Question

Q3. Can you describe the efficiency of lap joint in bolted connection? Compute the efficiency a lap joint as shown in figure with the following data: M20 bolts of grade 4.6 and Fe 410 plates are used. Pitch distance = 70 mm and edge distance = 35 mm. 22 mm 22 mm 60 mm 280 mm If the same plates are connected by butt joint using two cover plate of 11 mm thickness and 8 numbers of bolts on each side. Compute the efficiency of butt joint. Express your opinion on how the efficiency are different for lap joint and butt joint form your results. (9 marks)

Answer 1

given 60 Gommy 80mm MPO te 410 plates bolt 4.6 P = 70mm e=35mm tub= 400 num? tyy = 2400/mm2 lub point, single shown , poume failure Plone fant en through dink shear capacity Volpb= (Anxon) БҮm - 400 184,25 (Teyg y 2o'x) blow = 45.250 KN

(11) bearing capacity Vaub= 8.5 kb dtfy you ) th = = mm 35 3822 70 -.25 3422 410 Ikb=5303 Yorb = p. 54.5303 X 90X 22 X 400 125 | Vaub = 186.666kN (1) net tensile of plate rupture TON = grunan An= P.dolt 1.9X410X( 70 - 22)822 1.es Tdm = 31173/KN ty plate=250 70 X22X250 1:1 (w_goom_gjelding of porte Ag fy Ymo Tag = 350kn Tag =

efficiency of lab gohut. Vabb, vdub, Tag, Toal) Tag 45.250 350 V100 = R.92% Thence efficiency of lap Joint = 1.92% Cork but Joint 22 mm imm 280mm 9 double cover but Joint- no. of shear plames=2 apaume one is passing through threaded shank & other is pansing through plane shank,

(i) Valpb fi mayant heyat) S3XY - 400 381.35 I Volpb= 103. 26kH ( bearing capacits it = min/tmain, ext cover) ta min (22, 2x11) t=22mm kd= .5303 Von = 2.5 kb dt ify PSX.5303X20X22X400 1:25 Udv = 186.67 KN Tag & Tan plate will be same as lap Joint Tag = = 350kn TONE311 KN

eficiency of butt gulint - men var min (valse, Velvd, Tani Idy) Tag 103.26 -X100 350 = 29.51% Thence of but Joint = 29.51% efficieny of lap sont & butt point wille different is calculated above it no. of botts increase per pitch length. in this case we tape provide single line bolts, if bott lengs double then efficiency of both the soints will be decible. are na.