??1、计算梁自重??A?30?1?80?0.8?10?1?104cm2q?104?10?4?76.98?0.8kN/mql2Pl0.8?122160?12Mmax??G??1.2???497.3kN?m8484??2、计算中和轴位置??y1?80?0.8?40.5?10?1?81?0.5?33.2cm30?1?80?0.8?10?11IX??0.8?803?(82/2?33.2)2?80?0.8?30?1?(33.2?0.5)2?10?1?(48.8?0.5)2?93440cm12I93440WX?X??2810cm3y133.2??3、求?b??查附表3.1??b?1.751?(1?303?1?103)?2330cm412Iy2330iy???4.7cmA104?y?l1/iy?600/4.7?127.7Iy?(1?303)/12?b?I1/(I1?I2)??0.962330?b?0.8(2?b?1)?0.8?(2?0.96?1)?0.742???t??4320Ah?235y1?b??b?2??1?????b???fy?yWX??4.4h???2?2354320104?82?127.7?1???1.75????1????0.74??127.722810?4.4?82?235?????2.50.60.2820.282?b'?1.07??1.07??0.957?b2.5??4、梁整体稳定计算??M497.3?106??184.9Mpa?bWX0.957?2810?103f?215Mpa(满足)5.4解：设计习题5.1的中间主梁（焊接组合梁），包括选择截面、计算翼缘焊缝、确定腹板加劲肋的间距。钢材为Q345钢，E50型焊条（手工焊）。 解：
qk?66KN/mq?91.2KN/m
16
Fk?66?6?396KNF?91.2?6?547.2KN5V??547.2?1368KN 2M?1368?9?547.2?(6?3)?7387.2KN?mMx7387.2?106Wx???23849?103mm3rxf1.05?295（1）试选截面：
fl2295hmin????400?180001.34?106[VT]1.34?106?1585mmhe?2Wx0.4?2?(23849?103)0.4?1786mm取梁腹板高h0?1700mm1368?103tw?1.2?1.2??5.7mmhofV1700?170tw?h0/3.5?11.8mm取tw?12mmWxtwh023849?10312?1700翼缘Af?????10629mmh0617006bf?h5~h3Vmax?17005~17003?(340~567)mm取bf?500mm则tf?10629500?21.2mm取tf?24mm（2）强度验算：
17001700sx?(?12??500?24?862)?1.468?107mm3241Ix?(500?17483?488?17003)?2.27?1010mm41210Wx?Ixh2?2.27?10874?2.597?107mm3A?500?24?2?1700?12?44400mm2Mx7387.2?106????270.9MparxWx1.05?2.597?107f?295mMpafv?170Mpa
Vmaxs1368?103?1.468?107????73.7MpaIx?tw2.27?1010?12 17
（3）整稳验算：hb1?3000/500?616不需验算.
（4）刚度验算：
（5）翼缘和腹板的连接焊缝计算： （6）主梁加劲肋设计
qk?5?Fk?5?39618?110kN18m5q44v?384?klEI?5?110?(18000)510?32mm[v]?l400?18000400?45mmx3842.06?10?2.27?10hVs11368?103?(500?24?862)f?1.4Iw?1.4?2.27?1010?200?2.2mmxff取hf?8mm1.5tmax?1.524?7.3mmh0/tw?1700/12?142,80142170,宜设置横向加劲肋(?)2+?c?(?)2??1cr?c,cr?cr间距a?0.5h0?0.5?1700?850mm2h0?2?1700?3400mm取a?3000mm,设在集中荷载作用处.MI?1368?1.5?2052KN?m??mMIW?h0?2052?1062.597?107?1700?1748?76.8MpaxhI区格:vI?1368KN
?VI1368?103I?h??67.1Mpa0tw1700?12II区格:V?I?820.8KNMI??1368?4.5?547.2?1.5?5335.2??MI?hW?0h?76.8?5335.2I?2052?199.68MPax 820?8?103?I??1700?12?40.24MPaⅢ区格：V????273.6KN
18
M????1368?7.5?547.2?(4.5?1.5)?6976.8kN?m?????76.8?6976.8?261.12MPa2052 计算?cr ?cr
??273.6?103???1700?12?13.41MPah?0twfy170012345b=177?235?177?234?0.97 0.85?b1.25?cr?[1?0.75(?b?0.85)]f?[1?0.75(0.97?0.85)]?295?268.45MPaah0?30001700?1.771.0h?0twfy170012345s?415.34?4(h??02a)235415.34?4(1700?2235?1.6271.23000)?cr?1.1fv?s2?1.1?1701.6272?70.6MPa(76.8268.45)2?(67.170.6)2?0.082?0.903?0.9851
Ⅱ区格：(199.68268.45)2?(40.2470.6)2?0.553?0.325?0.8781 Ⅲ区格：(261.12268.45)2?(13.4170.6)2?0.946?0.036?0.9851
横向加劲助尺寸：
bs?h0170030?40?30?40?97mm,取140mmtbs140s?15?15?9.3mm取10mm I1140122z?12?10?1403?140?10?(2?2)?10.4?106mm43h0t3w?3?1700?123?8.8?106mm4中部支承加劲助：
区格19
Ⅰ：
70.6?1700?12?475.2kN1000A?2?140?10?360?12?7120mm21Iz??10?(140?2?12)3?2.07?107mm412Izi2??53.9mmA?2?170053.9?32??2?0.929N=1368+547.2-N475.2?103??71.8MPa?2A0.929?7120支座支承加劲助验算:547.2N?1368??1641.6kN2采用180?16板A?2?180?16?(180?100)?12?9120mm21Iz??16?(180?2?12)3?6.86?107mm4126.86?107I2??86.79120?2?170086.7?20??2?0.970Iz?AN1641.6?103??185.6MPa?A0.970?9120f?295MPafce?400MPa
f?295MPa?ce1641.6?103??366.4MPa2(180?40)?161641.6?103hf??1.8mm,用6mm?1.516?6mm4?0.7?(1700?2?50)?200第六章
6.1 有一两端铰接长度为4m的偏心受压柱子，用Q235钢的HN400×200×8×13做成，压力的设计值为490kN，两端偏心距均为20cm。试验算其承载力。 M 1 =98kN.m N=490k M1=98kN.m N=490kN
4000 20