電大土木工程力學(xué)作業(yè)三答案參考

1、作業(yè)三參考答案一、選擇題1A 2 C 3D 4D 5A二、判斷題12 3 4 510 分）三、用位移法計算圖示連續(xù)梁，并繪出彎矩圖。各桿 EI 相同且為常數(shù)10kN/ m4m 6m解：（1）選取基本結(jié)構(gòu)如下圖所示， 1 為基本未知量?；窘Y(jié)構(gòu)（2）寫出位移法方程如下：k11 1+ F1P= 0 （3）計算系數(shù) k11 及自由項 F1P 令i=1E2I ，則 iAB =3i， iBC =2i 作 M 1 圖和 M P 圖如下：M1圖k11= 12i+2i =14i4040M P 圖（ kN m ）40F1P =kN m34）求解位移法基本未知量將系數(shù)及自由項代入位移法方程，得：F1P1 k11k

2、1140314i2021i5）作 M 圖19(20)1.9BA1.9M 圖( kN m )四、用位移法計算圖示剛架，并繪制彎矩圖。 （10 分）A2EIB 2EIEIC 2EIEIEF30kN/m15kND4m4m4m2m解： （1）選取基本結(jié)構(gòu)如下圖所示， 1、2 為基本未知量。2ABCEF1D基本結(jié)構(gòu)2）寫出位移法方程如下：k111+ k12 2+ F1P= 0k21 1+ k22 2+ F 2P= 03）計算系數(shù)及自由項令i= EI ，則 i = i =2i， i = i = i， i =4i令 4 AB = iBC =2i， iBE = iCF = i， iCD=4 i作 M 1圖、

3、M2 圖和 MP圖如下：D= 8i+4i+8i =20i=4iD= k12 =4ik11k21k21k22= 8i+4i=12i0 40B30CEFADM P 圖（ kN m ）F1P =40 kN mF2P =-30 kN m4）求解位移法基本未知量解得：將系數(shù)及自由項代入位移法方程，得：20i1+ 4i2+40= 0 4i1 +12i2-30= 0 1 75 1 28i9528i5）作 M 圖D五、用位移法計算圖示剛架，并繪出彎矩圖10 分）2EI EIB CDEIEIAEI解：1）選取基本結(jié)構(gòu)如圖所示， 1 為基本未知量。1A基本結(jié)構(gòu)（2）寫出位移法方程如下：k11 1+ F1P= 0

4、（3）計算系數(shù) k11 及自由項 F1P 令i = ELI ，則 iAD = iDE=i 作 M 1 圖和 MP 圖如下：M1圖Ek11= 4i+4i =8i12AMP圖qL2124）求解位移法基本未知量將系數(shù)及自由項代入位移法方程，得：qL2F1P12qL211 k118i96i5）作 M 圖由對稱性，得原結(jié)構(gòu)的48M2qL2M 圖如下：2qL2482qL2E2qL2482L5q48M圖六、用位移法計算圖示剛架 （利用對稱性 ），并繪出彎矩圖。各桿 EI 相同且為常 數(shù)。（10 分）ABCDEF18kN/m18kN/m6m6m6m6m解： （ 1）對稱結(jié)構(gòu)受對稱荷載作用，可簡化為如下結(jié)構(gòu)：1

5、8kN/m6m2）寫出位移法方程如下：k11 1+ F1P= 03）計算系數(shù) k11 及自由項 F1PEI令i= 6 ，則 iAB= iBE=i， iBG =2i6作 M 1 圖和 M P 圖如下：4iGGk11 = 4i+4i +2i =10iF1P= 54 kN m得：4）求解位移法基本未知量將系數(shù)及自由項代入位移法方程，F(xiàn)1P1k115410i5.4i5）作 M 圖由對稱性，得原結(jié)構(gòu)的 M 圖如下：64.832.464.8 (81)32.410.8B21.6 21.6M 圖( kN m )10.8 E10.8七、用力矩分配法計算圖示結(jié)構(gòu)，并繪出彎矩圖。各桿EI 相同且為常數(shù)。 （10分）

6、解：計算分配系數(shù)，3 EIBA =SBA +S BCEI 6 EI 0.4293+ 466BC 1 BA =10.429 0.571SCBCB = S +SSCB +S CD4 EI4 EI +63 EI 0.5714 + 366CD1 CB =10.571 0.429分配與傳遞計算分配系數(shù)固端彎矩0.4290.5710.5710.4290 -144144-2761.7882.22- 45.14分配與傳19.3725.771.58-3.682.100.13-0.300.17-0.0390.28- 67.8312.89-7.36-5.531.05-0.60-0.450.09-0.05-0.044

7、1.11最后彎矩82.86 - 82.89 100.85 - 100.85單位（ kN m）八、用力矩分配法計算圖示結(jié)構(gòu)，并繪出彎矩圖。各桿EI 相同且為常數(shù)。（10 分）解：梁的懸臂 DE 為一靜定部分，可求得 MDE =-36 kN?m，F(xiàn)QDE = 24kN 。將結(jié)點(diǎn) D 簡化為鉸支端，則 MDE 與 FQDE 應(yīng)作為外力作用于結(jié)點(diǎn)D 右側(cè)，因此可按下圖計算：24kN m24kN mB32kN 24kND 36kN6m 6m3m 3m計算分配系數(shù)SBABA =SBA +S BCEI46 0.5 EI EI4 + 466BC1 BA =10.5 0.5 =SCBCB =SCB +S CDE

8、I46 0.571 EI EI4 + 366CD 1 CB =10.571 0.429分配與傳遞計算分配系數(shù)710.429固點(diǎn)反力矩- 24固端彎矩- 183612123.436.855.15- 0.86- 1.72- 1.72- 0.86分 配 與 傳 遞0.250.490.37- 0.07- 0.13- 0.13- 0.070.020.040.03- 0.01- 0.01最后彎矩5.0710.1413.8412.45- 12.4536單位（ kN m）13.84M 圖（ kN m ）九、用力矩分配法計算圖示結(jié)構(gòu)，并繪出彎矩圖。各桿 EI 相同且為常數(shù)。32kN10kN/m

9、（10 分）10kNBA4m2m2m2m2m解：此剛架可按下圖計算：4m計算分配系數(shù)SBE4 EI0.571 = = = 4SBE +SBC 4iBE +3iBC 4 EI +3 EI 44BC 1 BE =1 0.571 0.429分配與傳遞計算 B固點(diǎn)反力矩20C BE分配系數(shù)0.4290.571固端彎矩- 142000分配與傳遞- 2.570- 3.43- 1.72最后彎矩- 16.5720- 3.43- 1.72E單位（ kN m）4）作 M 圖1.72 EM 圖（ kN m ）十、用力矩分配法計算圖示結(jié)構(gòu)，并繪出彎矩圖。各桿 EI 相同且為常數(shù)。（10 分）BA =+SBD+SBC解

10、：計算分配系數(shù)3 EIEIE4IEI 0.2733 EI + 4 EI 4 EI444BC =+SBC4 EI+SBDEI44 EI0.364 =SBD=BD = SBA +SBC +SBD = EIBA BC BD 34EI4 = = 4 CB = SCB +SCE =4 EI+4 EI 4SCBC E 1 C B= 1 0. 5分配與傳遞計算BA單位（ kN m）作M圖0.273EI44EI EI + 44440. 5BD0.3640.5BC0.3640.364CB0.520B- 10102.73- 3.64- 3.64- 1.82- 2.05- 4.09CE0.50.560.750.75

11、0.38- 0.10- 0.19- 0.190.030.040.040.02- 0.01- 0.0117.86- 2.85- 15.04.29- 4.29- 4.09DBEC- 1.82- 2.050.380.02- 1.42- 0.10- 2.1517.86scored two tries in the Kiwis' 20-18 semi-final win over England, has been passed fit after a lower-leg injury, while Slater has been named at full-back but is still

12、recovering from a knee injury aggravated against USA.Both sides boast 100% records heading into the encounter but Australia have not conceded a try since Josh Charnley's effort in their first pool match against England on the opening day.Aussie winger Jarryd Hayne is the competition's top tr

13、y scorer with nine, closely followed by Tuivasa-Sheck with eight.But it is recently named Rugby League International Federation player of the year Sonny Bill Williams who has attracted the most interest in the tournament so far.The Kiwi - with a tournament high 17 offloads - has the chance of becomi

14、ng the first player to win the World Cup in both rugby league and rugby union after triumphing with the All Blacks in 2011."I'd give every award back in a heartbeat just to get across the line this weekend," said Williams. The (lack of) air up thereWatch mCayman Islands-based Webb, the

15、 head of Fifa's anti-racism taskforce, is in London for the Football Association's 150th anniversary celebrations and will attend City's Premier League match at Chelsea on Sunday."I am going to be at the match tomorrow and I have asked to meet Yaya Toure," he told BBC Sport.&qu

16、ot;For me it's about how he felt and I would like to speak to him first to find out what his experience was."Uefa has opened disciplinary proceedings against CSKA for the "racist behaviour of their fans" duringCity's 2-1 win.Michel Platini, president of European football's

17、 governing body, has also ordered an immediate investigation into the referee's actions.CSKA said they were "surprised and disappointed" by Toure's complaint. In a statement the Russian side added: "We found no racist insults from fans ofCSKA."Baumgartner the disappointin

18、g news: Mission aborted.The supersonic descent could happen as early as Sunda.The weather plays an important role in this mission. Starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. The balloon, with capsule att

19、ached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. It will climb higher than the tip of Mount Everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and int

20、o the stratosphere. As he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.The balloon will slowly drift to the edge of space at 120,000 feet (Then, I would assume, he will slowly step out onto something resembling an Olympic diving platform.They blew it in 2008 wh

21、en they got caught cold in the final and they will not make the same mistake against the Kiwis in Manchester.Five years ago they cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by England's Josh Charnley in the opening game of the tournament.That could be classed as a weakness, a team under-cooked - but I have been impressed by the Kangaroos' focus in their games since then.They have been concentrating on the sort of stuff that wins you tough, even contests - strong defence, especially on their own goal-line, completin