1、钢结构设计原理课程设计淮 阴 工 学 院课程设计计算书 课程名称: 钢结构设计原理 设计题目: 某梯形钢屋架设计 专业层次: 土木工程(专转本)班 级: 土木 3132 * * * 学 号: * * * 2 0 16年 6月一设计资料1)某厂房跨度为21m,总长90m,柱距6m,屋架下弦标高为18m。2)屋架铰支于钢筋混凝土柱顶,上45柱截面400400,混凝土强度等级为C30。3)屋面采用1.56m的预应力钢筋混凝土大型屋面板。(屋面板不考虑作为支撑用)。4)该车间所属地区为南京市5)采用梯形钢屋架,考虑静载:预应力钢筋混凝土屋面板(包括嵌缝)、二毡三油加绿豆沙、找平层2cm厚、支撑重量;考
2、虑活载:活载6)钢材选用Q235钢,焊条为E43型。二、屋架形式和几何尺寸屋面材料为大型屋面板,故采用无檩体系平破梯形屋架。屋面坡度i=(30401990)/10500=1/10;屋架计算跨度L02100030020700mm;端部高度取H=1990mm,中部高度取H=3040mm(约l/6.8)。屋架几何尺寸如图1所示:图1:21米跨屋架几何尺寸三、支撑布置由于房屋长度有90米,故在房屋两端及中间设置上、下横向水平支撑和屋架两端及跨中三处设置垂直支撑。其他屋架则在垂直支撑处分别于上、下弦设置三道系杆,其中屋脊和两支座处为刚性系杆,其余三道为柔性系杆。(如图2所示) 设计屋架荷载一屋架节点荷载
3、屋架坡度较小,故对所有荷载均按水平投影面计算,风荷载为吸力,不与考虑静载 1)预应力钢筋混凝土面板 1.4KN/ 2)二毡三油加绿豆沙 0.4 KN/ 3)找平层2cm厚 0.4 KN/ 4) 支撑重量 0.07 KN/ 5)屋架自重 0.12+0.011L=0.12+0.01121=0.351 KN/ =2.621 KN/ 活载+积灰荷载 1.5 KN/ 荷载组合按全跨永久荷载和全跨可变荷载,按下式计算,其他组合内力计算结果见附表1所示;对跨中部分斜腹杆因半跨荷载可能产生的内力变号,采取将跨度中央每侧各三根斜腹杆(图1中Fg、gH、Fe)均按压杆控制长细比,150,故不再考虑半跨荷载作用的组
4、合。计算屋架时考虑下列三种荷载组合情况1)全跨静荷载+全跨或荷载a可变荷载效应组合的计算:取永久荷载 G=1.2,屋面活载 Q1.4则永久荷载设计值P 1.22.6213.1452KN/ ;可变荷载设计值P 1.41.52.1 KN/ ;节点荷载设计值P (3.14522.1)1.5647.2086KNb永久荷载效应组合计算:取永久荷载G1.35,屋面活载Q1.4, =0.7,则永久荷载设计值P 1.352.6213.538KN/ 可变荷载设计值P 1.40.71.5=1.47 KN/ 节点荷载设计值P (3.5381.47)1.5645.07KN所以:P 47.208KN P 45.07KN
5、故取节点荷载设计值P47.208KN 2)计算全跨永久荷载半跨可变荷载a可变荷载效应组合P 1.22.6211.5628.30KNP 1.51.41.5618.9KNP = P + P =28.30+18.9=47.20KNb永久荷载效应组合P =1.352.6211.56=31.85KN P =1.40.71.51.5613.23KNP =45.50KN所以取按可变荷载效应组合计算3)半跨屋面板荷载半跨活载全跨屋架自重a可变荷载效应组合P 1.20.3511.563.79KNP (1.21.4+1.41.5)1.5634.02KN P =37.81 KNb永久荷载效应组合P 1.350.35
6、11.56=4.25 KNP (1.351.4+1.40.71.5)1.56=30.24 KNP =34.49 KN所以取按可变荷载效应组合计算综上,荷载情况如下:1)满载:屋架上弦节点荷载P47.208KN2)全跨永久荷载半跨可变荷载P全 31.85KN P 半18.9KN3)半跨屋面板荷载半跨活载全跨屋架自重P全 3.79 KN P半 34.02KN二屋架杆件内力计算用图解法先求出全垮和半跨单位节点荷载作用下的杆件内力系数,然后乘以实际的节点荷载,屋架在上述第一种荷载组合作用下,屋架的弦杆、竖杆和靠近两端的斜腹杆,内力均达到最大,在第二种和第三种荷载作用下,靠跨中的斜腹杆的内力可能达到最大
7、或发生变号。因此,在全垮荷载作用下所有杆件的内力均应计算,而在半跨荷载作用下仅需计算靠近跨中的斜腹杆内力。计算结果列于下表:杆件名称杆内力系数 全跨永久荷载 全跨可变荷载 P全47.208KN 全跨永久荷载 半跨可变荷载 P全31.85KN P半18.9KN 全跨屋架支撑 半跨屋面板 半跨可变荷载 P全3.79 KN P半34.02KN计算内力P1左半跨 (1)右半跨 (2) 全跨 (3)N=P全(3)左右左右上弦杆AB0000 0 0 0.00 0.00 0 BD-5.31-2.162-7.472-433.43 -392.57-333.07 -208.96 -101.87 -433.43 D
8、F-7.339-3.923-11.262-653.27 -579.13 -514.57 -292.36 -223.64 -653.27 FH-6.861-5.319-12.18-706.52 -605.99 -576.85 -279.57 -227.11 -706.52 下弦杆ac3.011.094.1237.83 217.23 180.94117.94 52.62 237.83 ce6.6633.0819.744565.22 506.99 439.29 263.61 131.75 565.22 eg7.3264.63611.962693.88 606.26 555.42 294.57 203
9、.05 693.88 gh5.8845.88411.768682.62 571.42 571.42 244.78 244.78 682.62 腹 杆aB-5.641-2.043-7.684-445.72 -407.11 -339.11 -221.03 -98.63 -445.72 Bc3.961.8485.808336.90 301.98 262.06 156.73 84.88 336.90 cD-2.633-1.776-4.409-255.75 -222.19 -205.99 -106.29 -77.13 -255.75 De1.2221.572.792161.95 132.28 138.8
10、6 52.15 63.99 161.95 eF-0.047-1.525-1.572-91.19 -62.36-90.30 -7.56 -57.84 -91.19 Fg-1.0391.3670.32819.03 -6.81 38.66 -34.10 47.75 19.03 gH1.913-1.20.71341.36 64.045.2067.78 -38.12 41.36 竖杆Aa-0.50-0.5-29.00 -29.00 -19.55 -18.91 -1.90 -29.00 Cc-10-1-58.01 -58.01 -39.11 -37.81 -3.79 -58.01 Ee-10-1-58.0
11、1 -58.01 -39.11 -37.81 -3.79 -58.01 Gg-10-1-58.01 -58.01 -39.11 -37.81 -3.79 -58.01 三杆件截面选择按腹杆最大内力Nab=-445.72KN,查表7.6,选中间节点板厚度为10mm,支座节点板厚度12mm。上弦杆整个上弦杆不改变界面,按最大内力计算,NFH=-706.52KN,l0x=150.75cm,l0y =301.5cm(取等于两层屋面板宽)。截面宜选用两个不等肢角钢,短肢-706.52KN相并。 查附表5.2:0.688Areq=N /f=706.52103 /(0.688315102)= 32.60cm
12、2假定80 ixreq=l0x /150.75 / 80=1.88cm iyreq=l0y /301.5 /80=3.77cm由表6.10选2 1409014短肢相并,A230.46=60.91cm2,ix=2.511cm,iy=6.78cm,截面验算: x=l0x / ix=150.75 /2.511=60.04 150 (满足)y=l0y / iy= 301.5/6.78=44.47 150 (满足)双角钢T形截面绕对称轴(y轴)应按弯矩扭曲计算换算长细比yzb1 / t=110/10=110.56 l0y / b1=0.56301.5 /11=15.35 故 yz=y =44.47x=6
13、0.04故由max=x =60.04,查附表4.2,得0.807N /A=706.52103 /( 0.80760.91102)143.73N/mm2f=215 N/mm2(满足)垫板每节间放置一块(满足l1范围内不少于两块),ld150.75/275.4cm40i403.48139.2cm(i为3.48cm)。下弦杆整个下弦采用等截面。按最大内力Neg=+693.88kN计算长度l0x=300cm,l0y=885cm。Anreq=N / f =693.88103 /215 =3227.35mm2=32.27cm2由附录8 P433 2L1008010,短肢相并,A=217.167=34.33
14、4 cm2,ix=2.348cm,iy=8.05cm=N/An=693.88103/34.33102=202.12N/mm2f=215 N/mm2(满足)x=l0x / ix=300 / 2.348 =127.77 350 (满足)y=l0y / iy=885 /8.05=109.94 350 (满足)垫板每节间放置一块,ld300/2=150cm80i803.32256cm(i为3.32cm)端斜杆 1BA杆Nba=-445.72kN,l0x l0y253cm,选用 2L1107010,长肢相并,查附表8,A=217.167=34.33cm2,ix=3.48cm,iy=3.04cmx=l0x
15、 / ix=253 /3.48=72.7 150 (满足)y=l0y / iy=253 /3.04=83.4 150 (满足)因为b2/t=10x,故由yz查附表1.2得x=0.648。N/A=445.72103/(0.64834.33102)=200.36 N/mm2 f=215 N/mm2(满足)110*70*10设两块垫板,ld253/3=84.3cm40i402.2891.2cm(i为2.28cm)。斜腹杆 Bc杆NBc=+336.90kN,l0x 0.8L=0.8261.3209.04cm,l0yL=261.3cm,选用2L708。查附表6.9,A=210.7=21.4 cm2,ix
16、2.12cm,iy=3.23cmx=l0x / ix=209.04 /2.12 =98.6 350 (满足)y=l0y / iy=261.3 /3.23=80.9 350 (满足)=N/An=336.90103/21.4102=157.43N/mm2f=215 N/mm2(满足) 设两块垫板,ld209.04/3=69.6840i403.23129.2cm(i为3.23cm)2Fg杆最大拉力NFg=+47.75 kN,最大压力NFg=34.10 kNl0x 0.8L=0.8312.4249.92cm,l0y312.4cm.选用2 635,查附表6.9,A26.14=12.28 cm2,ix1.
17、94cm,iy=2.89cmx=l0x / ix=249.92 /1.94 =128.82 150 (满足)y=l0y / iy=312.4 / 2.89= 108.1 150 (满足)x=0.396y=0.505N /A=47.75103 /( 0.39612.28102)98.19 N/mm2f=215 N/mm2(满足)设三块垫板,ld249.92/4=62.4840i402.89115.6cm(i为2.89cm) gH杆NgH=67.78KN,l0x 0.8l=0.8339271.2cm,l0y339cm.内力较小,故选用2 635,查附表6.9,A26.14=12.28cm2,ix1
18、.94cm,iy=2.89cmx=l0x / ix=271.2 /1.94 =139.79 150 (满足)y=l0y / iy=312.4 / 2.89= 117.3 150 (满足)x =0.353y=0.449N /A=67.78103 / (0.35312.28102)156.36 N/mm2f=215 N/mm2(满足)设三块垫板,ld271.2/4=67.840i402.89=115.6cm(i为2.89cm)Fe杆 NFe=-91.19KN,l0x=0.8312.4=249.92cm, l0y312.4cm选用2 635,查附表6.9,A26.14=12.28cm2,ix1.94
19、cm,iy=2.89cm x=l0x / ix=249.92/1.94=128.82 150 (满足)y=l0y / iy= 312.4/2.89=108.1 150 (满足)x=0.396y=0.505N /A=91.19103/(0.39612.28102)=187.52N/mm2f=215 N/mm2(满足)设三块垫板,ld249.924/4=62.4840i402.89115.6cm(i为2.89cm)竖杆1Gg杆NGg=-58.01kN, l0x 0.8289231.2cm,l0y289cm.同理,故宜按压杆的容许长细比进行控制。现选用2 635,A25.42=10.84cm,查附表
20、6.9,A26.14=12.28cm2,ix1.94cm,iy=2.89cmx=l0x / ix=231.2 /1.94=119.2 150 (满足)y=l0y / iy=289 / 2.89= 100 150 (满足)x=0.441y=0.555N /A=58.01103/(0.44112.28102)=107.12N/mm2f=215 N/mm2(满足)设三块垫板,ld231.2/4=57.840i402.89115.6cm(i为2.89cm)Aa杆NAa=-29.00 KN, l0x l0y=199cm, 选用2 635,A25.42=10.84cm查附表6.9,A26.14=12.28
21、cm2,ix1.94cm,iy=2.89cmx=l0x / ix=199/1.94=102.6 150 (满足)y=l0y / iy=199/2.89=68.9 150 (满足)x=0.54y=0.757N /A=29.00103 /(0.5412.28102)=43.73 N/mm2f=215 N/mm2(满足)设两块垫板,ld199/3=66.340i402.89115.6cm(i为2.89cm)其他杆截面见下表,选用时一般腹杆按2 708,竖杆选2 635 不等肢角钢长肢相并的T型截面,腹杆采用两个等肢角钢组成的T型截面屋架杆件截面选择表杆件 名称内力(kN)计算长度(cm)截面形式和规
22、格截面面积(cm2)回转半径(cm)长细比容许长细比稳定系数min计算应力(N/mm2)l0xl0yixiyxy yz上弦杆AI-706.52150.75301.52L140901460.912.516.7860.0444.471500.807143.73下弦ai+693.883008852L100801034.332.358.05127.77109.94350202.12斜杆aB-445.72 2532532L110701034.333.483.0472.783.41500.648200.36Bc+336.90 209.04261.32L70821.42.123.2398.6180.9350
23、157.43Dc-255.75 229.12286.42L70821.42.123.23108.188.71500.505236.65De161.95229.12286.42L70821.42.123.23108.188.735075.68eF-91.19 249.92312.42L63512.281.942.89128.8108.11500.396187.52Fg-34.10 (47.75)249.92312.42L63512.281.942.89128.8108.11500.396(98.19)gH67.78271.23392L63512.281.942.89139.8117.31500.
24、353156.36竖杆Aa-29.00 199 1992L63512.281.942.89102.668.91500.54043.73Cc-58.01 183.2 2292L63512.281.942.89119.796.21500.441107.12Ee-58.01 207.2 2592L63512.281.942.89106.386.91500.51591.73Gg-58.01 231.22892L63512.281.942.89119.21001500.441107.12注:上弦杆和下弦杆采用的是不等肢角钢短肢相并的T型截面形式,支座斜杆杆采用的是节点设计在确定节点板的形状和尺寸时,需要
25、斜腹杆与节点板间连接焊缝的长度。先算出各腹杆杆端需要的焊缝尺寸。其计算公式为:角钢肢背所需焊缝长度:角钢肢尖所需焊缝长度:如腹杆aB,设计杆力N-445.72kN,设肢背与肢尖的焊脚尺寸各为hf18mm,hf26mm。因aB杆系不等边,角钢与长肢相连,故K12/3,K21/3。则:l1(0.667445.72103)/(20.78160)+28=181.9mm 取l1190mml2(0.333445.72103)/(20.76160)+12=122.4,取l2130mm其它腹杆所需焊缝长度的计算结果见下表。未列入表中的腹杆均因杆力很小,可按构造取 肢尖: hfmm,l18hf+1085+105
26、0 mm肢背:hf6mm, l260mm腹杆焊缝尺寸:杆件 名称设计内力(kN)肢背焊缝肢尖焊缝l1(mm)hf(mm)l2(mm)hf(mm)aB-445.72 1908130 6Bc274.18 150 61005cD-208.13 120680 5De131.80806505表中1l、12为取整后数值,1、下弦节点“c”按表3所列Bc、cD杆所需焊缝长度,按比例绘制节点详图,从而确定节点板的形状和尺寸。由图中量出下弦与节点板的焊缝长度为325mm,焊脚尺寸hf6mm,焊缝承受节点左、右弦杆的内力差NNbc-Nab459.98-193.55266.43 kN。验算肢背焊缝的强度:fK1N/(20.7helw)=(0.667266.43103)/20.76(325-12)=67.59N/mm2fwf=160N/mm2(满足)2下弦结点“e”按表3所列De、Fe杆所需焊缝长度,按比例绘制节点详图,从而确定节点板的形状和尺寸。由图中量出下弦与节点板的焊缝长度为300mm,焊脚尺寸hf6mm,焊缝承受节点
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1