8 mm thick plate by 16 mm diameter shop Fivets. What is the number of rivets required 10 ccarry an 80 kN load? @2 3 @a4 6 @y What is the permissibie tensile stress in bolts Used for column bases (fis the yield stress of ' the steely? ia (2) 120mm? A (©) or, @y ‘What is the maximum permissible longitudinal =" pitch in staggered riveted compression joints? (@) 500mm (b) 400mm + ©) 300mm (@) 100mm (©) 150.Nimm? © 04s, Q.16 What is the ratio of the yield stress in power driven shop rivets relative to the permissible bearing stress of mild steel? (@ 10 ©) 08 ~ ©) 06 (6) 04 (Q:17 Which one of the following is correct? "~The permissible stresses in a weld are usually taken as (@) less than those of the parent body (©) equal to those of the parent body (2) more than those ofthe parent body (@) any desired value Qe For field rivets, the permissible stresses are teduced by what percentage? (@) 10% (b) 18% (©) 25% @ 333% (0.19 What isthe safe load P that can be transmitted by the fillet-welded joint shown in figure below L- } 1" 1s-y d noice Questions MROE ey, | fg alowable Shear stress in MPa? if the sal weld is 108 (0) 66kN wom Bem | . | 0.20 Themaxmuniongivdeal bch alovednin, | joints of tension mert +6 times the diameter of the bolt {o) t6times the thickness of the plate (@) 2times the thickness of the plate @.21 Aboltdesignated as Hex bolt M 16x70 ya have {@) diameter of 16 mm (b) diameter of 70mm (6) length of 16mm (@) cross-sectional area of 16 x 70 om? 0.22 A structural member carrying @ pull of 7044. | is connected to a gusset plate using rivets | 20mmdiameter. Ifthe pullrequiredforsheaing | the rivets, to crush the rivets and to tear the plate per pitch length are 60 KN, 35 kN arg | 70 KN respectively, then the number of rivels required is | (@) 12 (b) 18 f () a (d) 22 group, then the rivets are subjected to (@) Shear only (©) Tension only (¢) Bending only ~,"(0) Both shear and bending | | Q.23, When load line coincides with the C.G. of ret \ | | Q.24 For ‘reversal of stresses the ‘most suitable bolts | @) Black bot (&) Turned bot _., © Friction gp bott (a) None of these Q.25 Which of the following is in violation of éSsumptions made in riveted joint analysis (@) Deformation ofplatesis neglected (©) Rivets are rigid (©) Stress concentrations neglected (9) None of these : [s-3 Ie It 2 1s Scanned with CamScannerans Fy 0 NDA OF Wot, ha 2 soit ho wi ol Hy ‘ion sl viol Night ofolonay Patton at ta) Chala (oy Snogor0«t (¢) Duawnon (2) Aol ho above Volt sam ack vat Minirutn pitch of ivotn in a rivotod joint (a) 2timo0 tho din ot Wot hay ent (bo) 26 tine tho dia of rivet (6) 28thmo8 tho total thicknon 48.01 tho main plato (@) 20tin0s tho thicknoss of hinnep nen H thinnor plate Mloctive longth of w tile 028 Tro ol 0 illot wold of te and sizo # 19 givon by ‘an (a) b- Vas (by Le () b- B () (020 Tho overlap of batten plates with tho main mmomibars in woldad connections should bo mora than (oa () 61 (c) 6 ( 8 whore t = thickness of bation plate (090 For a standard 45° fillet weld the ratio of size of filet to throat thickness is (a) 1:4 () 2:1 (9) 4:v2 (ast 31 The common assumption that, ‘al rivets share equally a non-eccentric load’ is valid at a load (@) bolow the working load (0) equal to the working load (©) above the working load (@) equal tothe failure load 032 By providing sufficient edge distance, which of the following failures of riveted joint can be avoided? (a) tension failure ofthe plate (b) shear failure of the rivet (©) shear failure of the plate (d) crushing failure of the rivet 233. Aspper 1S :800, the rivets subjected to combined ‘tensile and shear stresses are proportioned: jsuch the Ug eg D Pasian of Steet Structures Q.34 Q.35 36 as7 25 Wet We w (1) (ty “la Pe, py hy,(4 ») (4 MA sy (i) Ci) uy (J ) (c) - ota " (i ' n) 4y (4 y (c t 2A ba (i) ‘ i] Whore f,and fare ronpectivaly actual shear and fonsily strossos in a rivet and p, and p, are rospoctively permissible shear and tensile ‘trosuos in rivet, Ina diamond riveting, fora plate of width ti and tivat diarnoter 'd, the officiency of the joint is given by &=% wy 22 (=) (b= 20) @ m5 Oz Which ofthe following methods of design would be suitable for metal structures subjected to stress reversals and impact? 4. Simple working stress design 2. Rigid plastic design 3. Semirigid design 4. Elastic rigid design Select the correct answer using the codes given below: @) 1,2and4 (6) 1,2and3 (0) 1,3and4 (0) 2,3and4 For rvetsin tension with countersunk heads, the tensile value shall be (@) reduced by 25% (0) reduced by 33.3% (0) increased by 25% (@) increased by 33.3% When two plates are placed end to end and are [oined by two cover plates, the joint is known is (@) fap joint (©) but joint (©) chain riveted lap joint (@) double cover butt joint Scanned with CamScannertions 216 ultiple Choice Ques! wil be SIe856C 10 13, " me which rv! ( 0.38" Match List (Use) with List. (ype of weld) and Select tho corract answer using the codas given blow the lists List ‘A. Structural members subjectto direct torsion or compression B. Joining two surfaces approximately at right angles to each other ©. A hole is mado in one of the componen's and welding is done around the periphory of the hole . Pressure is applied continuously Ustl 1. Slotweld 2. Seamweld 3. Fillet weld 4, Plug weld 5. Butt weld Codes: A | I @ 5 ) 4 © 5 @4 5 2 Q.39 Consider the following statements: eese = oC Gono ‘Aluminum is being increasingly used for structural Purposes because 1. its modulus of elasticity is double that of stee! 2. its coefficient of thermal expansion is half that of steel itrequires less maintenance the strength to unit weight ratio of aluminum is high Which of these statements are correct? (@) anda (0) 2and 4 (©) 1,2and3 (d) Sand4 The rivets in an eccentricaly loaded riveted joint ‘are shown in figure below. 0.40 500kg Roy Ry (b) Vand 3 ™ {@) vand4 (d) 4and6 gand6 * ross-seotion of a standard fil er whoreandas’ (0) Handy ‘ and (d) 20" and 70° © sion plates np, ing ivots in cOmpreSSION pla py. ihe weather have 4 pitch not oy, mm oF ot 16 times the thickness of outside pj, {b) 24 times the thickness Of ouside iy, {) 32times the thickness of outside a, (¢) 36 times the thickness of outside ping, Attcy aat 0.42 Tackingvetsintension member, a6 poy, ata pitch in line not exceeding (a) 250m (0) 50cm (©) 60cm (@) 100m The effective section ofall Weld is epresereg byatiangle ABC with sides SS, and 5 sy, that S, > S, > S, 0.43 If the allowable shear stress in weld materials +, the resistance of weld per unit length is @) Sx () Sx © sx () Se The stee! parts at right angles, are welded wit filet weld of 10 mm size. The throat thickness of the fillet weld should be (@) 7mm (b) 10mm (c) 12mm (d) 5mm Which one of the following statements regarding the riveted joint shown in the given figue correct? O45 Q46 Scanned with CamScanner‘0 Piste noon av 6) inpaste theory al noe ) Bathin elastic and plas catty equal forces, (a) plastic thoOry tho outer res NY Oqual orceg Ne theories ail rivets all ives Aa carry Stealer proportion atlong, SMD az sat te correct statement a Material cost of a rivet ig ty ® 's highor tha abolt in that of, le strength of a bott ig Tens 's lesser tha of arivet, n that {@) Bots are used as a temporan whereas rivets are used as fastenings (@ Pivoting is less noisy than boting \ Y fastenings Permanent 18) When the bolts are subjected 10 reversal of |’ stresses, the most suitable type of bolt is {@ black bolt (b) ordinary unfinished bolt (@) tured and fitted bolt (@) high strength bolt 49 Aboltis subjected to shear force V and tension T.The capacity of the boltin resisting shear and tension respectively are V, and Ty, Which one ofthe following diagrams represents interaction relations? 19] 10 @) ww] (bo) wiv a to TH 19 44, 10 19] © vw (6) ww, Th 15 7 as (980 The actual thickness of butt weld as compared “10 the thickness of plate is usually (a) more (o) less (©) equal (a) None of these 51 Botts are most suitable to carry (@) shear (b) bending (©) axialtension —_(d) shear and bending Te. 3, 4g-4 Ag- 4 Sq. iS -4 St-3 { ¥y of a riveted joint, having the minimurn Bitch as per IS 800, is (a) 40% (b) 50% ~ (© 00 (6) 70% fos 0.83 The ratio of yetd stroxs in tension to compression in mid steet is (a) toss than 4 (b) greater than 1 (©) equatto t {d) None of these Q.54 Consider the nvoted joint shown in figure. The aximumn permissible value of 'p'(rivet diameter 20 mom) is (@) 50mm. (©) 72mm {b) 60mm {d) 96mm lf a bolt of nominal diameter 18 mm then gross. Gia for the standard clearance hole as per 7 18 800 : 2007 is (@) 19.5mm (©) 19mm. (©) 20mm {d) 185mm (Q.56) In which of the following cases is a structural fastener over designed? 1. When design is based on Unwin's formula 2. Long sustained loading leading to creep 3. When reversal of stresses takes place 4. Infatigue loading Select the correct answer using the codes given below. (@) 1,3and4 (b) 2and4 (©) Sand4 (@) None of these Qs7/ 20 mm diameter rivets are used to connect 10 mm ~~ thick plates. The permissible stresses for rivets in shear and bearing are 80 MPa and 250 MPa respectively. The difference of rivet value in single shear and double shear is (a) 27.6kN (b) 24.7 kN (©) 32.5kN (6) 34.2kN Som y & Scanned with CamScanner rm estions: Roe ze | multiple choice 24 rE \ O58 Iity cx and 9, is calculated shear and axial aso Q.60 Qet Q.e2 Q.63 tensile stress respectively in fasteners. $y 2° 7 allowable shear and axial tensile SUeSS tespectvely Then for safety of connections 2S er 18:00 is 4 (@) Hat, Stal <4 ty” Oy Mea , Sta © pt gees © (@ 4 St gy Facet Opal Which type of joint shows maximum efficiency in case of connection of two plates? (@) lap joint (0) single cover butt joint (©) double cover butt joint (A) all have some efficiency In which of the following case we avoid bolted ‘connection (@) connection subjected tofire (b) connection subjected to frequent earthquake load (c) connection subjected to snow load (@) connection subjected to corrosion problem IS 800 : 2007 is based on (@) elastic design method (0) ultimate load method (©) working stress method (A) limit state method Unit mass of steel and modulus of elasticity (as per IS 800 : 2007) (@) 7850 kg/m®, 2 x 10°Nimm? (©) 7850 kgim?, 2.1 x 108 Nim? (©). 7500 kgim?, 2x 108Nimm? (A) 7850 kglm?, 2.1 x 10°Nimm? The minimum thickness of a steel plate, which is directly exposed to weather and is not accessible for cleaning and repainting, should be (@ 4.5mm () 8mm (b) 6mm (@ 10mm 65 66 er Qe Q.69 Q70 igor the following statemeny, st diagrams f0r carbon rfpon contents: ‘arbon content increases 7 re timate strength of see! deg, 2. tne elongation befor fractureing 3. the duotty ofthe metal decrggg the ultimate trenath increases Winich of these statements are co, (@ 3and4 (b) 1and3 ( 1,2and3 (d) tand2 xctive flange area in tension rie eau (0 hy girder is equ! 7 a ie te te ) « varying 02! Ae (@) A, ema? A @) Aye Ate WENT vihere A, isthe area of each flange an, the web area. " Te order of elongation which a specinn, mild steel undergoes before fracture is (a) 0.1% (b) 1% () 10% (a) 100% ‘plate used for connecting two or more sturzy members intersecting each other is termed, (@) Template (b) Base plate (c) Gussetplate (4) Shoe plate Which one of the following stresses is independent of yield stress as 2 permsstt stress for steel members? (@) Axial tensile stress (b) Maximum shear stress (c) Bearing stress (d) Stress in slab base ‘An equal angle of area A has been attached? the support by means of alug angle. Ifalonatt stress in tension is f, what is the load canytd capacity of the member? (a) 0.5f4 (b) 0.8514 (0) o9ta (@ 1.01” The effective length of an angle membet Tiveted truss is equal to which one of following? Scanned with CamScannerens D esign of Steel Struct al (b) O.e5y ) 065! (@) os pero sthe centre to conta di tre nts Sd strength 400 eo of eld strength 400 MPa has boon pnastucture Whatis the valve ofthe mus alowable tensile strength? . ja) 2A0MPa (b) 200MPa (@) 120MPa (@) 96a stance between att ‘asteet plate is 300 mm wide and 10 mm thick rvetotnominal diameter 18 mmis driven, The ret sectional area of the plate is {a 1800mm?——(b) 2805 mme fo 820mm? (0) 8242mme 78 Tre capacity ofa single SA 100 x 100. 10mm as tension member connected by one leg only using 6 rivets of 20 mm diameter is (@) S33kN (b) 253kN ( 238KN (@) 210KN ‘Te allowable stress is 180 N/mm? 74 Incase of single anglesin tension connectedioy ‘one leg only, the net effective area as per IS : 800 is {@) gross area-area of holes 0) @ os 7+ 0.33(b/a) ‘Where a is net sectional area of connected leg 2nd bis area of the outstanding leg. Consider the following statements: Lug angles are used to 1. increase the lengths of the end connections of angle section 2. decrease the lengths ofthe end connections of angle section. 3. inorease the lengths ofthe end connections of channel section. 4 decrease the lengths of the end connections of channel section Which of hese statements are correct? (@) tand2 (b) 2and4 ©) 1,.3and4 — (@) 1, 2and3 We. 2 iy Q, arr Q.80 ast eniion member if one oF more than One | rivat 6 off the tine, the failure of the member depends upon (a) pitch () gauge (6) diarnetor of te rivet hols (d) Alot the above For double angles carrying tension placed back to back and connected to either side of the ‘gusset plata, the uectional area ofthe section, fo equal 0 gravs sectional aroa of (a) section (6) section plus area of rivet holes (©) section minus area of rivet holes (0) section multiplied by the area ofthe rivet hole ‘A tension member, if subjected to possible reversal of stress due to wind or earthquake the slendemess ratio of the member should not exceed (a) 180 {b) 900 (©) 250 (8) 350 Fora single section used as a tension member, the given areais assumed (@) 20% to 30% in excess of the net area (0) 30% to 40% in excess of the net area (©) 40% to 50% in excess of the net area (@) 80% to 60% in excess of the net area Match List-1 (Type of stress) with List-ll (Allowable value of stress) and select he correct answer using the codes given below the lists: ({, = minimum yield stress of steel) List- Ust-ll ‘A. Axial tension 1.0754, ', B. Bending tension 2. 0.66 f, ©. Maximum shear stress 3. 0.60 f, D. Bearing stress 4.0.45 f, Codes: A @ 2 (o) 3 2 @ 3 renee [ee oo Tacking rivets in tension members, are provided at a pitch in line not exceeding (@) 250m (6) 506m (©) 600m (6) 1006m $Huw 4 Scanned with CamScanner220 | Q.82. Faiture of tens; Q.83 Whatis the on member is considered when Cither of following statement is tue 1. Excessive elongation in member. 2 Rupture of critical 3. Buckling of member. 4 ion Shear block faituro of end connection. (@) t.2and3 (by 2, 3and4 () t3and4 (a) tanga lective net width of plate shown in figure tor carying tension? Hole ia 25 mm ‘All imenstons are in rm (@) 2125mm (b) 225mm, (©) 250mm (4) 275mm (Q.84° Bending compressive and tensile stresses Q.85 Ifthe yield stress of a structur 85 respectively are calculated based on (@) netarea and gross area (©) gross area andnet area (©) netarea in both cases (6) gross area in both cases ‘AS per IS : 800 - 1984, the ultimate load Capacity of tension members is (@) 06 1,4, (&) 067 5,4, © 0784A, — (@) 085 4, fal member made Then which of the hed, (@) Permissible tensile stress in axial tension — 180.Nimm? (©) Permissible bending stress in tension — 160Nimm? Of steel is f, = 230 Nimm?. following are correctly mate (©) Permissible shear stross — 92 Nimme (d) None of the above .87 When woangle section subjected to tensile force are connected to same side of t the gusset: Plate (back to back) then effective area is (as per 1S: 800: 1984) § 8-@ 84 © 80mm Lacing bars in a steel column shou! mang (@) Agece deduction for rivet holes eae 5A, +A, ‘kAy, k= SAYMSA, + A,) ia Bo AAs ke BAYGA, +) (@) None of these Eee Q. 88s per 18; 800, the chess of 99 given by sw (428° \ () fan \4 -a an Where Aand Bare larger and Smaller projecting | respectively of plate beyond column, Wgg: pressure on the underside of base and F, Permissible bending stress in slab bases \¥20 mm rivets are used in lacing bars, then | minimum width of lacing bar should be (@) 40mm (©) 60mm (2) 100mm | a9 ld bedes | to resist (@) bending moment due to 2.5% of the cone | load \ (0) shear force due to 2.5% of the columnost (©) 2.5% of the column load (d) Both (a) and (by Q.91 The channels or angles in the compres | Chords of the steel truss gicder bridges wf turned outward in order to increase \ (@) cross-sectional area | () section modulus (©) torsional constant (9) radius of gyration 2.82 Which one of the following pairs is cone! + Matched? | ) Truss Bending | (©) Beam Twisting | © Column Bucking | (@) Shatt Shortening } o 6 A j bs~~¢ S4-2 8 t 9L-3 Scanned with CamScanner cens Desi iG electric pole § m high ig 4 “9” of Steel Structures 21 f is fixea adation. Itcarties a wire into the v tourve sideways. The Stee Pandis ree 3. The slendemess ratio of the lacing bars for oe is ective lenath of the 4. CaMmressanshainotesesed TSO laced compression members are @ 325m (©) 40m provided with tie plates at ends. @5om () 10.0m Which of these observations is/are correct? gor @ compression member having th e tne most preferred section from the point sree of strength is view (@) Abox (0) AnL-section (@) Acirculartube (4) Asingle angle 4 Te pseserse ratio of lacing bars should not exc @) 100 (©) 120 (9 45 (2) 180 46’ Which one among the following is the correct = alo of effective length to actual length of a discontinuous angle strut, if ends are welded? (a) 065 (b) 085 () 10 (d) 12 a7, Ina gusseted base, when the end of the column “~~ igmachined for complete bearing on the base plate, the axial load is assumed to be transferred to the base plate (@) {ully by direct bearing (b) fully through the fastenings (©) 50% by direct bearing and 50% through fastenings (6) 75% by direct bearing and 25% through fastenings 88 Which one of the following values represents the maximum slenderness ratio of any connection member which normally aots as a tie in a root truss but can be subjected to possible reversal of stresses from the action ‘of wind or seismic force? (@) 150 (b) 200 40) 20 (a) 350 199 ‘Consider the folowing stipuiations in des'aning laced column: 1. Single lacing syste ms on opposite planes shall preferably be in the same direction sO that one is the shadow of the other 2. Lacing bar should be a fat section at 4 2 (a) 1only J ©) Benga (©) 1and3 (@) 1and4 Q.100 in ISMC 400 channels placed back to back at a spacing of 26 om carty an axial load of 460 tonnes. The lacing system should be = designed to resist a transverse shear of {@) t6tonnes ——_(b) 12tonnes (©) 8tonnes (@) 4tonnes 107 Which of the following is not a compression member? (@) Strut (b) Tie (©) Rafter (d) Boom Q.102 Slenderness ratio of the splices for compression members is @o () 145 — ©) 180 (@) 350 (@i8e-h0 ISMC 400 are placed back to back at a “spacing of 300 mm and carry an axial load of 160 KN. As per IS : 800 1984 its lacing system should be designed to resist a transverse shear of (@) 16KN (b) 4.00kN (©) 8kN s(d) 16.0kN Q.104 Permitted maximum slenderness ratio of a steel column under dead load and live load is (@) 180 (b) 250 (©) 360 (a) 400 0.105 The thickness of lacing bars for single lacing system should not be less than (@) 40 (bp) uS0 (c) 160 (@) 170 where [= length between the inner end of connections. 2.106 Siendemess ratio for single angle single riveted strut should be less than @ 180 (&) 250 (c) 300 (d) 350 Q.107 The permissible bending stress in slab base is (f, = 250 Nim?) * (@) 150'Nimm? ——_(b) 185 Nimm? (©) 165Nimm? —(d) 181.5 Nim? Scanned with CamScannerression i (2.108 Wich one of the folowing is a compressio! i member? i (@) Putin (b) Boom () Git (@ Tie 1 2.109 Battening is preferable when the i 4. Column carries axial load only . 2. Space between the two main components 5 not very large 3. Columnis eccentrically loaded : Thecorrect answeris (a) Only (c) tand2 (0) Only3 (¢) 2and 3 Q.110 The maximum slenderness ratio of compression member carrying both dead and superimposed Hi load is | (a) 160 (b) 200 i (©) 250 (@) 360 Q.111 Themaximum stenderess ratioof asteel column, the design of which is governed by wind or seismic forces is (@) 150 (©) 180 (©) 250 (6) 350 0.112 Consider the following statements: 1. Thetwo angle sections placed back to back ‘are most frequently used in roof trusses, 2. Abuiltup section consisting of two channel sections back to back s occasionally used. 3. The local bucking ofa compression member limits its size Which of these statements are correct? (@) Both tand2 —(b) Both 1 and 3 (©) Both2and3 (a) 1, 2and3 113! Compression members compased oftwo channels ack to-back and separated by a small distance are connected together by riveting so that the minimum slenderness ratio of each member between the connections, does not exceed (@) 40 () 9 © @ (@ 70 G72 cg etsincmpressen tts cotrpeed ~ to the weather, have a pitch not exceeding 300 mm or (@) 16 times the thickness of outside plate (b) 24 times the thickness of outside plate (©) 32 times the thickness of outside plate (A) 36 times the thickness of cutside plate Hinge we | (a 08 @ 12h @)2L | aut The use oftie plates in laced columnsis | “(ay prohibited (0) notprohibited | (©) permitted at start and end of acing sy, only (2) permitted between two parts ofthe lacing Q.117 Gusset plate is provided in column bas: connection to (@) reduce pressure that comes from underiny material to base plate (0) reduce thickness of base plate by reducny overhanging length (©) increase load carrying capacity ofcoum | (d) both (b) and (c) 2.118 Lacings are subjected to ~~ (a) transverse loading (0) axial loading plus bending (c) axial loading plus shear force (@) axial loading only 119 What is the maximum permissible slendemess Fatio for steel ties likely to be subjected ® | compression? | (@) 400 (b) 350 © 20 (@) 180 Ee Q ), 2.120 The allowable shear stress in the web of nif ‘Steel beam decreases with (@) decrease in h/tratio (0) increase in hitratio. (©) decrease in thickness (@) increase in height a a “his height and ‘tis thickness 13. Vipee ty Scanned with CamScannervia 8 os’ ind of the thang syite custard OF tO HINGE Of Hult un pp 3 gom the tne oF cONnECHION shoud ney oe Send # extend 107 (b) 867 (a 1804, pare Tis the thickness off theaess of web) nae and ithe _gpacnilevet amis 1 be atached to a cotunn uipch one among the following is the best comection? (@) Framed connection {p) Seated connection {@) Sitfened seated connection {¢) Endpplate connection {aasee! beams connected toa ste! column by (means of two angles placed on the two sides of the web of the beam. What is it called? {@) Stffened seat connection {@) Unsttfened seat connection (Framed connection (@) Rigid connection 1244 cantilever steel beam of 3 m span carries a uniformly distributed load of 20 kNim inclusive of self-weight. The beam comprises of 1SLB200@198 Nim, flange = 100mm x 7.3mm; web thickness = 5.4 mm; /,, = 1696.6 om*; 1, = 115.4 cm! What is the maximum bending stess in the beam? (@) 132.62Nimm? (b) 630.47 Nimm? (¢) 1949.74 Nimm? (d) 3899.48 Nim? 125 The heaviest | section for same depth is (@) 'sMB (b) ISLB () SHB (d) ISWB 2126 Generally the maximum deflection of a steel beam should not exceed 7 <2 of span (@ 535 ofspan 0) op q ck of span po gag tsar (0) 360 812) Consider the following statements: Agrilage base is checked {or 1. bending 2. shear 3. compression 4. webcrippling Wa are} 23 z ty ageie 3 Retin of Stel tue 0.128 Lateral buching of © exe} beam, is given by | 223 Which of these sta () tanga (6) 2,3ang4 ments are correct? (b) tand3. (a) 1,2and 4 oan 1 nok prevented by (@) shearconn (b) embedding comnor (0) bateraltracirg (0) increasing depth of web esion lange into slab 01294 stee! beam supporting loads trom the floor Slab as well as from wall is termed as (2) stringerbeam (bp) intel bean (c) spandrelbeam (d) header beam Q.130 The rolled steel section used in a cased beam has width “B mm and deptn “mm, The ‘minimum width in mm of the finished cased beam is given by (@ (8 +50) (6) [(B10) + 100) (b) (B+ 100) (@ 218+) Q.131 Fora cantilever beam of length L built-in at the support and restrained against torsion at the free end, the effective projecting length / is @r=07L (l= O75L SL l= 3L 0.132 Linder a concentrated load, bearing stress f, in w __wW © ena, [oeaniR, © ee 6 be (b+2nv2)t, (bem). Q.133 The area A, of cover plates in one flange of a built up beam, is given by @ 4-H tam © AqlotZom Zeeas “Zoe (8) Ae a.134 By how much percentage is the permissible stress in a gillage beam be increased if it is ‘encased in concrete (@) 15% (b) 25% (©) 33% (0) 0% AWSH-Q Vey 2 Bog 3a Scanned with CamScannerof span} each end SEAS Torsion, compression ange REMES. Accorcing to 1S - 800, he SST SEDS Comeression flange will fe the bearing lengin under Factions ay ‘the suppor is Calculated by @ ob. 28, ©) b+ 3p ©) dsasp (2) d+\3h "SN Of the bearing piate FEM Of root of me filet in mm f0 be tea. then ¥O for web Bucking andgagonat respectively ig where = clear depth ot ws T= wed thickness 0.138 Lateral pucks: 0D Between rocts of filet 99 of beam starts trom top ftange *recause of () compressonintop tange (©) citterent nature of forces in top ang botom fange (©) ‘ess value of shear torce over cross-section (2) None of nese ees Q.139 Economca! depth of 2 Date girders gven by Cr- w | O Ve OA | | i 7 | © 121 (@ 13/4 Vo. xt, \onxt of wed 0.140 Mimum spacing of vertical stfenerss ented © 35-3 3% BH2 qa = oat, @ as (©) ag © a2 (©) 203 _~ Where cis the distance be 2 ang 1.141 Consider the folowing statemeng, X=" design of wed and flange sp 1. Flange splice shall be BMatthe section 2, ange splice sha! be des, actual shear at the cection 3. Web spiice shall be des, actual sheat at the section 4. Web spice shall be. ‘Peds eto TED tra Which of these statements are con oo & (a) 1ana3 (©) Yang 4 (c) 2and4 ) 1.3ena4 ‘sider the folloning statement, Horizontal stitlener 18 provided nop 1. The depth ot wed is sma 2 Tendency to web buck 3. Vertical sifeners bec 4. Only tin plates are a Which of thes 915 less OME t00 clone, Wallable for wes e Statements are Coter (a) 1 and2 (b) 3and4 () t.2and4 1. 3anag (0.143 in steo! bridges. for span less than 3 teen A easr9 for hosted vences em, factor is taken as (a) 20% (b) 25% (©) 30% (a) 35% 0.144 Horizontal stiteners it the thickness of (2) <6mm (©) a5 (b) <5 (¢) >120 (9) = 60 where d = depth of web; y= thickness of web plate 0.160 Economical depth of a Plate girder corresponds to (@) minimum weight (0) minimum depth (6) maximum weight (d) minimum: thickness of web Shear buckling of web in a plate girder is Prevented by using (@) Vertical intermediate stifener (0) Horizontal stiffener at neutral axis (¢) Bearing stiffener Nene of the above WE2Consider the following statements; Bearing sifeners are provided ina plate girder 1. toavoid local bending failure of flange 2. toprevent buckling of web to strengthen the web 4. under the ‘uniformly distributed loads Which of these statements are correct? @) 1,2and3 (b) 2and3 () 1.3and4 (od) 1,2and4 1: 4 225 9.183 Fora welded Plate girder wit vertical stiffeners, Whats the maxinasn depth ot wel roviionable in design when the ticknose of the web plate i 5 mm? (9) 425mm (©) 1000 mm (©) 1250 mm (d) 2000mm Q.184 List contains Some elements in design of a EPL Supported plat gid and Listll ves Some qualitative locations onthe girder. Match theltems of wo lists. as per good design practice ‘nd relevant codal provisions, List-1 Flange splice Web splice Bearing stiffeners, Horizontal stiffener List-ti At supports (minimum) ‘Away from centre of ‘Span ‘Away trom support In the middle of span Longitudinally somewhere in tho compression flange pom> opens Codes: A Bo cop (a) oe olen M4 2 4 3 3 4 2 4 M1 5 2 93 G3 Horizontal sifener ina plate girder is provided "to saleguard against (@) shear buckling of web plate (©) compression bucking of web plate (c) yielding (0) All of the above Q.186 Minimum thickness of web in @ plate girder, when the plate is accessible and also exposed to weather, is (@) Smm (b) 6mm. (©) 8mm (d) 10mm. 0.187 When vertical intermediate stiffeners ate Subjected to bending moments due to eccentricity of vertical loads, their moment of inertia (cm) is increased by Scanned with CamScanner226 re, E = Young's m thi (Se Wed crippl KE NOS stress can be (@) incteasing the (0) providing sui (©) increasing he applied bend) jedulus in MPa. ickness of web, mm ing) moment KN-m Overall dopth of girder in mm ling due to excessive bearing avoided by the length of the —, ©) None ofthe above Gy Intermediate vertical stifeners Plate girders to {@) eliminate web bucking (0) eliminate to cal buckling (©) transter concentrated loads (©) prevent excessive dettectn ‘The depth of p @) ot span © Wotspan © Q.161 The maximum, eri late girder for long sf (©) W7of span, (9) 100 span (©) 10mm (9) 18mm Sen (0-162'Generally the puting Points 0 as to avoid (@) axial foros i (b) shear force: inratter inratter () deflection of ratter (©) bending moment in ratter Q.163 As per 1S: 800. for design of PB wt wa © 5 The maximum be urlins can be tab we oo we 5 Web thickness ‘able stiffeners bearing plates are provided in Pan is usually are placed at the panel nding moment ken as MADE py, 5@ to be . _ (0) 16 ae Bs ded, n industrial buy Q.165 Purlins are provided, ce dng ; too! trusses to carry dead loads, ye wind toads. AS per IS code, wig = 8 te assumed to be? {@) Simply supported (0) Cantlever (6) Continuous (@) Fixed what value (8a) she maximum 7 a urns or standard asbestos rajng en ? aa on (©) 14m | (©) 18m (20m 87 A building with a gabled root wi expetine | Pressure on its leeward slope which | (@) always positive (0) alwaysnegative (©) sometimes positive and otherwise Neate (0) 2010 (Q.168 The live load for a soy ~~" where access is not taken as (@ O65 kNme (©) 1.35kNim? PING FOO with slope 15: Provided to the roo, (©) 0.75 kNime (6) 4.50 kNme (©) By fixing them with rafters (©) By Providing sag rods () Allthe above (©) slope of roof (©) both (a) ang, (b) None ot the above 0.171 The wind toag (b) Shape of structure {c) location, ‘shape and height of structure } (d) Stabe and heightotsiense 2 G1 6303 Lary ‘i Scanned with CamScanner227 é ens! Design of Steel Structures Ayes! weight of f0of truss in (Nim?) may be ot 2 (a) (2 b } gt pisined DY a @2 7 @ 3) 2 (§+5)x10 0.180 The intemal pressure coefficient O° bar 1 l buildings with large permeability is tat @ 4) (5-910 (@) 102 0) 298 desi \ (o) 407 @o 1 tuss design, snow load need not sored when ool is steeper than Be 6.181 The risk coetcient ky depends Om oe (b) 15° w {@) mean probable design life of str oe os (0) basic wind seed (c) both(a)and(b) (6) None of these me range of economical spacing of uses ments isjare tue? a ats rom 0.182 Which of the following state a ustol §—(b) Lato 2i/s see ifthe spacing of russesis large, the cost Of (o u2t0us (@) 2U5 to 35 these trusses per unit area decreases but ) industrial buildings in northern hes the costot purinincrener | (rein srisphere trusses, the OP ve aavantage of a northight roo is that it 2 ee aay tote the f@) alos sunlight into the building, costoftusses sou be caval ves re | (9 flyexplains the Aurora Boreas aS (@) paris difsed dayight into the buicing a | ‘and helps avoid glare of direct sunight Coe eee areal {@ allows both sunlight and the prevailing o pee mary eae in the built i nothem breeze inthe building fe ceds (o) 1.2end3 a qitApat from gravity loads, which of he folowing “jas are also considered in the design of a ae gat gitder located withinan industial building? q 484 The shape factor fora solid circular section of 4. wind loads — i ! 2. longitudinal loads diameter D is equal to 3. lateralloads az w 2 Select the correct answer using the codes given an 2x below: 16 nD Codes: © on @ 8 eta a we 2.184 For steel structures proportioned using plastic . design, the working load (dead load + imposed load) should be multiplied by which one of the 177 The maximum permissible span of asbestos following minimum load factor? ‘cement sheets is (@) 650mm, (o) 810mm (@) 13 (0) 15 (9 1250mm (@) 168mm (© 17 (20 {85/1 a plastic analysis of stuctures, the segment between any two successive plastic hinges is ‘assumed to deform as 2178 Normally, the angle of root truss with asbestos ‘sheets should not be less than (@) aK (o) te a (@) Aplastic materia! o) A ? {1797 minimize the total cost of @ roo! truss the fa fipesae ea i 4 puns tio of the cost of truss to the cost of ps (d) An inelastic material Scanned with CamScanner: 3. a : inthe figu | Je Choice aan tho tuea, | = a torn De 9 ta union ment capacity M, ' ane paste morn . rectmaxiru” 5 isthe cor 0.186 Which one ofthe fling s apace shear capacity ofa prismatic beam dosign of steel structures? (@) O5A,F, (0) OSA, (0) 0.75A,F, AF, 0.187 Match List (Loaded prismatic beat uniform Mg) with Listll (Plastic Load) and selec! ie correct answer using the cade given below the lists: List+ List-l Ferd ete Um LO H_f_4 Mp af a Lge Lat Codes: A B Cc OD @a4 3 1 2 w1 2 4 3 @4 2 1 3 @1 3 4 2 Q.188 Match List! (Shape of structural) with Listll (Ghape factor) and select the correct answer using the codes given below the lists i, wr span BC, WL thon, o econo) ior of plastic hinges formes, anindeterminate beam with redundancy Rs. 0,190 What is the nut become determinate? (a) R-1 (bo) R () Ret () R+2 19) The cross-sectional area and plastic ve * modulus of the given section are respecte, mm Cit List-1 List-II 0 em ———t A. Rectangular 1,20 {a) 600 mm?, 10,000 mm® B, Circular 2.111012 (b) 700 mm?, 8650 mm* C. I-section 3.15 (c) 600 mm?, 9750 mm* D. Diamond 417 (0) 700 mm?, 10,500 mm* jes: cots ec 0.192 A load P is applied at the middie of 2 51 masa Supported beam of span L. tne beams 72 Hee Of ductie material, and M, isthe plastic ra"=" 3 4 2°41 ‘What is the ultmate value of P? Pa as sm. gam Oo it st Qeq 88-9 24-3 be Ri oe t \ | | | | | | { ' Scanned with CamScannereas ends carties UDL throughout he span. What is, th rato of collapse load to yiold tong 9 4 3 es) I @5 w 3s 5 3 Ss a @3 3s 01864 simply supported beam of unitorm cross: section has span Landis loaded by a point load Pat its mid-span, What is the length of the alastoplastic Zone of the plastic hinge? @ oe ro @ % (0196 Ina T-section shown in figure below, whatis the distance of plastic neutral axis as measured down from top? 400 mm $s E 8 E 8 = 100mm (2) 100mm (6) 150mm (© 200mm (©) 300mm 197 A the location of a plastic hinge, (2) radius of curvatures infinite ©) curvatures infinite ime as ~ tee 4 6 Desi 90 of Steel Structures | 229 ed cantilever boam - eee "22 Of uot mom 2 eazy M, 1 shonm in ture pur MN (©) momo isto w (4) Hoxio stron inti + + Q.198 Tho mechantam method and th statical mothods — tive slam (2) lower and uppor bounds raspactivaly on the what is the collapse load wy strongth of structure vont 12 8, (6) upper an lowor bounds rospectivoly on the @ Ge 7 uM strongth of structure, 6 3 (c) lower bound on the strength of structure @ 7% (©) TM (2) uppor bound on tho sirongth of stiuctura ing cross-soetions in th a1stAnismatcbeam (shape tector, 5 faadatban 2°89A%TaNGD tho flowing cross-sections In the increasing ardor o their spoctive shape factors TQOA (Sec ted (©) 1<3<2<4 We 25 mm Nominal diameter According to Unwin's formula nominal diameter of ‘vet is given by, 9= BONt $= Gowig = 2404 mm Maximum pitch of rivets in compression = 12t0r 200 mm whichever is less ie Design of Steet str 231 gt ructures @ & @ 8&8 ay 6 @ «68 @ 87 ) & © B &% 4% @ % © % 101, (b) 102. (a) 103. (b) 104. (@) 10.) 110 @ 1, 12) 117, (b) 118. (d)— 119. (b) 120. (O) 125. () 126. (ce) «127, @) 128.) 133.) 134.) 135. (@) 136.) 141. (a) 142. (0) 143. (b) 144. (b) 149. fa) 150. (a) 151. (a) 152. (0) 187, (b) 158. (©) «159. (a) 160) (©) 165. (6) 165. (b) 167. (0) 168) (a) 173, (d) 174, (a) «175. (©) «176. «) 181. (c) 182, (d) 183. (c) «184. (©) 189. (0) 190. (b) 191. (e) 192) 197. (b) 198. (b) 198. (©) 200. (C) 205. (a) 206.) 207. (b) 208. (A) Inthe case of double cover butt joint, eccentricity cof force does not exist and bending is eliminated whereas it exists in the case of lap joint. The tension and tearing of plates can be avoided by providing enough edge distance and minimum pitch distance. The distance between centres of two adjacent rivets, in a line lying in the direction of stres:. shall not exceed 16t or 200 mm, whichever is less, intension members and 12tor 200mm, whichever is less in compression member. + Ole distance = Lesser of (16 x 10, 200) 160 mm : For shop rivets permissible stresses are, In shearing, t, = 100 MPa In bearing, «, = 300 MPa Scanned with CamScannerMultiple Choi The gross diameter of hole (D) = 164152175 mm Strength of rivets in bearing = Dis, = 175 26 2 200 = 315 #N Strength of rivets in single shear xO x = a, = Fx x 100 Oye, = En nse = 2405 KN + Rivet value = 24.05 kN. Hence, number of rivets required 20 303 «4 24.05 ced maa Permissible tensile stresses in bolts used for Column bases is 120 Nimm?, ‘The safe load that can be transmitted by the filet welded joint is given by, s Py i Gx108 = (€0+50+60)x © «108 ve 77895 N = 77.895 kN When a load, W acts on a rivet group then the rivets are subjected to two forces, w 1. Force due to ayia load, F, = ‘n= total number of rivets 2. Force dut ot moment M on any rivet , « ¢ 1r= distance of the rivet from the C.G. of the rivet group when load line coincides with the C.G. of the rivet {group i.e. non-eccentric connection then the rivets are subjected to shear only. Friction grip bolt is also called High strength {riction grip bolt or HSFG. The fatigue strength of these bolts is more because of no stress Concentrations in the holes which makes it suitable to withstand reversal of stresses The width of the main plate required is less in case of diamond riveting, The critical section is diamond Mroe ga through One OF Na river ting passes throug = ns of th plate FEQUITED 0 accor. vonond pattern siessthanthatfor cha, i in- 1). by Number of rivets in chain riveting a nal . A set ex ameter os Minimum pitch = 25 tmMes the nomial cag, “The effective length of a filet Weld is equ overallength minus twice the weld sie, Thees, tength of a filt weld designed to transmt i should not be less than four times weld gq For a 45° fillet weld throat thickness t= 3 ,... of the weld. ‘Actually the outer rivets are subjected tog shear as compared to the inner rivets assumption that all rivets share equally a rz, eccentric load is approximately valid when ve cconnectionis subjected to static loads approach ulimate strenath Efficiency of riveted joint, Strengthofriveted joint, ‘Strength of solid plate 0 1992 P. 1262 100 The section 1 ~ 1 is most critical. The streng? joint at section 1 ~ 1 is (b- ata, ‘The strength of solid plate is b to, Son = 245 100 The rivets are assumed to resist the load €0:2" inthe elastic theory. Actually the outer rivets C2 Scanned with CamScannerpe PE as conor to rtsin tho mito roe plo G ne fad is inoreasod, ho Moro highly we Tt tart yeh ar ai thro tli” of load among rivets, The fallura will panies hav itd and th erngth ou of OE is oqual to tho strongth of o ore! ‘multiplied by the number of rivats p je interaction equation for a high tonsion bolt puncte ORT and tension is : ‘This oquation v (2) $1 isropresontod fA % by diagram (b) pcearing 1018: 800, tho ros and als Aestc0d tbat shear and terion shal be SO ved that the calultod shear and la 1 excoed the respacive allowable forces do net forces Le. Vv T —24 3 Rn single shear = min. of © Za? x ty jo, xdxt 2 B,,21.5' X60 _ 99. 04kN =minot {4.1000 250%21,5%10 _ 64 75kN 1000 x axtd® xt, in double shear = min. of “ o,xdxt min, of {58.088N 53.75 kN 4.7 KN Difference = $3.75 - 29.04 (a) 233 Design of Steel Structures — Ca tovipratio” coptible cur athquako, tae Bocaus bolted joints ate and in caso of froquent nas bean ymottiod hod. 1g ; 800. " into dosiat ing sos 10 stool structut idoring tint odon work Now code of formattod by £0" hilo arhior on0 We sion] Directly | oxposad [or cl ho woat Joaning) rn) Mi 2 imum influence on {he ‘Carbon has the maxi mechanical propertios of steel jron-carbon alloys Containing up to 2 per cant carbon are called carbon steal while those 1 2% are called cast stoc!. With incr strength of steel increas con having more that ease in carbon the tensile ‘0s but the ductility falls. Effective flange area = +g Not area of the flange = A, +e ge For mild sto! ()_ Proportional limit (190 ~ 220) Nimm? {i Yield strength (230 - 250) N/mm? (ii) Ultimate strength (410 ~ $30) Nimm? (iv) Fracture strength (250 - 300) N/m? (¥) Elongation at fracture (23 ~ 35)% Thus the order of elongation is 10% Base plates are provided to distribute the load of a column on greater area. Permissible values: Axial tensile stress = 0.6f, Bearing stress = 0.751, Maximum shear stress = O.45f, Stress in slab base = 185 MPa forall type of steels Scanned with CamScanner| mani E tions 234 multiple choice QUe5 pe benaing ass nes y pers OO ire? Strength of member = allowable tensile ste9S * Net area of the angle Net area = Gross Area ~ deduction for Noles Maximum allowable tensile strength f 400 = ch. = 490 . p99.52 MPa ier * ier * 5 Net sectional area of the plate is given by. Ag = (B= nd)xt = [300-1 x (18 + 15] « 10 = 2605 mm? ai ‘The net area ofthe tension member is GWEN PY: Art = Ay + KA A= (100%) <10-c 5x10) = 735 mm? Ae (100-9) «10 = 950 mm? ‘The angle section is connected by one leg only. ee ee * = Gash, ~ 3x75 +90 = 07 735 + 0.7 x 950 = 1400 mm? = Oy * Arar 480 x 1400 x 10° = 210 kN Lug angles are sometimes used to reduce the length of the connections. However their main purpose is to accommodate more numberof rivets so that size of the gusset plate may be reduced. The three criterion for failure has been considered innew code. Buckling takes place in compression members and not in tension members. « Permissible tensile stress in axial tension .6 f, = 198 Nim, 0 (2) Pe vt ing barsin riveted, Minimum with of 20108 _ should be as follows: Nominal rivet : fiameter(men) 2 20 18 16 width of lacing pars (rn) 65 60 55 50 The lacing of compression members shovgp, Gosigned to resist a transverse shear, V=25¢ Gf axial force in the member. ‘ rar ingle lacing ystom on 10 Parallaces py foree (compressive oF tensile) in each ba, F= D5in6 For double lacing system on two paral plang, the force (compressive or tensile) in each be Vv Fe sine Ttis equivalent to a compression member whee one end is fixed against rotation and positon nd the other and neither restrained against rotatin ror fixed in position in the direction perpendus | to wire, So effective length = 2L = 10m. | In the direction of wire, the pole is hinged at wie end so effective length = 0.6L=40m | Slendemess ratio, = 7 Lesser the value of 2 (greater radius of gyraiont | the column can take more load, Maximum adi | of gyration is obtained when material is farthes! from centroid, Therefore box section is best For single angle discontinuous, (0. One rivet or bolt ~ Effective length is % distance between the centres of end festering (i) Two or more rivets or welding - Etech length is 0.85 times the distance betwee? node points. Scanned with CamScannerens ., colstn on an QUSet matt re nop fosamactined 10° Complete bearing qe fxanasaf0dO3IIEG Fr tho ttl oteay re yansterred. It they are facedimachined for plteboarng, 50% ofthe forces arotaetence seecty BY He COMM and 50% thvouae jateners ge ‘pelacing bar may be a lator angle section. The purpose of lacing is to hold the various parts of a column straight, paralle! at a correct distance apart and to equalize the stress distibution petween its Various parts, The slendemess ratio ofthe lacing bars for compression shall be loss than 148. ‘The lacing system is designed for a load which is 25% of the axial load i.e., 25 Pawson = F9p % 180 = 4 tonnes ‘rut is a compression member used in the root truss and bracing, Rafter or principal rafter is a top chord member in a root truss, Boom is the principal compression member in a crane. Tie rods are sag rods provided at the crown of truss used in industrial sheds. These cut as tension members and resist the tangential components from the two sides of roof truss. Splices used in compression members are ‘assumed to act as short columns with zero slender ness ratio, Bai Lacing is designed to resist a transverse shear Of V = 2.5% of axial force in the member, 25 Fa * 100 = 4 kN bm 5 o Design of Steel Structures 23 te Maximum slendemess ratio Type of member ‘A member carrying ‘compressive loads resuting from dead load and ‘superimposed load ‘A member subjected | to ‘compressive loads. resulting ‘rom windlearthqueke forces ‘provided the deformation of such members does not adversely affect the stress in ‘any partof the structure ‘A member normally carrying tension but subjected 10 reversal of stress due to wind or earthquake forces 250 0 Minimum thickness of lacing bars, 1 1140 for single lacing # UGO for double lacing riveted or welded at intersection. Strut is a compression member used in the root truss and bracing. They are of small span and may be vertical or inclined, The principal rafter is a top chord member in a ‘oof russ and booms the principal compression member in a crane. Column, stanchion or post is a vertical ‘compression member supporting flats or girders in a building 120, According to 1,8. 800-1984 the maximum permissible shear stress should not exceed the value of, giVEN By ty, = 0.45 f, The permissible average shear stress +,, on a web whose depth does nol exceed 85 times its thickness, is equal to 0.404, The allowable shear stress in the web of a mild steel beam decreases with increase in hit ratio. ‘And for same At ratio allowable shear stress decreases with increase in spacing of stiffeners, ry As per IS: 800-1984 Clause 6.7.4.4 unless the outer edge of each stiffener is continuously Scanned with CamScannermrp, IE = Multiple Choice Questions wy Stitfened, the outstand of all stifeners from the 2560 Web shall not exceed “> for sections and 12f t {or flats where ‘t is the thickness of the section or flat, ‘The beam column connections expected to resist and transfer end reactions only are termed a5 shear connections or flexible connections. These permit free rotation of the beam end and do not have any moment restraint. Bracket connections, ‘seat connections (unstiffened and stiffened) and framed connections are of flexible type. The other type of connections which do not permit ‘any relative rotation between the beam and column and are expected to resist moment in adcition to end reactions are termed as moment connections or rigid connections. For cantilever arm both moment and end reaction is to be transferred without rotation and therefore rigid connections ‘would be the best choice. Clip angle connection, split beam connection and bracket connection (end plate connection) are rigid connections. The maximum bending stress is given by, 2 20ng But, Mpg, = ME ae = 90 kN-m Tgp _ 1696.6 x10" 2° Door 400 = 169660 mm? 0x1 A fone = FpgE @ 990-47 Nim The giillage base essentially consists of steel beams encased in concrete. They are provided when, (i) The load on the column is very heavy. (ii) The bearing capacity of the soil on which the concrete block is to be placed may be poor. They are designed for bending, shear and web crippling. a irder is adjusteq depth of plate di o Peas ‘ertweight ofthe girder and nats red economical depth of plate ggg O= Ney hy ‘Allowable bending stress in tens, Sw me Vertical stiffeners are provided at the spac 0.33 dio 1.5 dwhere dis the distance bay the flanges ignoring fillets and if hogan stiffeners are also provided d is the mayin ‘lear depth of the web. Spacing can be req, rear the supports where the shear force's, compared to the centre of the girder fa ‘As per clause 6.7.4.6 of 1S: 800-199) | intermediate horizontal stiffeners not subiecedy, external loads shall be connected to web 5 | rivets or welds, so as to withstand a shear force, between each component of the ster | and the web of not less than, 125? a kN/m | } | | { Unequal flange angles with long horizontal gs | are provided to serve the following purposes: | 4. Toincrease the moment of inertia ofthe sect, | and | 2. A large length is available for making te | connection with the flange plate t | | ae IS : 800-1984 recommends the provision of we? stiffeners as follows: (i) a 'S lesser of Bie te Finca Ge \ No stiffener is required. | g, i) 2 << lesser of 3200 and 200. vetiot hy stiffeners are provided, Scanned with CamScanner4 ens! De: : sign of Steel Structures = 4000 2 250. Verto sifeners and one horizonta gaton TOM the comressontace eg to twortths of the distance. rm compression flange to the neutral axis aa provided. eee de or s lesser of we < lesser of S400 Ye od 400. The requirement is the’same as in (i (ii) plus horizontal stiffener at the neutral ie . where d, = 2 x clear distance from compression flange angles or plate or tongue plate to the neutral axis, Bearing stiffeners are provided under the concentrated loads and end reactions. It serves ‘wo purposes. {) It prevents the web from crushing and sideways (lateral) buckling under the load. {i) Itreieves the rivets connecting the lange angles and web from vertical force. Vertical stitiness are requited in a welded plate girders when, 2 >85 and 2200 yy > 85X5 = 425mm yg, $200%5 = 100mm The depth of plate girder usually varies from 1/8" to 1/12 of its span. Purlins have a tendency to sag in the direction of sloping roof and sag rods are sometimes provided midway ot at third points, between root trusses, as desirable to take UP the sag. These feds reduce the moment My, and result in & ‘smaller purlin section. Qe Purins are assumed to be continuous beams. Internal air pressure depends upon the degree ‘of permeability of root or wall ae The economic spacing of the truss is the spacing that makes the overall cost of trusses, purlins, roof coverings columns, etc. the minimum. The spacing of the roof trusses can be kept 1/4 of the span for up to 15 m, and 1/5 of span from 45-30 m spans of roof trusses. It includes both internal as well as external pressure, ae The initial slopes and deflections of the beam do not affect the virtual work equations. Thus the displacement diagram can be simplified to consists of straight and undeflected lines i.e. figid deformation, The maximum shear capacity is 0.55 Ay/, et eo Fixed Beam 2Mpl Po ab for a= b=U2 8M, p= OMe v ——— Scanned with CamScannerea Li , = Multiple Choice Questions ~ the degree of redundancy. Howey, a complete collapse of the Beam (py va hinges will be required. P me Total area, A = 5x 60+5x60 Ke ae if ‘Assuming hinges at fixed end and under the load. Using virtual work method, TTT MA20 + 30+ 0) = Pxexa04Pxto = ALB i 6M, Po Peemtimronng The centlds of hal arees on ete So, G are at y, = 30mm, ¥, = 2.5mm fe 7 =) i ic section modulus a, i i, Therefore plastic : Ano Jit = 5 Wr*I2) = 300 x (30425) PXDXIXS x0 = Ma(0)+M,(0+0)+M, (0) Sees p. 1M, Z De The simply supported beam is a determinate on, hence one plastic hinge will be requited for ig Complete collapse. This plastic hinge wil be, Total number of plastic hinges needed for complete collapse of the beam may be given as, Number of plastic hinges, Sr+1=@3-2)4122 Mp w formed under the load. Hence the maxirun osm, oS, bending moment can at the most reach tote plastic moment M,. By principle of virtual work, we get, PL ~ Mad ~ 09 49-09 Mp x 28 + Me > +WxOx2=0 Wx 20 Number of plastic hinges required for compl? collapse = r+ 1 190. =(8~2)+122 The Plastic hinges wil be formed under the oa? The number of plastic hinges required to make and at the fixed end of the beam respeciveY an indeterminate beam determinate is Rwhere A Scanned with CamScanner| | | Wab — Mob a+b Me Wxex lla Myx Wetxtid u aria = Mos exh 2 MEL Se ge 4 4 The collapse load for a prismati ic bea both ends and caries UDL througherr meat i is given by, ahout the span 16M, w, = — >= . e (i) where Mp is its plastic moment. Plastic moment Bu, s = este moment Yield moment Mp. > sa M, (i) w 2 Al - so, My = (ii) Substituting value of S from (ii) in (iii), we get, Mp WE Ss 4 Substituting value of M, from (i), we get, we _ we 1S 12 Ww, _ 4 » 24s w,~ 3 Total area, A = 400 x 100 + 100 x 500 = 90000 mm? A, 90009 _ 45000mm* 2° 2 239 Thus the ng Plastic neutral axis lies outside 40000 "9°, Because the flange area is only me Let the plastic noutal axis les y mm below the Iunction of tange and web, "9% 100 = 45000 ~ 40060 = 50 mm + Plastic neutral axis vis. as measured from t flange = 100 + y Pe = 100 + 50 = 150 mm Ee ‘The static method represents the lower limittothe ue ultimate load and has a maximum factor of safety, Shape Factor 112 Ww COC|A 23 200, Because maximum bending moment develops at end A and between mid span and end 8, If the number of plastic hinges in the collapse mechanism are less than (r+ 1) the collapse is called partial collapse. In such a case, part of the structure may fail making it useless as a whole. If the number of plastic hinges in the collapse mechanism are (r + 1) the collapse is called complete collapse. Such a mechanism has only one degree of freedom. If the number of plastic hinges developed are more than (r + 1), the collapse is called over complete collapse. In such ‘case there are two or more mechanisms for which the corresponding value of the load is the same, this load value being the actual collapse load, Scanned with CamScanner240 | "the degree of in a Plastic hinges developed is NM then, < (041) Paniat colapse re ‘+1 Complete collapse > 641 Overcomplete collapse Channel sections are best suited for purlines, An L-section is Preferred for Girders. th For collapse in iy \ DAN a 4 bh 9B 4 = pp Ste For collapse in Hl baa 6M, +. Minimum load for collapse = —~® Multiple Choice Questions : [4 \determinacy is r, and the number MBL », Ege Told stron Factor of sally = lowsble utes Vit inroa%® in OH He, 15 op safety vill touce to 5 = 1.26 Load Factor = FS 7 shape factor 21257112 © $1.49 ‘The dogree of indeterminacy, r= 2 Number of plactichinges need tor entgy art Using virtual work method, L M+ Mf20) + 4M,0-= Px 50 = Ps ‘The other possible mechanisms, b— 2 —— 35 ph — iy — Using virtual work method, Myl8,) + Myl0, + 0,) + 4M,f, = Pa, Scanned with CamScanner 4