1、3.1 解：一、設計為對接焊縫a = -A = '25-* ° 208.3N/mm2 > ffV =1S5N/mm2&500x12不滿足要求，改用斜對接焊縫，取切割斜度為1.5:1,即tan 0=1.5, 0=56 ,斜縫計算長度為Zw1 = 5° = 603mmsin O此時焊縫的正應力為Nsi n。1250x1()3x0.83 1，, w .OCAT .，=14-3AN /= 1S5N / mmAl-t 603x12 w前屯力為追.刀力NcosO 1250x 10 x0.55rw 1=95.ON/mm < f = 125N/mml-t 603

2、x12二、雙拼蓋板圍焊縫取拼接蓋板的寬度為 b=450m m,設拼接蓋板的厚度為 t2 ,拼接蓋板的鋼材取為Q235,根據強度要求，拼接蓋板的截面面積應不小于鋼板的截面面積，Bti 500x12 , r即 2 btzABti , t2 >=6 J min , t2=8mm,2b 2x450由構造要求確定焊腳尺寸：hf min = L5 J 11 = 1.512 hfmax = & 一(1 2) = 8 (1 2) = 7 6mm所以可以取焊腳尺寸 hi=6mm,角焊縫的強度設計值為f"ON/mm2 ,則端焊縫承擔的力為：N、= "Ehelw = 1.22 x

3、160 x 0.7 x 6 x 450 x 2 = 737.856?側面角焊縫承擔的力N'=N N'=K £hLi=N L160x0.7x6x(/ irl-6)x4 = (1250-737.856) x 103解得 Lvi = 196.5 2 Z,取整得 / 皿=197 mtn在兩塊鋼板間設 10mm 的接縫，則所需蓋板的長度為 / = 2x197+ 10 = 404mm, 取 整為 410mm。最后選定的上、下拼接蓋板的尺寸為2-450x8x410 1 1 專2 269x12-69x3,5 =725kN.“ kN/m，計算焊縫截面的幾何特性280X10323 _ (

4、280-8)x1000*Swi = 280x16x508 = 2.28x10 6mm3W 1sw = 280 X16 X 508 + 8 X 500 x 250 = 3.28x10 6 mm3 w三、應力驗算< =n5N/mm 2< -125N/mm3、“ 1點的折算應= 71 722+3x16.502 = 174.36N/mm2 < 1.lf; ' = 1.1x185 = 230.5N/mm2滿足強度要求。、三面圍焊又構造要求確定焊腳尺寸:'hf 訕=l-5yt =1.5116 = 6mm肢背“hfmax =L2fmin = L2 x 10 = 12 7Zh

5、fmin =.5yihfmax = 1.2 將=1.2 x 10 = 12/wn=6mmhfmax = ? (1 ? 2) = 10 一 (1 ? 2) = 98mm因此，角鋼肢背、肢尖焊縫焊腳尺寸均可取為為 fw = 160N/mm2 ,計算時取一個角鋼計算，則單個角鋼軸向拉力為hf=8mm,角焊縫的強度設計值"=AA =500印，查表3.3可知肢背kl=0.7,肢尖k2=0.3oN3 = J3(fAhelw3 = 1.22 x 160 x 0.7 x 8 x 140 = 153036&肢背 M 二 k& 竽=0.7 x 500000 - 53 : 6.8 = 27

6、348 i6N肢尖 N, = k,N -宇=0.3 x 500000 - "3 36? 8 = *>4-22肢背、肢尖焊縫計算長度為繪 273481.6 =30A hefA' 0.7x8x160,N,佬佻務骼-82mm肢背焊縫的實際長度為 /)= / + hf = 305 + 8 = 313mm ,取整為320mm肢尖焊縫的實際長度為 /2 =/m ,2+/?f =82 +8 = 90mm，取整為100mm肢尖的焊腳二、僅設計側焊縫時，根據前面角鋼肢背、肢尖的焊腳尺寸結果，計算角鋼肢背、尺寸也可均取為 hf=8mm, 此次計算按兩個角鋼焊縫一起受力計算。"kN

7、 = 0.7 x 1000 = 700kNN2 = 0.3x 1000 = 300kN700X1032" 2x0.7x8x160= 390.6mm300 xlO 364mm. 滿足構, 9 = =- = 167.4mm2hef；v 2x0.7x8x160 /,，! < 60hf = 60x8 = 480mm,/,i > 8h f = 8x8造要求 Iw2 <60hf = 60x8 = 480mm,如 8hf =8x8 = 64mm.滿足構造要求肢背、肢尖焊縫實際施焊長度為4 = ZwI + 2/f =390.6+ 2x8 = 406.6 , 取整為 410mm/2

8、=/H.2+2/7f =167.4+ 2x8 = 183.饑泌 ,取整為 200mm。焊縫受力剪力V=F ,彎矩M=Fe52x5.6x200x100 + 150x5.6x(200 + 12 + )+ 5.6x(150-12-5.6x2)x(200，)2站-6述00 +-i-50x5-6-+5.6x(-'50-'i2-5.6x2)=144mmIw = x5.6x2003x2 + 2x5.6x200x( -144)2+150x5.6x(200 + 12 + -144)2J+ 5.6x(150-12-5.6x2)x(200144) 2 = 1.8xl07mm4控制點AMy2 150F

9、%=廠=該Wx144 = 1.2 X10-3FF _ E _ E4ie. 一 2x5.6x200 一 2240+句 2 =(1.2xl(p3 )12'F、=1.08xl0-3Fv/fw =160解得F<148.1kAAA2240,、將力P平移至焊縫形心處，該焊縫承受剪力和扭矩的作用 、角焊縫的計算截面幾何特性2x0.7x10x100x50 + 0.7xl0x220x- AAvfTVlTVl c 0.7x10x100x2 + 0.7x10x220i220 7=x7 x 2203 + 2 x 7xl00x( + -)2 =2.425xl07mm4122 2Zv =7x220x(25.6 + -)2+2x7xl00x( -25.6)2+ x7xl003 x 2 = 3.3xl06mm4 y 2 12/=/+/ =2.425 xl0 7+3.3 xl06 = 2.755 xlO7 mm4扭矩 了 = R = 100 x IO ' x300-Xc) = 27.43*控制點A的應力t Tr 27.4x106x(100- 25.6) cr; = i 二1 P2.755 xlO7'=74N /剪