习题3.1解:①mmhmmthmmthmmthffff89~8)2~1(12102.12.1,2.55.1maxminmaxmaxmin取又沿边缘施焊,确定焊脚尺寸②计算焊缝长度⑴用三面围焊:正面角焊缝所能承受的内力为mmfhNlkNNNNkNNNNNfbhNwffwwfff29816087.0236.5337.0236.193228.273100033.0236.533228.273100067.0227328016022.112587.0227.0113223113焊缝的计算长度肢背、脂尖焊缝的内力同理,mmlmmlmmhllmmhllmmhllmmhmmlfwfwfwwfw120,310,116306829848060,648108212211212取焊缝的实际长度:满足构造要求。验算:采用两面侧焊略。习题3.398,98201962NkNMkNmm解:(1)对焊缝①的设计将力F向焊缝形心简化,maxmin,ffh14.4mmh5.2mm6,fhmm取2002618wl8mm则验算焊缝强度222620.7618820.7618862.139.6101.7/195.2/fwffNMNmmfNmm满足要求,故焊缝①可以采用6mm的焊脚尺寸焊缝2和焊缝3有效截面如图所示,设焊脚尺寸尺寸hf=8mm。求出形心位置:1345.62.825.66120.425.6186.4116.41345.625.66125.6186.473.6amma121925.65.65.612186.461b则b=136mm2322433233222212[5.66153.25.6186.412186.45.642.8]1345.670.81363136313.698120117601176010117.6/10010981046.9/25.6.4)107/==100cmbMkNmmMNmmWNmm186Nmmf(2160/Nmm134a121925.65.65.612186.461b满足要求习题3.4解:该连接为对接焊缝连接,受偏心力作用,将F向焊缝形心简化,则焊缝受V和M共同作用。其中V=F,M=Fe=120F求形心位置:1261218812y1y212118812612618812(12)266126121881218812134ymmyymm求惯性矩:34118812612(666)1881218812(134)1569.7122wIcm1261218812y1y2AB腹板焊缝截面面积2188122256wfAmm由强度计算公式求最大荷载F最大拉应力位于焊缝翼缘的上边缘A处,最大压应力位于焊缝腹板下端的B处,21412066185/3671569.710wAtwMyFfNmmFkNI3421.0210,4.43102256BBwwfMyVFFFIA折算应力:22231.11.1185203.5/wBBtfNmm由此得到:185.3FkN故该连接能承受的最大荷载为185.3KN习题3.65×1005510050400F解:选M24普通螺栓(C级),螺栓布置如图【分析:根据已知条件,牛腿与柱的螺栓连接承受由偏心力F产生的剪力和扭矩的作用。剪力V由每个螺栓平均承担;在扭矩T作用下,四个角螺栓(1、2、3、4)所受的剪力最大,且沿垂直于旋转半径r的方向受剪,为了简化计算,可将其分解为x轴和y轴方向的两个分量,1、2号螺栓的竖向分力与V产生的剪力同向,故1、2号螺栓为最危险螺栓,验算1号或2号螺栓的强度即可。】将偏心力F向螺栓群形心简化得:1234mmkNFTkNFV4104400,100查表得:22/305,/140mmNfmmNfbcbv一个螺栓的抗剪承载力设计值:kNfdnNbvvbv3.6314042414.31422一个螺栓的承压承载力设计值为:kNyxTxNkNyxTyNiiTyiiTx7.16)15050502(450100400)(50)15050502(4150100400)(22222112222211kNNNNkNNNnNNbcbvbTxTy3.63),min(9.57)()(min21211在T和V作用下,1号螺栓所受剪力最大,kNtfdNbcbc2.733051024习题3.7(1)223minmin22/215/146248139021035047.39.939.9330514224.10614042214.32422)1(mmNfmmNANNNnkNNkNftdNkNfdnNMnnbbbcbcbvvbv)(构件净截面验算个,单排布置。个,取所需螺栓数目螺栓选螺栓轴心受剪角钢与节点板的连接,解:3.7(2)个,双排布置。个,取所需螺栓数目螺栓选作用,故螺栓仅承受轴心拉力考虑承托板承担剪力,的连接竖向连接板与柱翼缘板68.45.511017003.3225.2472/2350)2(2btbtebtNNnkNfANMkNN习题3.8(2)解:①角钢与节点板的连接,选M22,8.8级螺栓,45.0接触面做喷砂处理一个螺栓的承载力设计值为:个,单排布置取所需螺栓数3,78.255.12535055.12515545.029.09.0bvfbvNNnkNPnN②竖向连接板与柱翼缘的连接,螺栓承受拉力和剪力作用kNVkNNmkNM5.247,5.24795.42/202.0350okVNnPnNkNNkNNkNyMynNNkNPkNyMynNNMifbvii4.25142.24725.1-1558(3.019.0)25.1(9.066.2128.994.3085.2709.394.303409.394.30)40120(4401095.485.2471248.02.4028.994.30)40120(41201095.485.2479.1020)2(43223222223211)各个螺栓受到的拉力为图。级高强度螺栓,排列如、选3×8050501•方法二:0.80.8155124btNPkN140.2tNkN0.90.910.4515562.8bVfNnPkN247.530.98vNkN30.940.20.82162.8124VtbbVtNNNNok习题4.3盖板不需验算构件毛截面强度验算构件净截面强度验算223223'/215/6.1781424010600)2(/215/2.2052214314240)9/35.01(10600)1(mmNfmmNANmmNfmmNANnn习题4.5提高压杆的承载力。高强度钢材并不能显著结论:对细长杆,采用钢该用、类。轴类,轴对工字钢、kNfANQkNfANililbyaxcmicmicmAyyyyxxxyx9.2083102610257.0257.07.16623534534522.1992152610355.0355.06.13789.1260,6.3957.626089.1,57.6,1.26161minminminmin002能满足要求。支撑,可在沿弱轴方向设侧向工字钢不能满足要求如轴心压力为、kNfANililmlkNyyyxxxy4.4252152610758.0758.08.6889.1130,6.3957.62603.116,3303minmin0004.83.52303.603.6044.12750224.2,7.30444.12,97,32[27.1070750,9.92215751.0101500751.07012221200412023yxyyyyyyyreqreqyilcmzcmIcmicmAacmlicmfNA确定两肢间距、选,假定由实轴选分支截面、cmbcmbbicmlixxxx3306.3244.034.14,44.034.143.527500取采用肢尖朝内,求。对虚轴的稳定性满足要验算对虚轴的稳定、,8.598.5148.1420334]26.145.487.304[2])2([2321200422111yxxxxxxxilcmicmbAIIcmcmlcmil903.93183.7581803.7551.230411101采用,—采用缀板设计、l1=90cm330cma313311128.2063.27188.0121252.28138.3907.304cmKcmaIKlIKbb两侧缀板线刚度之和:分支线刚度缀板焊缝计算、5•解:(分析:次梁简支于主梁上,依题意,次梁有整稳保证措施,选型钢梁作次梁工字钢或H型钢)①次梁的荷载及最大内力设计值板上传来的荷载:总荷载标准值与设计值:②截面最大弯矩③试选截面,根据强度条件计算截面模量选习题5.1236/,20360/kkgkNmqkNm6m0060.86066.8/1.2()1.31.26.81.36086.16/kkkkggqkNmggqkNm2max186.166387.728MkNm63387.721011911.05310xnxxMWcmf34500200812,1217,27146,651/0.64/xxHNWcmIcm.kgmkNm自重④进行相关验算:强度、刚度刚度验算:满足333985566.810611384384206102714610298250kxqlvlEI满足?整体稳定和强度是否设计值)的作用下,其括自重)撑;在集中荷载(未包中点和两端均有侧向支,梁的对称工字形,材料图示简支梁,截面为不(160235kNFBQ习题5.3(5.19)P1140.1(974.0263122.241.11037.83102061.1,2.2453.164004/215/7.14094.8177.5810113905.110981037.83104903982.0490,490256.4,53.16,1139,37.831223222'22362332mxxxExxxxxxyxxakNEANmmNfmmNWMANmkNMkNNcmicmicmWcmA类),、平面内稳定、强度、、截面几何特性解:fmmNNNWMANExxxxmxx23623'1/5.1432.833.60)26312/4908.01(10113905.110980.11037.83974.010490)8.01(习题6.1类)、平面外稳定byybtxy(636.0895.04400007.10.1,7.8756.440052okfmmNWMANxbxtxy236231/5.1881.964.92101139895.010980.11037.836