《工業(yè)廠房鋼結(jié)構(gòu)屋架設(shè)計(jì)》計(jì)算書(shū)

)設(shè)計(jì)資料中級(jí)工作制橋式吊車，采用梯形鋼屋架，1.5×6米預(yù)應(yīng)力鋼筋混凝土大型屋面板，膨脹珍珠巖保溫層，卷材屋面，屋面坡度i=1/10。屋架采用梯形鋼桁架，其兩端簡(jiǎn)支于鋼筋混凝土柱上，混凝土標(biāo)號(hào)為C30。0002)結(jié)構(gòu)形式與布置桁架上弦支撐布置桁架下弦支撐布置垂直支撐1-1 3)荷載計(jì)算預(yù)應(yīng)力鋼筋混凝土大型屋面板卷材層找平層(厚20mm)Nm設(shè)計(jì)桁架時(shí)，應(yīng)考慮以下三種荷載組合:(1)全跨永久荷載+全跨可變荷載(2)全跨永久荷載+半跨可變荷載12(3)全跨桁架包括支撐+半跨屋面板自重+半跨屋面活荷載34(1)、(2)為使用階段荷載情況，(3)為施工階段荷載情況。4)內(nèi)力計(jì)算桁架在上述三中荷載組合作用下的計(jì)算簡(jiǎn)圖見(jiàn)圖3。由電算先解得F=1的桁架各桿件的內(nèi)力系數(shù)(F=1作用于全跨、左半跨和又半跨)。然后求出各種荷載情況下的內(nèi)力進(jìn)行組合,計(jì)算結(jié)果如下表。桿件名稱弦HIJJK內(nèi)力系數(shù)(F＝1)全跨左半跨右半跨①②③000-11.45-8.30-3.15-18.34-12.60-5.74-21.70-13.90-7.80-22.46-13.06-9.40-22.95-13.55-9.40第一種F×①0-650.59-1042.08-1233.00-1276.18-1304.02第二種組合第三種組合F1×①+F1×①+F3×①+F3×①+F2×②F2×③F4×②F4×③0000-602.96-525.09-277.02-144.00-955.29-851.57-425.78-248.58-1115.06-1022.83-477.74-320.17-1134.05-1078.71-460.20-365.66-1161.90-1099.14-475.53-368.34計(jì)算桿件0-650.59-1042.08-1233.00-1276.18-1304.02下下弦豎桿斜腹桿HgKgIKf5.26.22.32-11.3015-7.45-4.20-1.5000-0.50-1.00-1.00-1.500.45-8.350-4.85-2.0000-1.40.220-0.50-1.00-1.00-1.500.500-2.95-2.60-2.20-1.90-2.00-2.000000003.76863.67-642.079.90-423.312.51-238.64-85.2393.759-28.41-56.82-56.82-85.23019.575.62-597.46479.84-384.00278.49-205.38-56.50-8.669-28.41-56.82-56.82-85.230276.48.88947.66-515.81421.62-349.98263.37-208.40-91.28172.33.02-20.85-41.70-41.70-62.55059.53458.49473.3591.97-277.49217.95-166.03-74.630-34.52-15.65-31.30-31.30-46.950286.4743.6891.97-138.01-107.9188.20-79.803.30-57.2845.55-42.63-39.52-2.74-5.47-5.47-8.2103.76863.67-642.07 9.90-423.31 2.51-238.64 -91.28 -34.52-42.63123.99-39.52156.38 -28.41-56.82-56.82-85.23012345)桿件設(shè)計(jì)(1)上弦桿整個(gè)上弦采用等截面，按IJ、JK桿件之最大設(shè)計(jì)內(nèi)力設(shè)計(jì)。在桁架平面內(nèi)，為節(jié)間軸線長(zhǎng)度：l=150.8cm0x在桁架平面外、根據(jù)支撐布置和內(nèi)力變化情況，?。簂=3150.8cm=452.4cm因?yàn)閘=3l，估截面宜選用兩個(gè)不等肢角鋼，斷肢相并。腹桿最大內(nèi)力N=642.07kN，查表，中間節(jié)N1304020需要截面積：A===7515.7mm2f0.807215l150.8cml452.4cm需要的回轉(zhuǎn)半徑：i=0x==2.51cm，i=0y==7.54cmxy入60xyxyxi3.57x上弦截面yyxyyy(2)下弦桿N=1262.54kN=1262540N，l=300cm,l=1485cm(因跨中有通長(zhǎng)系桿)max0x0yN1262540Nnf215N/mm2Anf215N/mm2xi4.47xyi3.73yyoxxy(3)端斜桿aB0xoy0xoyxyxy斜端桿截面yxy y(4)腹桿eg一gK再分式桁架中的斜腹桿,在桁架平面內(nèi)的計(jì)算長(zhǎng)度取節(jié)點(diǎn)中心間距:l=230.1cm0x在桁架平面外的計(jì)算長(zhǎng)度l按下式計(jì)算：N39.52N39.520y1N42.6311xy=N=42630N=107.49N/mm2<215N/mm2，滿足要求。A0.3561114mm2y(5)豎桿Iex0yl255.2cmi=0xi=0yi=0y==2.13cmxyxyxyx===182.0N/mm2<215N/mm2，滿足要求。A0.3811229mm2x其余各桿的截面選擇計(jì)算過(guò)程不一一列出,結(jié)果列于表2中。桿件名稱編號(hào)計(jì)算內(nèi)力上弦IJ、JK-1304.02HgKKfgI1262.54642.076.82-423.316.82238.646.8294.28-34.5285.2342.63-39.5206.82腹桿計(jì)算長(zhǎng)度回轉(zhuǎn)半徑長(zhǎng)細(xì)比容許長(zhǎng)oxoyxyxy穩(wěn)定系數(shù)xy.6.5ii=9.6242.2447.031500.8708.7596.77169.53503.04102.5865.461500.5383.7356.7167.961500.7644.5367.5157.573502.53119.7490.511500.4404.5374.2763.331500.7243.7192.2277.063502.53135.42102.371500.3634.1389.7175.761500.6232.53163.07123.283503.04119.1895.071500.4413.71109.5291.511500.4963.04139.59111.351500.3473.04131.5104.21500.3813.29105.6137.31500.3563.29105.6137.31500.3562.45128.202002.53108.6982.173502.5383.4063.041500.665應(yīng)力06)節(jié)點(diǎn)設(shè)計(jì)采用E43型焊條，焊縫的抗拉、抗壓和抗剪強(qiáng)度設(shè)計(jì)值為fw=160N/mm2。各桿件內(nèi)力由表1查得。t(1)下弦節(jié)點(diǎn)“b”(如圖9示)設(shè)“Bb”桿的肢背和肢尖的焊縫高度h=8mm和6mm，則所需的焊縫長(zhǎng)度為：f肢背:l'=0.7Nefef圖9下弦節(jié)點(diǎn)“b”f0.7N0.7519900Nwhfwf20.78mm160N/mm2,whfwf20.78mm160N/mm2,efeff根據(jù)上面求得的焊縫長(zhǎng)度，并考慮桿件之間應(yīng)有的間隙以及制作和裝配等誤差，按比例繪出節(jié)點(diǎn)詳下弦與節(jié)點(diǎn)板連接待焊縫長(zhǎng)度為46cm,h=6mm。焊縫所受的力為左右兩下弦桿的內(nèi)力差fT==T==103.6N/mm2160N/mm2，焊縫滿足強(qiáng)度要求。f20.76mm(460mm12mm)(2)上弦節(jié)點(diǎn)“B”(如圖10示)(0(0.75650590N)2+()2(0.25650590N)2+()2fw2hfwf20.710mm160N/mm2,fw2hfwf20.710mm160N/mm2,effw2hfwf20.78mm160N/mm2fw2hfwf20.78mm160N/mm2ef為了便于在上弦上擱置屋面板，節(jié)點(diǎn)板的上邊緣可縮進(jìn)上弦肢背8mm。用槽焊縫把上弦角鋼和節(jié)點(diǎn)板連接起來(lái)。槽焊縫作為兩條角焊縫計(jì)算，焊縫強(qiáng)度設(shè)計(jì)值乘以0.8的折減系數(shù)。計(jì)算時(shí)可略去桁架上弦坡度的影響，而假定集中荷載F與上弦垂直。上弦肢背槽焊縫內(nèi)的應(yīng)力為：1h'=節(jié)點(diǎn)板厚度=12mm=6mm,f22f[K(NN)]2+(F)2=hl20.76(50512)fwt[K(NN)]2+(F)2=fwt此節(jié)點(diǎn)亦可按另一種方法驗(yàn)算。節(jié)點(diǎn)荷載由槽焊縫承受，上弦兩相鄰節(jié)間內(nèi)力差由角鋼肢尖焊縫承6MM==6MM==MTN2+(f)2=受，這時(shí)槽焊縫肯定是安全的，可不必驗(yàn)算。肢尖焊縫驗(yàn)算如下：(3)屋脊節(jié)點(diǎn)“K”(如圖11示)節(jié)點(diǎn)“K”弦桿一般都采用同號(hào)角鋼進(jìn)行拼接角鋼與弦桿肢尖能夠密合，并便于施焊，需將拼接角鋼的尖角削除，且截去垂直肢的一部分寬度(一般為t+h+5mm)。拼接角鋼的這部分削弱，可以考節(jié)點(diǎn)板來(lái)補(bǔ)償。f接頭一邊的焊縫長(zhǎng)度按弦桿內(nèi)力計(jì)算。設(shè)焊縫h=10mm，則所需焊縫計(jì)算長(zhǎng)度為(一條焊縫)：f上弦與節(jié)點(diǎn)板之間的槽焊，假定承受節(jié)點(diǎn)荷載，驗(yàn)算略.上弦肢尖與節(jié)點(diǎn)板的連接焊縫,應(yīng)按上弦內(nèi)力的15%計(jì)算.設(shè)肢尖焊縫h=10mm,節(jié)點(diǎn)板長(zhǎng)度為60cm,則節(jié)點(diǎn)一側(cè)弦桿焊縫的計(jì)算長(zhǎng)度為f60cmlw=一1cm一2cm=27cm,焊縫應(yīng)力為:2fmm2702mm2因桁架的跨度較大,需將桁架分成兩個(gè)運(yùn)輸單元,在屋脊節(jié)點(diǎn)和下弦跨中節(jié)點(diǎn)和下弦跨中節(jié)點(diǎn)設(shè)置工地拼接,左半邊上網(wǎng)上弦,斜桿和豎桿與節(jié)點(diǎn)板連接用工廠焊縫,而右半邊的上弦,斜弦與節(jié)點(diǎn)板的連接用工地焊縫.腹桿與節(jié)點(diǎn)板連接焊縫計(jì)算方法與以上幾個(gè)節(jié)點(diǎn)相同(4)支座節(jié)點(diǎn)“a”(如圖示)①支座底板的計(jì)算驗(yàn)算柱頂混凝土的抗壓強(qiáng)度:===8.67N/mm2f=14.3N/mmA65520mm2cnf為混凝土強(qiáng)度設(shè)計(jì)值，對(duì)于C30混凝土，f=14.3N/mm2。cc底板的厚度按桁架反力作用下的彎矩計(jì)算,節(jié)點(diǎn)板和加勁肋