1钢结构课程设计学号姓名学校专业梯形屋架设计1设计资料梯形屋架,建筑跨度为18m,端部高度为1.99m,跨中高度为2.89m,屋架坡度i=1/10,屋架间距为6m,屋架两端支撑在钢筋混凝土柱上,上柱截面400mm×400mm,混凝土采用20C。屋架上、下弦布置有水平支撑和竖向支撑(如图1-1所示)。屋面采用1.5×6m预应力钢筋混凝土大型屋面板,120mm厚珍珠岩(3/350mkgr)的保温层,三毡四油铺绿豆沙防水层,20mm厚水泥砂浆找平层,屋面雪荷载为2/30.0mkN,钢材采用3号钢。22设计要求2.1屋面雪荷载取值:按分组序号,取用设计资料屋面雪荷载+0.1×分组序号(比如第1组,屋面雪荷载取值为:2/30.0mkN+0.1×1=2/40.0mkN,以此类推)。2.2设计中,应绘制出必要的节点详图等图纸。2.3其他条件与设计资料相同。3荷载计算3.1永久荷载预应力钢筋混凝土大型屋面板:2/68.14.12.1mkN三毡四油防水层及及找平层(20mm):2/912.076.02.1mkN120mm厚泡沫混凝土保温层:2/504.042.02.1mkN屋架自重和支撑自重按经验公式(跨度l=18m)2/32181.12.11.12.1mkglPw2/384.032.02.1mkN3.2可变荷载3屋面雪荷载:2/77.055.04.1mkN3.3荷载组合永久荷载可变荷载为主要荷载组合,屋架上弦节点荷载为:kNF25.3865.177.0)384.0504.0912.068.1(4内力计算桁架杆件的内力,在单位力作用下用图解法求得表4-1。杆件轴线单位荷载内力F荷载内力(kN)上弦杆B-①135700C-③1508-6.223-238.030D-④1507-6.223-238.030E-⑥1508-8.996-344.097F-⑦1507-8.996-344.097G-⑨1508-9.105-348.266下弦杆②-O2850+3.479+133.072⑤-O3000+7.961+304.508⑧-O3000+9.270+354.578斜杆①-②2530-6.502-248.702②-③2613+4.586+175.415④-⑤2864+3.381-129.323⑤-⑥3124+1.884+72.063⑦-⑧3124-0.690-26.393⑧-⑨3124-0.463-17.710竖杆A-①1990-0.500-19.125③-④2290-1.000-38.250⑥-⑦2590-1.000-38.250⑨-⑩2890+0.812+31.0595截面选择5.1上弦杆截面选择上弦杆采用相同截面,以最大轴力G-⑨杆来选择:kNN266.348max在屋架平面内的计算长度cmlox8.150,屋架平面外的计算长度cmloy5.301。选用两个不等肢角钢6801002L,长肢水平。4截面几何特性(长肢水平双角钢组成T形截面,节点板根据腹杆最大内力选用板厚8mm):2274.21cmAcmicmiyx61.4,40.21508.6240.28.150xoxxil7922.0x1504.6561.48.150yoyyil778.0y截面验算:22min/215/4.2104.2127778.0348266mmNfmmNAN大型屋面板与上弦焊牢,起纵横向水平支撑作用,上弦杆其他节间的长细比和稳定验算均未超过上述值。5.2下弦杆截面选择下弦杆也采用相同截面,以最大轴力⑧-O杆来选择:kNN578.354max在屋架平面内的计算长度:cmlox300,屋架平面外的计算长度:cmloy300。所需截面面积为:24.1649215354578mmfNAn选择两个不等肢角钢656902,长肢水平。截面几何特点:22494.16114.17cmcmAcmix58.1cmiy42.43509.18958.1300x3509.6742.4300y另两个节点的下弦杆内力较小,但cmloy600,故须验算其屋架平面外的长细比:3507.13542.4600y5.3支座竖杆截面选择杆轴力:kNN125.19计算长度:cmlloyox199,采用两个等肢角钢5632,组成T型截面截面几何特性:2286.12cmAcmix94.1cmiy89.215010294.1199x,542.0x1509.6889.2199y,758.0y5截面验算:22min/215/720.286.1228542.019125mmNfmmNAN5.4支座斜杆截面选择杆轴力:kNN702.248计算长度:cmlloyox253采用两个不等肢角钢7631002,长肢相拼。截面几何特性:2222.22cmAcmix20.3cmiy58.21501.792.3253x693.0x1501.9858.2253y567.0y截面验算:2min/2154.1972.2222567.0248702mmNAN5.5斜杆②③截面选择杆轴力:kNN415.175计算长度:cmllox2093.2618.08.0cmloy3.261所需截面:288.815215175415cmfNAn选用两个等肢角钢5502,组成T形截面截面特性:221071.8606.9cmcmAncmix53.1cmiy38.23506.13653.1209x3508.10938.23.261y5.6竖杆③④截面选择杆轴力:kNN250.38计算长度:cmllox2.1832298.08.0.cmloy229采用两个等肢角钢5502,组成T形截面。截面几何特性:2606.9cmAcmix53.1cmiy38.21507.11953.12.183x438.0x1502.9638.2229cmy580.0y截面验算:2min/21591.906.960438.038250mmNAN5.7斜杆④⑤截面选择6杆轴力:kNN323.129计算长度:cmllox1.2294.2868.08.0cmloy4.286采用两个等肢角钢5752,组成T形型截面截面几何特性:22352.3606.9cmcmAcmix53.1cmiy38.21503.9833.21.229x566.0x1502.8536.34.286y652.0y截面验算:22min/215/1.1544.1482566.0129323mmNfmmNAN5.8斜杆⑤⑥截面选择杆轴力:kNN063.72计算长度:cmllox1.2294.2868.08.0cmloy4.286所需截面:22.33521572063mmfNAn采用两个等肢角钢5502,组成T形型截面截面几何特性:22352.3606.9cmcmAcmix53.1cmiy38.23507.14953.11.229x3503.12038.24.286y5.9竖杆⑥⑦截面选择杆轴力:kNN250.38计算长度:cmllox2.2072598.08.0cmloy259采用两个等肢角钢5502,组成T形截面截面几何特性:22352.3606.9cmcmAcmix53.1cmiy38.21504.13553.12.207x364.0x1508.10838.2259y501.0y截面验算:22min/215/4.1096.960364.038250mmNfmmNAN5.10斜杆⑦⑧截面选择杆轴力:kNN393.26计算长度:cmllox9.2494.3128.08.0cmloy4.312采用两个等肢角钢5632,组成T形截面7截面几何特性:2286.12cmAcmix94.1cmiy89.21508.12894.19.249x393.0x1501.10889.24.312y504.0y截面验算:22min/215/7.546.1228393.026393mmNfmmNAN5.11斜杆⑧⑨截面选择杆轴力:kNN710.17计算长度:cmllox9.2494.3128.08.0cmloy4.312采用两个等肢角钢5632,组成T形截面截面几何特性:2286.12cmAcmix94.1cmiy89.21508.12894.19.249x393.0x1501.10889.24.312y504.0y截面验算:22min/215/7.366.1228393.017710mmNfmmNAN5.12竖杆⑨⑩截面选择杆轴力:kNN059.31计算长度:cmllox2.2312898.08.0cmloy289采用两个等肢角钢5632,组成T形截面截面几何特性:2286.12cmAcmix94.1cmiy89.23502.11994.12.231x35010089.2289y截面验算:22/215/3.256.122831059mmNfmmNAN各杆件截面选择结果列表如下表5-1杆件计算内力(kN)截面规格截面面积(2cm)计算长度(cm)迴转半径(cm)长细比容许长细比稳定系数应力N/mm2名称编号上炫杆Fg-gh-735.399125*1048.746150.7301.53.855.5239.254.61500.833181.1下炫杆gi729.964100*80*1034.3343003002.354.78127.6662.76350/212.6腹杆Aa-23.22445*35.3181901901.402.30135.782.61500.362120.6腹杆aB-418.025100*831.2762442443.084.5679.353.61500.692193.18腹杆Bc322.57680*315.824202.25252382.463.6381.56906350203.9腹杆Cc-46.44745*46.972174.8218.51.382.24126.797.51500.403165.3腹杆cD-253.41675*823.01222.0277.52.283.0597.3779.291500.572192.4腹杆De170.92645*58.584222.0277.51.372.26162.0122.8350199.16节点设计各节点的节点板厚一律取8mm。6.1下弦节点i设计首先,计算腹杆与节点板连接焊缝尺寸,然后按比例绘出节点板形状和尺寸,最后验算下弦与节点板的连接焊缝。已知焊缝的抗拉、抗压和抗剪的强度设计值:2/160mmNffw设杆②③的肢背和肢尖焊缝分别是mmhf6和mmhf5,则所需焊缝长度为:肢背:mmhefNlwfw4.9116067.021754157.027.0/取110mm肢尖:mmhefNlwfw0.5016057.021754157.027.0//取80mm设杆④⑤的肢背和肢尖焊缝分别是mmhf6和mmhf5,则所需焊缝长度为肢背:mmhefNlwfw4.6716067.021293237.027.0/取100mm肢尖:mmhefNlwfw6.3416057.021293237.027.0//取80mm设杆③④的肢背和肢尖焊缝均为mmhf5,则所需焊缝长度为肢背:mmhefNlwfw9.2316057.02382507.027.0/