梯形钢屋架设计

课程设计说明书第I页共I页目录1设计资料············································································································12屋架形式及几何尺寸·····························································································13支撑的布置·········································································································24荷载计算············································································································35内力计算············································································································46杆件复核············································································································57节点复核··········································································································10课程设计说明书第1页共19页采用PKPM软件进行设计，对杆件和部分节点进行手算复核。1设计资料1.1结构形式跨度为21m，总长90m，柱距6m，采用梯形钢屋架。1.2屋架尺寸及选材屋架端部高度设计为1.8m，屋面坡度为1/10，采用Q235钢，E43型焊条。1.3荷载标准值恒载有：防水层、找平层、保温层等1.7kN/m2预应力混凝土屋面板（含灌缝）1.5kN/m2屋架及支撑自重20.120.011kN/mkgL0.351kN/m2活载有：屋面均布活载0.5kN/m2雪荷载0.35kN/m2积灰荷载0.5kN/m2屋面为重屋面，不考虑风荷载；抗震设防烈度为6度，不考虑地震作用。2屋架形式及几何尺寸(1)计算跨度0215021000215020700mmLL；(2)屋架中部高度2100018000.1=2850mm2H；(3)屋架跨中起拱高度L/500=42mm，实取50mm；(4)几何尺寸如下图1所示：课程设计说明书第2页共19页1508135715081508150815081508285030003000300018152100240027002850237627092964322624552699295342ABCDEFGHIJKLM屋架几何尺寸示意图（单位：mm）图1屋架几何尺寸示意图（单位：mm）3支撑的布置根据车间长度、屋架跨度和荷载情况，上、下弦各设两道横向水平支撑，具体见支撑布置图2。CC1CC1CC2CC2CC4CC3SC1SC2SC2SC1SC1SC2SC2SC1LG2GG1GG2LG2GG1LG1LG1LG1LG1LG2GG1GG2LG2GG1LG2GG1GG2LG2GG1LG2GG1GG2LG2GG1LG2LG254006000×460006000×35400CC3CC1CC1a上弦支撑课程设计说明书第3页共19页CC3XC1XC2XC2XC1XC1XC2XC2XC1LG1LG2LG1LG1LG1LG1LG1LG1LG2LG1LG1LG2LG1LG1LG2LG11154006000×360006000×45400CC3CC1CC1CC1CC1CC2CC2CC4b下弦支撑CC1CC3CC1LG2GG2c1-1剖面垂直支撑图2屋面支撑布置（单位：mm）SC－上弦支撑；XC－下弦支撑；CC－垂直支撑；GG－刚性系杆；LG－柔性系杆4荷载计算屋面活荷载与雪荷载不同时组合，屋面活荷载大于雪荷载，故只取屋面活荷载进行计算。由于屋面坡度较小，可以将沿斜面分布的荷载均视为水平投影面上的荷载。计算时，竖向节点荷载取1.5m×6.0m面积的荷载。详见表1、表2。课程设计说明书第4页共19页表1恒载计算恒载防水层、找平层、保温层等1.7kN/m2预应力混凝土屋面板（含灌缝）1.5kN/m2屋架及支撑自重2k0.120.011kN/mgl0.351kN/m2小计3.551kN/m2表2活载计算活载屋面均布活载0.5kN/m2积灰荷载0.5kN/m2小计1kN/m2节点荷载标准值：3.5511.5631.96P恒kN，11.569P活kN5内力计算按由可变荷载效应控制的组合计算：1.231.961.40.9949.69PkN按由永久荷载效应控制的组合计算：1.3531.961.40.7951.97PkN因此计算按永久荷载效应控制的组合进行，采用PKPM软件将内力、参数输入，初步选定截面进行计算，直到PKPM计算无不符合要求的杆件。活荷载输入时应该按互斥荷载分别输入“全跨荷载”与“半跨荷载”两组数据。内力图如图3所示。课程设计说明书第5页共19页-481.4-1.3-481.5-717.9-718.0-770.4-770.4258.7616.5751.7734.6-36.3-57.2-57.2-57.21.5-467.5-267.0-105.072.3351.4173.7-13.7ABCDEFGHIJKLM杆件内力图（单位：kN）37.3图3杆件内力图（单位：kN）根据腹杆的最大设计内力467.5AGNkN，取中间节点板厚为10mm，支座节点板厚为12mm。6杆件复核Q235钢，厚度不大于16mm时，215fN/mm2，235yfN/mm26.1上弦杆图4上弦杆截面整个上弦杆采用同一种截面类型，为2L140×90×12不等边角钢短肢相并。（图4）max770.4NkN由角钢间距a=10mm查表得A=2640×2=5280mm2，xi＝2.54cm，yi＝6.81cm，压杆的容许长细比150计算长度：1508oxlmm（节点间轴线长度）yyxx10课程设计说明书第6页共19页3016oylmm（按大型屋面板与屋架保证三点焊接考虑，取oyl为两块屋面板宽）(1)刚度验算：0150859.3725.4xxxli＜150（满足）0301644.2968.1yyyli＜150（满足）因为0111400.56301611.670.5612.0612140ylbtb，所以44.29yzy＜150（满足）(2)整体稳定性验算：截面对x轴为b类，对y轴为b类，由max59.37235yf，查表得：min0.8070.37(0.8130.807)0.809因此3min770.410180.360.8095280NAN/mm2＜215fN/mm2（满足）6.2下弦杆图8下弦杆截面整个下弦杆采用同一种截面类型，为2L125×80×10不等边角钢短肢相并。（图8）max751.7NkN由角钢间距a=10mm查表得A=1970×2=3940mm2，xi＝2.26cm，yi＝6.11cm，拉杆的容许长细比350计算长度：10xxyy课程设计说明书第7页共19页1508oxlmm（节点间轴线长度），20700103502oylmm（跨中有通长细杆）(1)刚度验算：01508134.5322.6xxxli＜350（满足）010350169.3961.1yyyli＜350（满足）(2)强度验算：3751.710190.793940NAN/mm2＜215fN/mm2（满足）6.3端斜杆AG图9端斜杆截面端斜杆采用2L110×70×10不等边角钢长肢相并（图9）467.5AGNkN由角钢间距a=10mm查表得A=1720×2=3440mm2，xi＝3.48cm，yi＝2.96cm，压杆的容许长细比150计算长度：2376oxoyllmm(1)刚度验算：0237668.2834.8xxxli＜150（满足）0237680.2729.6yyyli＜150（满足）xxyy10课程设计说明书第8页共19页因为022700.48237670.4816.791070ylbtb所以442222201.091.0970(1)80.27(1)83.99237610yzyyblt＜150（满足）(2)整体稳定型验算：截面对x轴为b类，对y轴为b类，由max83.99235yf，查表得：min0.661因此3min467.510205.60.6613440NAN/mm2＜215fN/mm2（满足）6.4竖杆图10竖杆截面竖杆采用同一种截面类型（除了中竖杆，中竖杆是采用2L63×8十字型截面），选用2L63×8等边角钢，取DL杆复核。（图10）DL57.2NkN由角钢间距a=10mm查表得A=951×2=1902mm2，xi＝1.9cm，yi＝3.02cm，压杆的容许长细比150计算长度：27000.82160oxlmm，2700oylmm(1)刚度验算：xxyy10课程设计说明书第9页共19页02160113.6819xxxli＜150（满足）0270089.430.2yyyli＜150（满足）因为0630.5827007.880.5824.86863ylbtb所以44222200.4750.47563(1)89.4(1)90.8327008yzyyblt＜150（满足）(2)整体稳定型验算：截面对x轴为b类，对y轴为b类，由max90.83235yf，查表得：min0.6140.83(0.6210.614)0.62因此3min57.21048.510.621902NAN/mm2＜215fN/mm2（满足）6.5其他斜腹杆图11其他斜腹杆截面其他斜腹杆采用同一种截面类型2L80×10等边角钢，取BI杆进行复核。（图11）BI267NkN由角钢间距a=10mm查表得A=1510×2=3020mm2，xi＝2.42cm，yi＝3.74cm，压杆的容许长细比150计算长度：27090.82167.2oxlmm，2709oylmmxxyy10课程设计说明书第10页共19页(1)刚度验算：02167.289.5524.2xxxli＜150（满足）0270972.4337.4yyyli＜150（满足）因为0800.58270980.5819.641080ylbtb所以44222200.4750.47580(1)72.43(1)74.35270910yzyyblt＜150（满足）(2)整体稳定型验算：截面对x轴为b类，对y轴为b类，由max89.55235yf，查表得：min0.6210.55(0.6280.621)0.625因此3min26710141.460.6253020NAN/mm2＜215fN/mm2（满足）7节点复核Q235钢，E43型焊条，160wffN/mm27.1下弦节点B复核具体尺寸如图12所示，焊