钢结构第3章作业参考答案

《钢结构》(第三版)戴国欣主编钢结构第3章作业参考答案3.1试设计双角钢与节点板的角焊接连接。钢材为Q235B，焊条为E43型，手工焊，轴心力N=1000KN（设计值），分别采用三面围焊和两面侧焊进行设计。mmhmmhmmhfff82.5125.112102.1minmax假定(1)采用三面围焊时，KNflhNwffwe3.27316022.112587.02233mmlw29816087.021035.53331KNNNaN35.53323.273100067.02131解：)(40648)(48060满足且满足mmmmhmmhffmmlmm，lmmlmml120310116810830882982121肢尖取肢背；KNNNaN35.19323.273100033.02322mmlw10816087.021035.19332＝)(40648)(48060满足且满足mmmmhmmhff(2)当采用二面侧焊时KNNaNKNNaN330100033.0670100067.02211mmfhNlwfew18416087.02103302322mmfhNlwfew37416087.02106702311)(40648)(48060满足且满足mmmmhmmhff)(40648)(48060满足且满足mmmmhmmhffmmlmm，lmmlmml20039020082184390823742121肢尖取肢背；）肢尖（对比三面围焊：肢背mmlmm，l120310213.2试求图所示连接的最大设计荷载。钢材为Q235B，焊条为E43型，手工焊，角焊缝焊脚尺寸hf=8mm,e1=30cm。解：mmx4250020522205205250087.020587.02050087.0220587.0205204423242369.2232139.21385.6020587.01220587.024250087.03.2018325020587.021250087.0cmIIIcmIcmIyxpyxFeeFTmme463)300163(16342205212＝＝－MpafwffTxVyTy16022PITTx250PIT，Ty163509687.0910FFlhFweVy22216016322.15096250PPITFIT即22216016346322.15096250463PPIFFIF222221607546922.150961115750PPIFIF2227546922.15096122.111570160PPIIFKNF53.2361069.223217546922.1509611069.2232122.11157016024242即，最大设计荷载F=236.53KN3.3试设计如图3.82所示牛腿与柱的连接角焊缝、、。钢材为Q235B，焊条为E43型，手工焊。解：查表得Mpafwt160假设焊缝mmhf8KN，FV98mKNM76.1112.098计算形心轴位置和惯性矩mmxo5.1446.520026.51386.51501006.520022006.51382126.5150＋4232218111045.142056.02122056.0245.142008.1356.045.142.211556.0cmI）－（）－（）－（mmhe6.587.0按剪力由腹板承担，弯矩由腹板和翼缘共同承担考虑MpaMpalhVwe16075.432006.5210983翼缘上边的拉应力：MpaMpaxIMf16085.4352.671018111076.1146上上腹板下口的压应力：MpaMpaxIMof16082.9348.1441018111076.1146下MpaMpaff1603.10475.430.182.932222满足要求mmhf8）然后再根据构造选取求得（注：本题也可以计算ffhh,Mpa，fwc2153.4习题3.3的连接中，如将焊缝及焊缝改为对接焊缝（按三级质量标准检验），试求该连接的最大荷载。解：若为对接焊缝，则：Mpa，fwt185Mpa，fwv125设能承受的最大集中荷载为F，VMFV12.0,mmxo43.14512200121501001220020612150形心42327.19552/2054.14202.112202.153.146.202.115cmI）（）－（当受剪时，最大剪力MpafFtISVwvx125257.541257.54)43.145206(1501212107.19554maxKNF19.231解得当在翼缘上口受拉时，KNFMpafFxIMwt9.45218557.66107.19551012.0431max解得拉当在腹板下口受压时，KNFMpafFxIMwc9.24021543.145107.19551012.043max0解得压在腹板与翼缘的交界处，剪应力与拉应力均较大，此时：FFtISV441'107.19555.908543.1452061501212107.1955）－（FFxIM44''107.19554.654843.145200107.1955120）－（拉wtf1.132'2'拉KNFFF9.2671851.1107.19555.90853107.19554.65482424KNF，19.231集中荷载该对接焊缝由剪力控制3.5焊接工字形梁在腹板上设一道拼接的对接焊缝（图3.83），拼接处作用有弯矩M=1122KN•m，剪力V=374KN，钢材为Q235B钢，焊条用E43型，半自动焊，三级检验标准，试验算该焊缝的强度。解：查表得Mpa，fwt185Mpafwv125注意：此题中腹板仍受弯剪。4321.268193121008.07.504.1282cmI(1)焊缝最大正应力在腹板和翼缘交界处MpafMpahIMwt1852.20921000101.268193101122246max焊缝正应力不满足要求(2)最大剪应力MPafMpatISVwvx1253.4825005008507142808101.2681931037443max＝(3)腹板和翼缘交界处MpatISV6.34507142808101.2681931037443''MpafMpawt1851.11.16.2176.3432.2093222'2max所以求焊缝最大剪应力满足要Mpa2.209max力不满足要求腹板和翼缘处的折算应3.6试设计图3.81所示的粗制螺栓连接，F=100KN（设计值），e1=30cm。解、现初拟采用8个M20号螺栓，其布置如下图所示：则螺栓间的最大间距dmax=8×20=160≥130mm,满足要求查表得：2305mmNfbc2140mmNfbvKNfdNbvbv96.4314042014.3422πKNftdNbcbc0.613051020校核此螺栓连接,此螺栓为承受剪、扭共同作用：2222221978)5.195.6(468cmyxiiKNyxyeFNiiTx6.29101978195.03.010042211KNyxyeFNiiTy1.910197806.03.010042211KNnFNF5.1281001KNNNNNFyx6.36)5.121.9(6.29)(22211211≤≤所以此螺栓满足要求KNNbv96.43KNNbc0.613.7试设计如图3.84所示：①角钢与连接板的螺栓连接；②竖向连接板与柱的翼缘连接；构件钢材为Q235B，螺栓为粗制螺栓，d1=d2=170mm。解：①、角钢与连接板的连接，可按照轴心受剪进行计算，选用M22号螺栓。计算所需螺栓数取n=4，其布置如下图所示7.39.93350minbNNn2/140mmNfbv2/305mmNfbc2vnmmt14KNfdnNbvvbv4.10614042214.32422πKNftdNbcbc9.933051422L1＝210≤15d0＝15X24＝360(满足)（满足）＝aanMPfMPXXAN2151.146)2481390(21035031,2/170:mmNfbt查表②、连接板与柱翼缘板的连接由于剪力由承托板承担，而力的作用线通过连接板形心，所以连接板和柱翼缘的连接应视为轴心受拉连接，拟采用C级M20螺栓。取n=6,其布置如图所示245.2cmAeKNfANbtebt7.411702459.57.4145sin350btxNNn3.73.83.8按摩擦型高强度螺栓设计习题3.7中所要求的连接（取消承托板），并分别考虑：①d1=d2=170mm;②d1=150mm,d2=190mm,螺栓强度级别及接触面用处理方式自选。解：①、选用10.9级M22号摩擦型高强度螺栓，构件选用表面喷砂处理方法，查表得：a、角钢与连接板的连接按轴心受剪计算；取:n=6，其布置如图所示45.0μKNP190KNPnNfbv95.7619045.019.09.0μ5.495.76350bvNNn（满足）＝）－（＝MPafAnnNn21590.13382413902)615.01(103505.0131b、连接板与柱翼缘板的连接，拟采用10.9级M22号螺栓4个校核此故不满足承载力要求KNNNNvt45.247707.035045sin''KNNbv95.76KNPNbt1521908.08.0KNNNvt86.61445.247121.115286.6195.7686.61bttbvvNNNN此题考虑增加螺栓数为n=6,校核其连接强度：则：满足要求，其布置如图所示KNNNvt24.41645.2471807.015224.4195.7624.41bvvbttNNNN②、当d1=150mm、d2=190mm时，角钢与连接板的连接无变化，与①相同，而连接板与柱翼缘的连接则是承受拉、弯、剪共同作用。e=0.02mKNNNNtv45.247707.035045sin''MKNeNMt702.045.247'因为弯矩较小，仍采用6个螺栓对称布置，如右图所示，则（满足）KNPKNyyMnNNitt1528.074.581.041.07645.247221'1KNNbv152KNNbt95.76KNNv24.4164