钢结构设计基本原理课后答案 肖亚明

合肥工业大学出版社出版（肖亚明主编）第三章1.解：Q235钢、2/160mmNfwf、kNN600（1）采用侧面角焊缝最小焊脚尺寸：mmthf6.5145.15.1max角钢肢背处最大焊脚尺寸：mmthf12102.12.1min角钢肢尖处最大焊脚尺寸：mmthf8~9)2~1(10)2~1(角钢肢尖和肢背都取mmhf8查表3-2得：65.01K、35.02KkNNKN39060065.011，kNNKN21060035.022所需焊缝计算长度：mmfhNlwffw63.21716087.02103907.02311mmfhNlwffw19.11716087.02102107.02322焊缝的实际长度为：mmhllfw63.2338263.217211，取240mm。mmhllfw19.1338219.117222，取140mm。（2）采用三面围焊缝，取mmhf6正面角焊缝承担的内力为：kNflhNwffwf97.16316022.1100267.07.033侧面角焊缝承担的内力为：kNNNKN01.3082/97.16360065.02/311kNNNKN02.1282/97.16360035.02/322所需焊缝计算长度：mmfhNlwffw17.22916067.021001.3087.02311mmfhNlwffw25.9516067.021002.1287.02322焊缝的实际长度为：mmhllfw17.235617.22911，取240mm。mmhllfw25.101625.9522，取110mm。2.解：Q235钢、2/160mmNfwf（1）取mmdd17021角焊缝受到轴力和剪力的共同作用，且均作用在角焊缝形心处角焊缝受到轴力为：kNN23.49915.15.160022角焊缝受到剪力为：kNV82.33215.1160022ffwhhl23402170223/2.19516022.1)2340(4.11023.4997.02mmNfhhlhNwffffwff由上式求得：mmhf55.523/160)2340(4.11082.3327.02mmNfhhlhVwfffwff由上式求得：mmhf49.4最小焊脚尺寸mmthf71.6205.15.1max故取焊脚尺寸为mmhf7223/2.195/26.156)72340(74.11023.4997.02mmNfmmNlhNwffwff23/16018.104)72340(74.11082.3327.02mmNflhVwfwff222222/160/10.16518.10422.1/26.156/mmNfmmNwffff由于折算应力较接近wff，故取mmhf8可满足要求。（2）改取mmd1501，mmd1902角焊缝受到轴力、剪力和弯矩的共同作用角焊缝受到轴力为：kNN23.49915.15.160022角焊缝受到剪力为：kNV82.33215.1160022角焊缝受到弯矩为：mmNmmkNNeM6109846.96.99842023.499mmhe6.587.0，mmhlfw3248234021901504631074.31123246.52mmIw3361096.1953241074.3123242mmI最大正应力为：22363/2.19516022.1/53.1881096.195109846.932487.021023.4997.02mmNmmNWMlhNwwff23/16072.9132487.021082.3327.02mmNflhVwfwff222222/160/70.17972.9122.1/53.188/mmNfmmNwffff不满足要求。3.解：Q235钢、2/160mmNfwf（1）角焊缝①最小焊脚尺寸：mmthf2.5125.15.1max最大焊脚尺寸：mmthf4.14122.12.1min取mmhf6xx角焊缝①受到轴力和弯矩的共同作用角焊缝受到轴力为：kNFN100角焊缝受到弯矩为：mkNNeM220100mmhe2.467.0，mmhlfw1886220022004631065.4121882.42mmIw3361048.491881065.421882mmI最大正应力为：22363/2.19516022.1/74.1031048.4910218867.02101007.02mmNmmNWMlhNwwff满足要求。（2）角焊缝②③角焊缝的有效截面如图所示取mmhf8角焊缝有效截面形心位置：mmyy03.136)6.519226.54.5526.5134/(]2/1926.51922)8.2192(6.54.552)8.212192(6.5134[2剪力由腹板焊缝承担，腹板面积为：24.21506.51922mmAw全部焊缝对x轴的惯性矩为：4632221056.1512/1926.52)2/19203.136(6.51922)8.203.136192(6.54.552)8.21203.136192(6.5134mmIw翼缘焊缝最外边缘的截面模量：346111015.216.51203.1361921056.15mmhI翼缘和腹板连接处的截面模量：346221081.2703.1361921056.15mmhI腹板底边缘处的截面模量：346231044.1103.1361056.15mmyI弯矩：mkNM12120100由弯矩得最大应力为：24633/90.1041044.111012mmNWMw腹板的剪应力为：23/50.464.2150/10100/mmNAFw翼缘和腹板连接处的折算应力；2222223/160/75.9750.4622.190.104mmNfmmNwff满足要求。4.解：Q235钢、查附表1-2得2/185mmNfwt，2/125mmNfwv，2/215mmNfwc焊缝有效截面形心位置：mmyy13.134)1218812126/(]2/18812188)6188(12126[2焊缝对x轴的惯性矩为：1261881212y2y1463221070.1512/18812)2/18813.134(12188)613.13412188(12126mmIx翼缘焊缝边缘的截面模量：346111083.2313.134121881070.15mmyIWx翼缘和腹板连接处的截面模量：346221014.2913.1341881070.15188mmyIWx腹板底边缘处的截面模量：346231070.1113.1341070.15mmyIWx弯矩：FM120由翼缘上边缘处焊缝拉应力241/1851083.23120mmNfFWMwtt得：kNF38.367120/1083.231854由腹板下边缘处焊缝压应力243/2151070.11120mmNfFWMwcc得：kNF62.209120/1070.112154由腹板焊缝单独承担剪力，腹板的剪应力x1x25005.65.61975.6xxyy2/125)12188/(/mmNfFAFwvw得：kNF00.28212188125腹板下端点正应力、剪应力均较大，由腹板下端点的折算应力222422/5.2031851.11.11218831070.111203mmNfFFwtc得：kNF84.158综上得该连接所能承受的最大荷载为kNF84.158。5.解：Q345B钢、2/200mmNfwf，mmhf8角焊缝有效截面的形心位置：mmxx41.43)6.55006.51972(/)2/1976.51972(1截面的惯性矩：46321023.19612/5006.52506.51972mmIwx462321011.1941.435006.512/1976.52)41.432/197(6.51972mmIwy4331034.21510)11.1923.196(mmIIJwywx扭矩：FFT59.461)41.43205300(由扭矩产生的最大应力266/2001088.5351034.21525059.461mmNfFFJrTwfyTf得：kNF22.3731088.535/2006266/24420022.11023.3291034.215)41.43197(59.461mmNfFFJrTwffxTf得：kNF12.7411023.329/2446由力F产生的应力26/2441074.1996.55006.51972mmNfFFAFwffwVf得：kNF59.12211074.199/2446由最大应力点的折算应力262626622/2001032.689)1088.535(22.11074.1991023.329)(mmNfFFFFwfTffVfTf得：kNF14.2901032.689/2006综上得该连接所能承受的最大荷载为kNF14.290。6.解：Q235B钢、2/140mmNfbv，2/305mmNfbc单个螺栓的抗剪承载力设计值：kNfdnNbvvbv44.1061404222422kNftdNbcbc94.933051422kNNNNbcbvb94.93),min(min一侧所需的螺栓数目为：45.794.93/700/minbNNn（个），取8n螺栓的布置如图所示：净截面强度验算：螺栓群最外端净截面强度：223/215/97.187]14)5.234360/[(10700/mmNfmmNANn净截面强度满足要求。7.解：Q235钢、2/140mmNfbv，2/305mmNfbc，2/170mmNfbt506080808045804510NN806050单个螺栓的抗剪承载力设计值：kNfdnNbvvbv22.531404221422kNftdNbcbc78.1203051822kNNNNbcbvb22.53),min(min单个螺栓的抗拉承载力设计值：kNfAfdNbtebtebt51.5117030342（1）牛腿下支托承受剪力时由受力最大的螺栓承受的拉力kNNFFymMyNbti51.51133.0)32024016080(23201602222211得：kNF32.386故支托承受剪力时该连接所能承受得最大荷载设计值为kNF32.386。（2）牛腿下支托不承受剪力时由受力最大的螺栓