【電大】鋼結(jié)構(gòu)（本）匯總整編一、單項(xiàng)選擇題1下列關(guān)于我國(guó)目前的鋼結(jié)構(gòu)設(shè)計(jì)說(shuō)法正確的一項(xiàng)是（ C ）C.除疲勞計(jì)算按容許應(yīng)力幅、應(yīng)力按彈性狀態(tài)計(jì)算外，其他采用以概率理論為基礎(chǔ)的近似概率極限狀態(tài)設(shè)計(jì)方法2按承載力極限狀態(tài)設(shè)計(jì)鋼結(jié)構(gòu)時(shí)，應(yīng)考慮（ C ）C荷載效應(yīng)的基本組合，必要時(shí)尚應(yīng)考慮荷載效應(yīng)的偶然組合3在結(jié)構(gòu)設(shè)計(jì)中，失效概率與可靠指標(biāo)的關(guān)系為（ B ）B 越大，越小，結(jié)構(gòu)可靠性越差4下列鋼結(jié)構(gòu)計(jì)算所取荷載設(shè)計(jì)值和標(biāo)準(zhǔn)值，符合鋼結(jié)構(gòu)設(shè)計(jì)規(guī)范的一組是 （ B ）B計(jì)算結(jié)構(gòu)或構(gòu)件的強(qiáng)度、穩(wěn)定性以及連接的強(qiáng)度時(shí)，應(yīng)采用荷載設(shè)計(jì)值；5塔架和桅桿的結(jié)構(gòu)形式屬于（ A ） A高聳鋼結(jié)構(gòu) 6相同跨度的結(jié)構(gòu)承受相同的荷載，普通鋼屋架的重量為鋼筋混凝土屋架的（B1/41/3）7在構(gòu)件發(fā)生斷裂破壞前，具有明顯先兆的情況是（ B ） B 塑性破壞 8鋼材的設(shè)計(jì)強(qiáng)度是根據(jù)（ C ）確定的 C屈服點(diǎn) 9鋼材的三項(xiàng)主要力學(xué)性能為（ A ） A抗拉強(qiáng)度、屈服點(diǎn)、伸長(zhǎng)率 10鋼材的伸長(zhǎng)率是反映材料（ D ）的性能指標(biāo)。 D 塑性變形能力11鋼結(jié)構(gòu)對(duì)動(dòng)力荷載適應(yīng)性較強(qiáng)，是由于鋼材具有（C ） C良好的韌性 12四種厚度不等的16Mn鋼鋼板，其中（ A ）鋼板設(shè)計(jì)強(qiáng)度最高 A16mm 13鋼中硫和氧的含量超過(guò)限量時(shí)，會(huì)使鋼材（ B ） B熱脆 14以下關(guān)于應(yīng)力集中的說(shuō)法中正確的是（ B ） B應(yīng)力集中產(chǎn)生同號(hào)應(yīng)力場(chǎng)，使塑性變形受到限制15鋼材在低溫下，沖擊韌性（ B ） B降低16鋼材經(jīng)歷了應(yīng)變硬化（應(yīng)變強(qiáng)化）之后（ A ） A強(qiáng)度提高 17下列因素與鋼構(gòu)件發(fā)生脆性破壞無(wú)直接關(guān)系的是（ A ） A鋼材屈服點(diǎn)的大小 18鋼材的疲勞破壞屬于（ C ） C脆性破壞 19對(duì)鋼材的疲勞強(qiáng)度影響不顯著的是（ C ） C鋼種 20沸騰鋼與鎮(zhèn)靜鋼冶煉澆注方法的主要不同之處是（ C ） C沸騰鋼不加脫氧劑 1、焊接殘余應(yīng)力不影響構(gòu)件的（ B ） B靜力強(qiáng)度 2、在彈性階段，側(cè)面角焊縫應(yīng)力沿長(zhǎng)度方向的分布為（ C ）C兩端大、中間小 3、焊縫長(zhǎng)度方向與作用力垂直的角焊縫是（ A ）A正面角焊縫 4、關(guān)于重級(jí)工作制吊車焊接吊車梁的腹板與上翼緣間的焊縫說(shuō)法正確的是（ D ）D可采用二級(jí)焊透對(duì)接焊縫5、在鋼梁底面設(shè)有吊桿，其拉力設(shè)計(jì)值為650kN（靜載），吊桿通過(guò)節(jié)點(diǎn)板將荷載傳給鋼梁，節(jié)點(diǎn)板采用雙面焊縫焊于梁下翼緣，=10mm，=160MPa，則每面焊縫長(zhǎng)度為（260mm）6、部分焊透的對(duì)接焊縫的計(jì)算應(yīng)按（ B ）。B角焊縫 7、斜角焊縫主要用于（ C ）。C 鋼管結(jié)構(gòu) 8、按照施焊位置分為平焊、橫焊、立焊及仰焊，其中操作條件最差的是（ D ）仰焊9、一個(gè)承受剪力作用的普通螺栓在抗剪連接中的承載力是（ D ）D A、B中的較小值10、C級(jí)普通螺栓連接可用于（ B ）B屋蓋支撐的連接 11、下列關(guān)于螺栓在構(gòu)件排列的相關(guān)要求說(shuō)法有誤的一項(xiàng)是（ A ）A垂直于受力方向的受拉構(gòu)件，各排螺栓的中距越小越好 12、承受軸心力作用的高強(qiáng)度螺栓摩擦型受剪切連接中，其凈截面強(qiáng)度驗(yàn)算公式，下列與軸心拉桿所受的力相比關(guān)系正確的是（ B ）。B 13、高強(qiáng)度螺栓摩擦型連接和承壓型連接主要區(qū)別是（D）。D. 設(shè)計(jì)計(jì)算方法不同14、摩擦型連接的高強(qiáng)度螺栓在桿軸方向受拉時(shí)，其承載力說(shuō)法正確的一項(xiàng)是（ C ）C與螺栓直徑有關(guān) 15、高強(qiáng)度螺栓摩擦型連接受剪破壞時(shí)，承載能力極限狀態(tài)的確定因素是（ B ）。B連接板件間的摩擦力 16、13在鋼梁底面設(shè)置吊桿，其拉力設(shè)計(jì)值為650kN，吊桿通過(guò)T形連接件將荷載傳給鋼梁，T形連接件與鋼梁下翼緣板采用雙排88級(jí)M20高強(qiáng)度螺栓摩擦型連接，預(yù)拉力P=125kN，抗劃系數(shù)U=045，則高強(qiáng)度螺栓的數(shù)量應(yīng)為（ C ）。C8 17、采用高強(qiáng)度螺栓摩擦型連接與承壓型連接，在相同螺栓直徑的條件下，它們對(duì)螺栓孔的要求是（ A ）A摩擦型連接孔要求略大，承壓型連接孔要求略小18、承壓型高強(qiáng)度螺栓可用于（D）。D 承受靜力荷載或間接承受動(dòng)力荷載結(jié)構(gòu)的連接19、每個(gè)受剪力作用的摩擦型高強(qiáng)度螺栓所受的拉力應(yīng)低于其預(yù)拉力的（C）。C 08倍 20、圖1所示為高強(qiáng)度螺栓連接，在彎矩M的作用下，可以認(rèn)為中和軸在（C螺栓 3上） 1、實(shí)腹式軸心受拉構(gòu)件計(jì)算的內(nèi)容包括（D）。D強(qiáng)度、剛度（長(zhǎng)細(xì)比）2、對(duì)有孔眼等削弱的軸心拉桿承載力，鋼結(jié)構(gòu)設(shè)計(jì)規(guī)范采用的準(zhǔn)則為凈截面（ B ）B平均應(yīng)力達(dá)到鋼材屈服點(diǎn) 3、一寬度為、厚度為的鋼板上有一直徑為的孔，則鋼板的凈截面面積為（ C ）C 4、下列關(guān)于軸心壓桿的強(qiáng)度與穩(wěn)定的計(jì)算公式（為構(gòu)件的凈截面，為構(gòu)件的毛截面）正確的一項(xiàng)是（ B ） 軸心壓桿的強(qiáng)度與穩(wěn)定，應(yīng)分別滿足（ B ）。B 5、計(jì)算格構(gòu)式軸心受壓柱整體穩(wěn)定時(shí)，用換算長(zhǎng)細(xì)比代替，這是考慮（ D ）D綴材剪切變形的影響6、雙肢綴條式軸心受壓柱繞實(shí)軸和繞虛軸等穩(wěn)定的要求是（B ）B 7、確定軸心受壓實(shí)腹柱的截面形式時(shí)，應(yīng)使兩個(gè)主軸方向的長(zhǎng)細(xì)比盡可能接近，其目的是（ C ） C達(dá)到經(jīng)濟(jì)效果 8、提高軸心受壓構(gòu)件局部穩(wěn)定常用的合理方法是（D ） D設(shè)置橫向加勁肋9、為提高軸心受壓構(gòu)件的整體穩(wěn)定，在構(gòu)件截面面積不變的情況下，構(gòu)件截面的形式應(yīng)使其面積分布（ B ）。 B 盡可能遠(yuǎn)離形心 10、軸心受壓構(gòu)件發(fā)生彈性失穩(wěn)時(shí)，截面上的平均應(yīng)力（ C ）。 C 低于鋼材比例極限11、軸心受壓構(gòu)件柱腳底板的面積主要取決于（ C ）C基礎(chǔ)材料的抗壓能力12、兩端鉸接的理想軸心受壓構(gòu)件，當(dāng)截面形式為雙軸對(duì)稱十字形時(shí)，在軸心壓力作用下構(gòu)件可能發(fā)生（C）。C扭轉(zhuǎn)屈曲 13、在下列關(guān)于柱腳底板厚度的說(shuō)法中，錯(cuò)誤的是（ C ）C 其它條件相同時(shí)，四邊支承板應(yīng)比三邊支承板更厚些14、下列軸心受拉構(gòu)件，可不驗(yàn)算正常使用極限狀態(tài)的是 （D）D 預(yù)應(yīng)力拉桿15、雙肢格構(gòu)式受壓柱，實(shí)軸為xx，虛軸為yy，應(yīng)根據(jù)（ B ）確定肢件間距離。B 16、承受橫向荷載的構(gòu)件稱為（ A ）A 受彎構(gòu)件 17、鋼梁彎曲應(yīng)力的發(fā)展三個(gè)階段分別是（ A ）A彈性工作階段、彈塑性工作階段、塑性工作階段18、提高腹板的穩(wěn)定性，相對(duì)比較經(jīng)濟(jì)的措施是（ A ）A增大腹板面積19、梁的撓度驗(yàn)算其實(shí)是（ C ）C驗(yàn)算梁的剛度20、計(jì)算工字形截面梁的抗彎強(qiáng)度采用公式，取=105，梁的受壓翼緣外伸肢寬厚比不大于（ B ）A B 1、驗(yàn)算工字形截面梁的折算應(yīng)力的公式，式中、應(yīng)為（ D ）D驗(yàn)算截面中驗(yàn)算點(diǎn)的正應(yīng)力和剪應(yīng)力2、不考慮腹板屈曲后強(qiáng)度，工字形截面梁腹板高厚比=100時(shí)，梁腹板可能（ D ）D因剪應(yīng)力引起屈曲，需設(shè)橫向加勁肋3、梁上作用較大固定集中荷載時(shí)，其作用點(diǎn)處應(yīng)（ B ）。B 設(shè)置支承加勁肋4、焊接工字形截面梁腹板設(shè)置加勁肋的目的是（ D ）。D 提高梁的局部穩(wěn)定性5、保證工字形截面梁受壓翼緣局部穩(wěn)定的方法是（ D ）D限制其寬厚比6、對(duì)于承受均布荷載的熱軋H型鋼簡(jiǎn)支梁，應(yīng)計(jì)算（ D ）D抗彎強(qiáng)度、抗剪強(qiáng)度、整體穩(wěn)定、撓度7、一簡(jiǎn)支箱形截面梁，跨度60m，梁寬1m，梁高36m，鋼材為16Mn，在垂直荷栽作用下，梁的整體穩(wěn)定系數(shù)為（ D ）D1008、在焊接組合梁的設(shè)計(jì)中，腹板厚度應(yīng)（ C ）。C 厚薄相當(dāng)D 厚薄無(wú)所謂9、在焊接工字形組合梁中，翼緣與腹板連接的角焊縫計(jì)算長(zhǎng)度不受的限制，是因?yàn)椋?D ）。D 內(nèi)力沿側(cè)面角焊縫全長(zhǎng)分布的關(guān)系10、工字形截面梁受壓翼緣，對(duì)Q235鋼，保證局部穩(wěn)定的寬厚比限值為，對(duì)Q345鋼，此寬厚比限值應(yīng)為（ A ）A比15更小 11、為了提高梁的整體穩(wěn)定，最經(jīng)濟(jì)有效的辦法是（B）B 增加側(cè)向支撐點(diǎn) 12、當(dāng)無(wú)集中荷載作用時(shí)，焊接工字形截面梁翼緣與腹板的焊縫主要承受（ C ）。C 水平剪力13、圖1所示為加強(qiáng)受壓翼緣的工字形等截面簡(jiǎn)支組合梁，抗側(cè)移支撐桿設(shè)置對(duì)提高梁的整體穩(wěn)定性效果最好。（A）圖114、單軸對(duì)稱的實(shí)腹式壓彎構(gòu)件整體穩(wěn)定性計(jì)算公式和中的、說(shuō)法正確的是（ D ）D和為單軸對(duì)稱截面繞非對(duì)稱軸較大和較小翼緣最外纖維的毛截面模量，值相同15、有側(cè)移的單層鋼框架，采用等截面柱，柱與基礎(chǔ)固接，與橫梁鉸接，框架平面內(nèi)柱的計(jì)算長(zhǎng)度系數(shù)為（ A ）A203 16、單軸對(duì)稱截面的壓彎構(gòu)件，當(dāng)彎矩作用在對(duì)稱軸平面內(nèi)，且使較大翼緣受壓時(shí)，構(gòu)件達(dá)到臨界狀態(tài)的應(yīng)力分布說(shuō)法正確的是（ A ）A 可能在拉、壓側(cè)都出現(xiàn)塑性 17、實(shí)腹式偏心受壓構(gòu)件在彎矩作用平面內(nèi)整體穩(wěn)定驗(yàn)算公式中的主要是考慮 （ A ）。A 截面塑性發(fā)展對(duì)承載力的影響 18、單軸對(duì)稱截面的壓彎構(gòu)件，一般宜使彎矩（ A ）A繞非對(duì)稱軸作用 19、計(jì)算格構(gòu)式壓彎構(gòu)件的綴材時(shí)，剪力應(yīng)?。?C ）。C 構(gòu)件實(shí)際剪力設(shè)計(jì)值或由公式計(jì)算的剪力兩者中較大值20、關(guān)于屋架的形式說(shuō)法有誤的一項(xiàng)是（ B ）B 屋架外形選擇最重要的方面是用料經(jīng)濟(jì)，其次是建筑物用途 二、判斷題1鋼結(jié)構(gòu)在涂刷油漆前應(yīng)徹底除銹，油漆質(zhì)量和涂層厚度均應(yīng)符合相關(guān)規(guī)范要求。（）2正常使用極限狀態(tài)包括構(gòu)件和連接的強(qiáng)度破壞、疲勞破壞和因過(guò)度變形而不適于繼續(xù)承載，結(jié)構(gòu)和構(gòu)件喪失穩(wěn)定，結(jié)構(gòu)轉(zhuǎn)變?yōu)闄C(jī)動(dòng)體系和結(jié)構(gòu)傾覆。（）3輕鋼結(jié)構(gòu)主要包括鋼-混凝土組合梁和鋼管混凝土柱等。（）4鋼結(jié)構(gòu)計(jì)算的目的在于保證所設(shè)計(jì)的結(jié)構(gòu)和構(gòu)件滿足預(yù)期的各種功能。（）5用作鋼結(jié)構(gòu)的鋼材必須具有較高的強(qiáng)度、足夠的變形能力和良好的工藝性能。（）6鋼材在單向受壓（粗而短的試件）時(shí)，受力性能基本和單向受拉時(shí)相同。（）7鋼筋的冷彎試驗(yàn)是按照有關(guān)規(guī)定的彎心直徑在試驗(yàn)機(jī)上采用沖頭加壓，使試件完成45，如試件外表面不出現(xiàn)裂紋和分層，即為合格。（）8碳含量在0.120.20范圍內(nèi)碳素鋼，可焊性好。（）9實(shí)踐證明，構(gòu)件的壓力水平越低，越容易發(fā)生疲勞破壞。（）10槽鋼分為普通槽鋼和輕型槽鋼，其編號(hào)的依據(jù)是其截面寬度（單位m）。（）1、鋼結(jié)構(gòu)的連接就是把板材或型鋼組合成構(gòu)件，再將構(gòu)件組合成結(jié)構(gòu)，以保證結(jié)構(gòu)的共同受力。( )2、側(cè)面角焊縫主要承受剪力、塑性較差、但彈性模量較高，強(qiáng)度也高。（ ）3、采用角焊縫連接的板件必須坡口，焊縫金屬不可直接充填在由被連接板件形成的直角或斜角區(qū)域內(nèi)。（ ）4、焊縫的連接形式按被連接板件的相互位置可分為對(duì)接、搭接、T型連接和角部連接四種形式。( )5、在荷載作用下，如果焊縫長(zhǎng)度適宜，當(dāng)焊縫兩端點(diǎn)處的應(yīng)力達(dá)到屈服強(qiáng)度后，繼續(xù)加載，應(yīng)力會(huì)逐漸均勻。( )6、焊接冷卻后產(chǎn)生的變形稱為焊接殘余變形，這時(shí)焊件中的應(yīng)力稱為焊接殘余應(yīng)力。( )7、9螺栓錯(cuò)列排列比較簡(jiǎn)單整齊，布置緊湊，所用連接板尺寸小，但對(duì)構(gòu)件截面的削弱較大。（ ）8、普通螺栓連接的抗剪承載力，應(yīng)考慮螺栓桿受剪和孔壁承壓兩種情況。( )9、高強(qiáng)度螺栓連接時(shí)的摩擦力隨外力增大而增大，接近破壞時(shí)，與桿身共同承擔(dān)剪力。（ ）10、高強(qiáng)度螺栓群在扭矩或扭矩、剪力共同作用時(shí)的剪力計(jì)算方法與普通螺栓群完全不同，其應(yīng)采用高強(qiáng)度螺栓承載力的極限值進(jìn)行計(jì)算。( ) 1、軸心受力構(gòu)件包括軸心受拉構(gòu)件和軸心受壓構(gòu)件。( ) 2、軸心受力構(gòu)件的強(qiáng)度制其長(zhǎng)細(xì)比來(lái)保證。( ) 3、單軸對(duì)稱截面構(gòu)件繞對(duì)稱軸屈曲時(shí)，在發(fā)生彎曲變形的同時(shí)絕對(duì)不發(fā)生扭轉(zhuǎn)。（）4、殘余應(yīng)力對(duì)軸心受壓構(gòu)件承載力的影響，主要考慮縱向殘余應(yīng)力。( )5、具有初始彎曲的壓桿，壓力一開(kāi)始作用，桿件就產(chǎn)生撓曲，并隨著荷載的增大而增加。( )6、組成軸心受壓構(gòu)件的板件過(guò)薄，在壓力作用下容易發(fā)生局部失穩(wěn)。( )7、實(shí)腹式軸心受壓構(gòu)件一般采用單軸對(duì)稱截面來(lái)避免彎曲失穩(wěn)。( )8、格構(gòu)式構(gòu)件軸心受壓構(gòu)件撓實(shí)軸的穩(wěn)定性計(jì)算與實(shí)腹式軸心受壓構(gòu)件相同。( )9、軸心受壓柱的柱頭構(gòu)造應(yīng)使柱身的內(nèi)力可靠地傳給基礎(chǔ)，并和基礎(chǔ)牢固地連接。( )10、組合梁相比型鋼梁加工簡(jiǎn)單，成本較低，因而應(yīng)優(yōu)先選用組合梁。( )1、梁主要用于承受彎矩，為了充分發(fā)揮材料的強(qiáng)度，其截面通常設(shè)計(jì)成高而窄的形式。（）2、橫向荷載的臨界值僅與它自身大小有關(guān)，而與沿梁高的作用位置無(wú)關(guān)。（）3、對(duì)于承受靜力荷載和間接承受動(dòng)力荷載的組合梁，堅(jiān)決不允許腹板在梁整體失調(diào)之前屈曲。（）4、型鋼梁腹板和翼緣的寬厚比都比較小，局部穩(wěn)定常可得以保證，不需要進(jìn)行驗(yàn)算（）5、鋼結(jié)構(gòu)中主梁和次梁的連接形式一般有疊接和平接兩種。（）6、同時(shí)承受軸向拉力或彎矩的構(gòu)件稱為拉彎構(gòu)件，同時(shí)承受軸向壓力或彎矩的構(gòu)件稱為壓彎構(gòu)件。（）7、壓彎構(gòu)件的受壓翼緣板，其應(yīng)力情況與梁受拉翼緣基本相同，因此其受壓翼緣寬厚比限梁受拉翼緣的寬厚比限制相同。（）8、梁與柱的剛性連接要求連接節(jié)點(diǎn)不僅能可靠地傳遞剪力而且能有效地傳遞彎矩。（）9、鋼材的切割有剪切、鋸切和氣割等方法，其中剪切機(jī)切割最復(fù)雜。（）10、焊接鋼結(jié)構(gòu)最費(fèi)工的工序是制孔、裝配和打鉚。（）三、簡(jiǎn)答題1、鋼結(jié)構(gòu)和其他材料的結(jié)構(gòu)相比具有哪些特點(diǎn)？答：（1）建筑鋼材強(qiáng)度高，塑性和韌性好；（2）鋼結(jié)構(gòu)的重量輕；（3）材質(zhì)均勻，與力學(xué)計(jì)算的假定比較符合；（4）鋼結(jié)構(gòu)制作簡(jiǎn)便，施工工期短；（5）鋼結(jié)構(gòu)密閉性好；（6）鋼結(jié)構(gòu)耐腐蝕性差；（7）鋼材耐熱不耐火；（8）鋼結(jié)構(gòu)可能發(fā)生脆性斷裂。2.鋼材“耐熱不耐火”的含義是什么？規(guī)范對(duì)其有何規(guī)定？答：鋼材受熱，當(dāng)溫度在200以內(nèi)時(shí)，其主要力學(xué)性能，如屈服點(diǎn)和彈性模量降低不多。溫度超過(guò)200后，材質(zhì)發(fā)生較大變化，不僅強(qiáng)度逐步降低，還會(huì)發(fā)生藍(lán)脆和徐變現(xiàn)象。溫度達(dá)600時(shí)，鋼材進(jìn)入塑性狀態(tài)不能繼續(xù)承載。因此，鋼結(jié)構(gòu)設(shè)計(jì)規(guī)范規(guī)定鋼材表面溫度超過(guò)150后即需加以隔熱防護(hù)，對(duì)需防火的結(jié)構(gòu)，應(yīng)按相關(guān)的規(guī)范采取防火保護(hù)措施。3、鋼結(jié)構(gòu)設(shè)計(jì)必須滿足的功能包括哪些方面？答：（1）應(yīng)能承受在正常施工和正常使用時(shí)可能出現(xiàn)的各種情況，包括荷載和溫度變化、基礎(chǔ)不均勻沉降以及地震作用等；（2）在正常使用情況下結(jié)構(gòu)具有良好的工作性能；（3）在正常維護(hù)下結(jié)構(gòu)具有足夠的耐久性；（4）在偶然事件發(fā)生時(shí)及發(fā)生后仍能保持必需的整體穩(wěn)定性。4、時(shí)效硬化和人工時(shí)效各指什么？答：時(shí)效硬化：在高溫時(shí)熔化于鐵中的少量碳和氮，隨著時(shí)間的增長(zhǎng)逐漸從純鐵中析出，形成自由碳化合物和氮化物，對(duì)純鐵體的塑性變形起遏制作用，從而使鋼材的強(qiáng)度提高，塑性、韌性下降，這種現(xiàn)象稱為時(shí)效硬化，俗稱老化。人工時(shí)效：時(shí)效硬化的過(guò)程一般很長(zhǎng)，在材料塑性變形后加熱，可以使時(shí)效硬化發(fā)展特別迅速，這種方法稱為人工時(shí)效。5、什么情況下會(huì)產(chǎn)生應(yīng)力集中，應(yīng)力集中對(duì)鋼材性能有何影響？答：在鋼結(jié)構(gòu)的構(gòu)件中可能存在孔洞、槽口、凹角、截面突然改變以及鋼材內(nèi)部缺陷等，使構(gòu)件中的應(yīng)力分布將不再保持均勻，而是在某些區(qū)域產(chǎn)生局部高峰應(yīng)力，在另外一些區(qū)域則應(yīng)力降低，形成所謂應(yīng)力集中現(xiàn)象。應(yīng)力集中會(huì)使鋼材變脆的趨勢(shì)。6、簡(jiǎn)述鋼材的疲勞破壞過(guò)程答：鋼材在反復(fù)荷載作用下，結(jié)構(gòu)的抗力及性能都會(huì)發(fā)生重要變化，甚至發(fā)生疲勞破壞。根據(jù)試驗(yàn)，在直接的連續(xù)反復(fù)的動(dòng)力荷載作用下，鋼材的強(qiáng)度將降低，即低于一次靜力荷載作用下的拉伸試驗(yàn)的極限強(qiáng)度，這種現(xiàn)象稱為鋼材的疲勞。疲勞破壞表現(xiàn)為突發(fā)的脆性斷裂。7、鋼材常見(jiàn)的冶金缺陷有哪些，各自的具體含義是什么？答：鋼材常見(jiàn)的冶金缺陷包括偏析、非金屬夾雜、氣孔、裂紋及分層等。偏析：是指鋼材中化學(xué)成分不一到和不均勻，特別是硫、磷偏析嚴(yán)重造成鋼材的性能惡化；非金屬夾雜：是指鋼中含有硫化物與氧化物等雜質(zhì)；氣孔：是澆鑄鋼錠時(shí)，由氧化鐵與碳作用所生成的一氧化碳?xì)怏w不能充分逸出而形成的。8簡(jiǎn)述溫度對(duì)鋼材性能產(chǎn)生的影響。 答：鋼材性能隨溫度改變而有所變化，總的趨勢(shì)是溫度升高，鋼材強(qiáng)度降低，應(yīng)變?cè)龃?；反之溫度降低，鋼材?qiáng)度會(huì)略有增加，同時(shí)鋼材會(huì)因塑性和韌性降低而變脆。1、鋼結(jié)構(gòu)焊接連接方法的優(yōu)點(diǎn)和缺點(diǎn)有哪些？答：優(yōu)點(diǎn)（1）焊件間可以直接相連，構(gòu)造簡(jiǎn)單，制作加工方便；（2）不削弱截面，節(jié)省材料；（3）連接的密閉性好，結(jié)構(gòu)的剛度大；（4）可實(shí)現(xiàn)自動(dòng)化操作，提高焊接結(jié)構(gòu)的質(zhì)量。缺點(diǎn)（1）焊縫附近的熱影響區(qū)內(nèi)，鋼材的金相組織發(fā)生改變，導(dǎo)致局部材質(zhì)變脆；（2）焊接殘余應(yīng)力和殘余變形使受壓構(gòu)件承載力降低；（3）焊接結(jié)構(gòu)對(duì)裂紋很敏感，局部裂紋一旦發(fā)生，容易擴(kuò)展至整個(gè)截面，低溫冷脆問(wèn)題也較為突出。2、高強(qiáng)度螺栓的預(yù)拉力設(shè)計(jì)值P的計(jì)算公式中，系數(shù)的確定考慮了哪些因素？答：（1）擰緊螺栓時(shí)螺栓同時(shí)受到由預(yù)拉力引起的拉應(yīng)力和由扭矩引起的扭轉(zhuǎn)剪應(yīng)力作用；（2）施工時(shí)為了彌補(bǔ)高強(qiáng)度螺栓預(yù)拉應(yīng)力的松弛損失，一般超張拉5%10%，為此考慮一個(gè)超張拉系數(shù)0.9；（3）考慮螺栓材質(zhì)的不均勻性，引入一個(gè)折減系數(shù)0.9；（4）由于以螺栓的抗拉引吭高歌為準(zhǔn)，為了安全引入一個(gè)安全系數(shù)0.9。3、抗剪普通螺栓有哪幾種可能的破壞形式？如何防止？答：破壞形式：（1）當(dāng)螺栓桿直徑較小而板件較厚時(shí)，螺栓桿可能被剪斷；（2）當(dāng)螺栓桿直徑較大、板件較薄時(shí)，板件可能被擠壞，由于螺栓桿和板件的擠壓是相對(duì)的，故也把這種破壞叫做螺栓承壓破壞；（3）板件截面可能因螺栓孔削弱太多而被拉斷；（4）端距太小，端距范圍內(nèi)的板件可能被螺栓桿沖剪破壞。防止：第（3）種破壞形式屬于構(gòu)件的強(qiáng)度計(jì)算，第（4）種破壞形式通過(guò)限制螺栓端距大于或等于2d0加以避免。因此，抗剪螺栓連接計(jì)算只考慮第（1）、（2）種破壞形式。4、減少焊接應(yīng)力和焊接變形的設(shè)計(jì)措施有哪些？答：（1）盡可能使焊縫對(duì)稱于構(gòu)件截面的中性軸，以減少焊接變形；（2）采用適宜的焊腳尺寸和焊縫長(zhǎng)度；（3）焊縫不宜過(guò)分集中（4）盡量避免兩條或三條焊縫垂直交叉（5）盡量避免在母材厚度方向的收縮應(yīng)力。1、實(shí)腹式軸心受壓構(gòu)件進(jìn)行截面選擇時(shí)，應(yīng)主要考慮的原則是什么？答；（1）面積的分布應(yīng)盡量開(kāi)展，以增加截面的慣性矩和回轉(zhuǎn)半徑，提高柱的整體穩(wěn)定承載力和剛度；（2）兩個(gè)主軸方向盡量等穩(wěn)定，以達(dá)到經(jīng)濟(jì)的效果；（3）便于與其他構(gòu)件進(jìn)行連接，盡量能構(gòu)造簡(jiǎn)單，制造省工，取材方便。2、計(jì)算格構(gòu)式軸心受壓構(gòu)件繞軸的整體穩(wěn)定時(shí)，為什么采用換算長(zhǎng)細(xì)比？答：對(duì)于格構(gòu)式軸心受壓構(gòu)件，當(dāng)繞虛軸失穩(wěn)時(shí)，因肢件之間并不是連續(xù)的板而只是每隔一定距離用綴條或綴板聯(lián)系起來(lái)，構(gòu)件的剪切變形較大，剪力造成的附加影響不能忽略，通常采用換算長(zhǎng)細(xì)比來(lái)考慮綴材剪切變形對(duì)格構(gòu)式軸心受壓構(gòu)件繞虛軸的穩(wěn)定承載力的影響。3、簡(jiǎn)述實(shí)腹式軸心受壓構(gòu)件的設(shè)計(jì)步驟？答：（1）假定構(gòu)件的長(zhǎng)細(xì)比，求出需要的截面面積A。（2）計(jì)算兩個(gè)主軸所需要的回轉(zhuǎn)半徑(3)由計(jì)算的截面面積A和兩個(gè)主回轉(zhuǎn)半徑優(yōu)先選用型鋼。（4）由所需要的A、h、b等，以及同時(shí)考慮構(gòu)造要求、局部穩(wěn)定以及鋼材規(guī)格等，確定截面的初選尺寸。（5）構(gòu)件強(qiáng)度、穩(wěn)定和剛度驗(yàn)算4、鋼梁腹板計(jì)算高度如何取值？答：（1）軋制型鋼梁，為腹板在與上下翼緣相交接處兩內(nèi)弧起點(diǎn)間的距離；（2）焊接組合梁，為腹板高度；（3）鉚接組合梁，為上下翼緣與腹板連接的鉚釘（或高強(qiáng)螺栓）線間最近距離。1、什么是梁的整體失穩(wěn)現(xiàn)象？答：梁主要用于承受彎矩，為了充分發(fā)揮材料的強(qiáng)度，其截面通常設(shè)計(jì)成高而窄的形式。荷載作用在最大剛度平面內(nèi)。當(dāng)荷載較小時(shí)，僅在彎矩作用平面內(nèi)彎曲；當(dāng)荷載增大到某一數(shù)值后，梁在彎矩作用平面彎曲同時(shí)，將突然發(fā)生側(cè)向彎曲和扭轉(zhuǎn)，并喪失繼續(xù)承載的能力，這種現(xiàn)象稱為梁的彎扭屈曲或整體失穩(wěn)。2、根據(jù)彈性穩(wěn)定理論確定框架柱的計(jì)算長(zhǎng)度時(shí)，都做了哪些假定？答：（1）框架只承受作用于節(jié)點(diǎn)的豎向荷載，忽略橫梁荷載和水平荷載產(chǎn)生梁端彎矩的影響；（2）所有框架柱同時(shí)喪失穩(wěn)定，即所有框架柱同時(shí)達(dá)到臨界荷載；（3）失穩(wěn)時(shí)橫梁兩端的轉(zhuǎn)角相等。3、實(shí)腹式壓彎構(gòu)件截面選擇的具體步驟有哪些？答：（1）計(jì)算構(gòu)件的內(nèi)力設(shè)計(jì)值；即彎矩設(shè)計(jì)值MX、軸心壓力設(shè)計(jì)值N和剪力設(shè)計(jì)值V；（2）選擇截面形式；（3）確定鋼材及強(qiáng)度設(shè)計(jì)值；（4）確定彎矩作用平面內(nèi)和平面外的計(jì)算長(zhǎng)度；（5）根據(jù)經(jīng)驗(yàn)或已有資料初選截面尺寸；（6）對(duì)初選截面進(jìn)行強(qiáng)度驗(yàn)算、剛度驗(yàn)算、彎矩作用平面內(nèi)整體穩(wěn)定性驗(yàn)算、彎矩作用平面外整體穩(wěn)定驗(yàn)算和局部穩(wěn)定性驗(yàn)算，如驗(yàn)算不滿足要求，則對(duì)初選截面進(jìn)行調(diào)整，重新計(jì)算，直至滿足要求。4、為什么要在桁架組成的屋蓋結(jié)構(gòu)中設(shè)置支撐系統(tǒng)，支撐系統(tǒng)具體作用體現(xiàn)在哪些方面？答：屋架在其自身平面內(nèi)為幾何形狀不變體系并具有較大的剛度，能承受屋架平面內(nèi)的各種荷載。但是，平面屋架本身在垂直于屋架平面的側(cè)向（屋架平面外）剛度和穩(wěn)定性則很差，不能承受水平荷載。因此，為使屋架結(jié)構(gòu)有足夠的空間剛度和穩(wěn)定性，必須在屋架間設(shè)置支撐系統(tǒng)。保證結(jié)構(gòu)的空間整體作用；避免壓桿側(cè)向失穩(wěn)，防止拉桿產(chǎn)生過(guò)大的振動(dòng)承擔(dān)和傳遞水平荷載保證結(jié)構(gòu)安裝時(shí)的穩(wěn)定與方便。四、計(jì)算題1.如圖所示：已知焊縫承受的斜向靜力荷載設(shè)計(jì)值kN，偏心e為30mm，角焊縫的焊腳尺寸，實(shí)際長(zhǎng)度，鋼材為Q235B，焊條為E43型（=160N/mm2）， 焊縫強(qiáng)度增大系數(shù)取122。驗(yàn)算直角角焊縫的強(qiáng)度。圖1解：將F分解為垂直于焊縫和平行于焊縫的分力 直角角焊縫的強(qiáng)度滿足要求 2.如圖所示支柱上下端均為鉸接且設(shè)置支撐。支柱長(zhǎng)度為9m，在兩個(gè)三分點(diǎn)處均有側(cè)向支撐，以阻止柱在弱軸方向的過(guò)早失穩(wěn)。構(gòu)件的設(shè)計(jì)壓力為N250kN，容許長(zhǎng)細(xì)比。支柱截面為工字形I20a，。鋼材為Q235（）。驗(yàn)算此支柱的整體穩(wěn)定和剛度。（截面撓x(chóng)軸屬于a類截面，截面撓y軸屬于b類截面）a類截面的整體穩(wěn)定系數(shù)：01234567891100.5630.5550.5480.5410.5340.5270.5200.5140.5070.500b類截面的整體穩(wěn)定系數(shù)：01234567891400.3450.3410.3370.3330.3290.3260.3220.3180.3150.311圖1解：先計(jì)算長(zhǎng)細(xì)比， 計(jì)算得，取 根據(jù) 所以此柱的整體穩(wěn)定性和剛度均滿足要求。3.圖2所示簡(jiǎn)支梁長(zhǎng)6m，采用I36a（,），已知單位長(zhǎng)度得質(zhì)量為59.9kg/m，梁的自重為59.99.8587N/m，cm4，cm3，cm，mm。梁上作用恒荷載，荷載密度q=35000N/m，荷載分項(xiàng)系數(shù)1.2，截面塑性發(fā)展系數(shù)，。試驗(yàn)算此梁的正應(yīng)力及支座處剪應(yīng)力。（13分）q圖2【解】：梁自重產(chǎn)生的彎矩為： Nm （2分） 外荷載在跨中產(chǎn)生的最大彎矩為： Nm （2分） 總彎矩為： Nm （1分） 驗(yàn)算彎曲正應(yīng)力： N/mm2215 N/mm2 （3分） 驗(yàn)算支座處最大剪應(yīng)力： 支座處剪力： V1/2 (3500065876 )1.2 128113.2 N （2分） 剪應(yīng)力： 3N/mm2125 N/mm2 （3分）請(qǐng)您刪除一下內(nèi)容，O(_)O謝謝！2016年中央電大期末復(fù)習(xí)考試小抄大全，電大期末考試必備小抄，電大考試必過(guò)小抄Basketball can make a true claim to being the only major sport that is an American invention. From high school to the professional level, basketball attracts a large following for live games as well as television coverage of events like the National Collegiate Athletic Association (NCAA) annual tournament and the National Basketball Association (NBA) and Womens National Basketball Association (WNBA) playoffs. And it has also made American heroes out of its player and coach legends like Michael Jordan, Larry Bird, Earvin Magic Johnson, Sheryl Swoopes, and other great players. At the heart of the game is the playing space and the equipment. The space is a rectangular, indoor court. The principal pieces of equipment are the two elevated baskets, one at each end (in the long direction) of the court, and the basketball itself. The ball is spherical in shape and is inflated. Basket-balls range in size from 28.5-30 in (72-76 cm) in circumference, and in weight from 18-22 oz (510-624 g). For players below the high school level, a smaller ball is used, but the ball in mens games measures 29.5-30 in (75-76 cm) in circumference, and a womens ball is 28.5-29 in (72-74 cm) in circumference. The covering of the ball is leather, rubber, composition, or synthetic, although leather covers only are dictated by rules for college play, unless the teams agree otherwise. Orange is the regulation color. At all levels of play, the home team provides the ball. Inflation of the ball is based on the height of the balls bounce. Inside the covering or casing, a rubber bladder holds air. The ball must be inflated to a pressure sufficient to make it rebound to a height (measured to the top of the ball) of 49-54 in (1.2-1.4 m) when it is dropped on a solid wooden floor from a starting height of 6 ft (1.80 m) measured from the bottom of the ball. The factory must test the balls, and the air pressure that makes the ball legal in keeping with the bounce test is stamped on the ball. During the intensity of high school and college tourneys and the professional playoffs, this inflated sphere commands considerable attention. Basketball is one of few sports with a known date of birth. On December 1, 1891, in Springfield, Massachusetts, James Naismith hung two half-bushel peach baskets at the opposite ends of a gymnasium and out-lined 13 rules based on five principles to his students at the International Training School of the Young Mens Christian Association (YMCA), which later became Springfield College. Naismith (1861-1939) was a physical education teacher who was seeking a team sport with limited physical contact but a lot of running, jumping, shooting, and the hand-eye coordination required in handling a ball. The peach baskets he hung as goals gave the sport the name of basketball. His students were excited about the game, and Christmas vacation gave them the chance to tell their friends and people at their local YMCAs about the game. The association leaders wrote to Naismith asking for copies of the rules, and they were published in the Triangle, the school newspaper, on January 15,1892. Naismiths five basic principles center on the ball, which was described as large, light, and handled with the hands. Players could not move the ball by running alone, and none of the players was restricted against handling the ball. The playing area was also open to all players, but there was to be no physical contact between players; the ball was the objective. To score, the ball had to be shot through a horizontal, elevated goal. The team with the most points at the end of an allotted time period wins. Early in the history of basketball, the local YMCAs provided the gymnasiums, and membership in the organization grew rapidly. The size of the local gym dictated the number of players; smaller gyms used five players on a side, and the larger gyms allowed seven to nine. The team size became generally established as five in 1895, and, in 1897, this was made formal in the rules. The YMCA lost interest in supporting the game because 10-20 basketball players monopolized a gymnasium previously used by many more in a variety of activities. YMCA membership dropped, and basketball enthusiasts played in local halls. This led to the building of basketball gymnasiums at schools and colleges and also to the formation of professional leagues. Although basketball was born in the United States, five of Naismiths original players were Canadians, and the game spread to Canada immediately. It was played in France by 1893; England in 1894; Australia, China, and India between 1895 and 1900; and Japan in 1900. From 1891 through 1893, a soccer ball was used to play basketball. The first basketball was manufactured in 1894. It was 32 in (81 cm) in circumference, or about 4 in (10 cm) larger than a soccer ball. The dedicated basketball was made of laced leather and weighed less than 20 oz (567 g). The first molded ball that eliminated the need for laces was introduced in 1948; its construction and size of 30 in (76 cm) were ruled official in 1949. The rule-setters came from several groups early in the 1900s. Colleges and universities established their rules committees in 1905, the YMCA and the Amateur Athletic Union (AAU) created a set of rules jointly, state militia groups abided by a shared set of rules, and there were two professional sets of rules. A Joint Rules Committee for colleges, the AAU, and the YMCA was created in 1915, and, under the name the National Basketball Committee (NBC) made rules for amateur play until 1979. In that year, the National Federation of State High School Associations began governing the sport at the high school level, and the NCAA Rules Committee assumed rule-making responsibilities for junior colleges, colleges, and the Armed Forces, with a similar committee holding jurisdiction over womens basketball. Until World War II, basketball became increasingly popular in the United States especially at the high school and college levels. After World War II, its popularity grew around the world. In the 1980s, interest in the game truly exploded because of television exposure. Broadcast of the NCAA Championship Games began in 1963, and, by the 1980s, cable television was carrying regular season college games and even high school championships in some states. Players like Bill Russell, Wilt Chamberlain, and Lew Alcindor (Kareem Abdul-Jabbar) became nationally famous at the college level and carried their fans along in their professional basketball careers. The womens game changed radically in 1971 when separate rules for women were modified to more closely resemble the mens game. Television interest followed the women as well with broadcast of NCAA championship tourneys beginning in the early 1980s and the formation of the WNBA in 1997. Internationally, Italy has probably become the leading basketball nation outside of the United States, with national, corporate, and professional teams. The Olympics boosts basketball internationally and has also spurred the womens game by recognizing it as an Olympic event in 1976. Again, television coverage of the Olympics has been exceptionally important in drawing attention to international teams. The first professional mens basketball league in the United States was the National Basketball League (NBL), which debuted in 1898. Players were paid on a per-game basis, and this league and others were hurt by the poor quality of games and the ever-changing players on a team. After the Great Depression, a new NBL was organized in 1937, and the Basketball Association of America was organized in 1946. The two leagues came to agree that players had to be assigned to teams on a contract basis and that high standards had to govern the game; under these premises, the two joined to form the National Basketball Association (NBA) in 1949. A rival American Basketball Association (ABA) was inaugurated in 1967 and challenged the NBA for college talent and market share for almost ten years. In 1976, this league disbanded, but four of its teams remained as NBA teams. Unification came just in time for major television support. Several womens professional leagues were attempted and failed, including the Womens Professional Basketball League (WBL) and the Womens World Basketball Association, before the WNBA debuted in 1997 with the support of the NBA. James Naismith, originally from Al-monte, Ontario, invented basketball at the International YMCA Training School in Springfield, Massachusetts, in 1891. The game was first played with peach baskets (hence the name) and a soccer ball and was intended to provide indoor exercise for football players. As a result, it was originally a rough sport. Although ten of Naismiths original thirteen rules remain, the game soon changed considerably, and the founder had little to do with its evolution. The first intercollegiate game was played in Minnesota in 1895, with nine players to a side and a final score of nine to three. A year later, the first five-man teams played at the University of Chicago. Baskets were now constructed of twine nets but it was not until 1906 that the bottom of the nets were open. In 1897, the dribble was first used, field goals became two points, foul shots one point, and the first professional game was played. A year later, the first professional league was started, in the East, while in 1900, the first intercollegiate league began. In 1910, in