钢结构课程设计(1)

梯形屋架设计任务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（Q390）。2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（第2组，屋面雪荷载取值为：2/30.0mkN+0.1×2=2/50.0mkN）。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：2/8.106.0252.1mkN三毡四油防水层及及找平层（20mm）：2/912.002.0202.102.0182.1mkN120mm厚泡沫混凝土保温层：2/504.05.312.02.1mkN3.2可变荷载屋面雪荷载：2/7.05.04.1mkN3.3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：kNF244.3565.17.0)504.0912.08.1(4内力计算桁架杆件的内力，在单位力作用下用图解法（图2-1）求得表3-1。如图2-1表3-1杆件轴线长F荷载内力（kN）上弦杆①13580③1507-219.323④1508-219.323⑥1507-317.055⑦1508-317.055⑨1507-320.896下弦杆②2850+127.613⑤3000+280.577⑧3000+326.711斜杆a2519-229.156b2602+161.628c2859-119.159d3118+66.399e3118-24.318f3118-16.317竖杆A-B1990-17.622C-D2290-35.244E-F2590-35.244G-H2890+28.618杆件内力图5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⑨杆来选择：kNN896.320max在屋架平面内的计算长度cmlox8.150，屋架平面外的计算长度cmloy6.301。选用两个不等肢角钢6801002L，长肢水平。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）：2274.21cmAcmicmiyx61.4,40.21508.6240.28.150xoxxil7922.0x1504.6561.48.150yoyyil778.0y截面验算：22min/215/88.1934.2127778.0320896mmNfmmNAN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杆来选择：kNN711.326max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：258.1519215326711mmfNAn选择两个不等肢角钢656902，长肢水平。截面几何特点：221958.15114.17cmcmAcmix58.1cmiy42.43509.18958.1300x3509.6742.4300y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：3507.13542.4600y5.3支座竖杆AB截面选择杆轴力：kNN622.17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：2286.12cmAcmix94.1cmiy89.215010294.1199x，542.0x1509.6889.2199y，758.0y截面验算：22min/215/463.266.1228542.017622mmNfmmNAN5.4支座斜杆a截面选择杆轴力：kNN156.229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：2222.22cmAcmix20.3cmiy58.21501.792.3253x693.0x1501.9858.2253y567.0y截面验算：2min/2158.1812.2222567.0229156mmNAN5.5斜杆b截面选择杆轴力：kNN628.161计算长度：cmllox2093.2618.08.0cmloy3.261所需截面:275.751215161628cmfNAn选用两个等肢角钢5502，组成T形截面截面特性：225175.7606.9cmcmAncmix53.1cmiy38.23506.13653.1209x3508.10938.23.261y5.6竖杆CD截面选择杆轴力：kNN244.35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：2606.9cmAcmix53.1cmiy38.21507.11953.12.183x438.0x1502.9638.2229cmy580.0y截面验算：2min/21576.836.960438.035244mmNAN5.7斜杆c截面选择杆轴力：kNN159.119计算长度：cmllox1.2294.2868.08.0cmloy4.286采用两个等肢角钢5752，组成T形型截面截面几何特性：22352.3606.9cmcmAcmix53.1cmiy38.21503.9833.21.229x566.0x1502.8536.34.286y652.0y截面验算：22min/215/01.1424.1482566.0119159mmNfmmNAN5.8斜杆d截面选择杆轴力：kNN399.66计算长度：cmllox1.2294.2868.08.0cmloy4.286所需截面：28.30821566399mmfNAn采用两个等肢角钢5502，组成T形型截面截面几何特性：22088.3606.9cmcmAcmix53.1cmiy38.23507.14953.11.229x3503.12038.24.286y5.9竖杆EF截面选择杆轴力：kNN244.35计算长度：cmllox2.2072598.08.0cmloy259采用两个等肢角钢5502，组成T形截面截面几何特性：22352.3606.9cmcmAcmix53.1cmiy38.21504.13553.12.207x364.0x1508.10838.2259y501.0y截面验算：22min/215/79.1006.960364.035244mmNfmmNAN5.10斜杆e截面选择杆轴力：kNN318.24计算长度：cmllox9.2494.3128.08.0cmloy4.312采用两个等肢角钢5632，组成T形截面截面几何特性：2286.12cmAcmix94.1cmiy89.21508.12894.19.249x393.0x1501.10889.24.312y504.0y截面验算：22min/215/36.506.1228393.024318mmNfmmNAN5.11斜杆f截面选择杆轴力：kNN317.16计算长度：cmllox9.2494.3128.08.0cmloy4.312采用两个等肢角钢5632，组成T形截面截面几何特性：2286.12cmAcmix94.1cmiy89.21508.12894.19.249x393.0x1501.10889.24.312y504.0y截面验算：22min/215/79.336.1228393.016317mmNfmmNAN5.12竖杆GH截面选择杆轴力：kNN618.28计算长度：cmllox2.2312898.08.0cmloy289采用两个等肢角钢5632，组成T形截面截面几何特性：2286.12cmAcmix94.1cmiy89.23502.11994.12.231x35010089.2289y截面验算：22/215/29.236.122828618mmNfmmNAN各杆件截面选择结果列表如下表4-1屋架杆件截面选择表杆件名称计算内力（kN）计算长度（cm）截面规格截面面积（cm2）回转半径（cm）长细比容许长细比[λ]稳定系数φ计算应力（N/mm2）l0xl0yixiyλxλyλyz上弦①i0150.8301.62∠100×80×621.2742.404.6162.865.41500.7780③-219.323150.8301.62∠100×80×621.2742.404.6162.865.41500.778132.51④-219.323150.8301.62∠100×80×621.2742.404.6162.865.41500.778132.51⑥-317.055150.8301.62∠100×80×621.2742.404.6162.865.41500.778191.56⑦-317.055150.8301.62∠100×80×621.2742.404.6162.865.41500.778191.56⑨-320.896150.8301.62∠100×80×621.2742.404.6162.865.41500.778193.88下弦②+122.6133006002∠90×56×617.1141.584.42189.9135.73500.567126.35⑤+280.5773006002∠90×56×617.1171.584.42189.9135.73500.567289.14⑧+326.7113003002∠90×56×617.1141.584.42189.9135.73500.567336.68斜杆a-229.1562532532∠100×63×722.2223.202.5879.198.11500.567181.8b+161.628209261.32∠50×59.6061.532.38136.6109.83500.35948.86c-119.159229.1286.42∠75×59.6061.532.3898.385.21500.566142.01d+66.399229.1286.42∠50×59.6061.532.38149.7120.33500.30822.44e-24.318249.9312.42∠63×512.2861.942.89128.8108.11500.39350.36f-16.317249.9312.42∠63×512.2861.942.89128.8108.11500.39333.79竖杆AB-17.6221991992∠63×512.2861.942.8910268.91500.54226.463CD-35.244183.22292∠50×59.6061.532.38119.796.21500.43883.76EF-35.244207.22592∠50×59.6061.532.38135.4108.81500.364100.79GH+2