電大土木工程力學(xué)(本)作業(yè)三答案小抄參考

1、作業(yè)三參考答案一、選擇題1a 2c 3d 4d 5a二、判斷題1 2 3 4 5三、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)。（10分）10kn/m4m6mabc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)abc1（2）寫出位移法方程如下：k111+ f1p= 0（3）計算系數(shù)k11及自由項f1p 令，則 iab =3i， ibc =2i作圖和mp圖如下：2i圖abc112i6i2imp圖（knm）abc k11 = 12i+2i =14i knm（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，得： （5）作m圖 abc19(20)1.91.9m圖（k

2、nm） 四、用位移法計算圖示剛架，并繪制彎矩圖。（10分）30kn/me4mabcd2ei4m4m2ei2eieieif2m15kn解： （1）選取基本結(jié)構(gòu)如下圖所示，1、2為基本未知量。eabcdf12基本結(jié)構(gòu)（2）寫出位移法方程如下： k111+ k122+ f1p= 0 k211+ k222+ f 2p= 0（3）計算系數(shù)及自由項 令，則 iab = ibc =2i， ibe = icf = i， icd=4 i 作圖、圖和mp圖如下：eabcdf1圖2i8i4i4i8i4i k11 = 8i+4i+8i =20i k21 =4i k21 = k12 =4ieabcdf1圖2i8i4i4

3、i k22 = 8i+4i=12ieabcdfmp圖（knm）403040 f1p =40 knm f2p =-30 knm（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，得： 20i1+ 4i2+40= 0 4i1 +12i2-30= 0解得： （5）作m圖eabcdfm圖（knm）50.73018.67.9(60)16.410.75.413.66.8五、用位移法計算圖示剛架，并繪出彎矩圖。（10分）eabcd2eileieieiflleiqq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)：eadleileiq選取基本結(jié)構(gòu)如圖所示，1為基本未知量。ead1基本結(jié)構(gòu)（2）寫出位

4、移法方程如下：k111+ f1p= 0（3）計算系數(shù)k11及自由項f1p 令，則 iad = ide =i作圖和mp圖如下：ead圖14i4i2i2i k11 = 4i+4i =8ieadf1pmp圖 （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，得： （5）作m圖 eadm圖由對稱性，得原結(jié)構(gòu)的m圖如下：eadm圖fbc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）18kn/m6mabcd6m6m6m18kn/mef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)：18kn/m6mab3m6meg選取基本結(jié)構(gòu)如圖所示，1為基本未知量。a

5、beg1（2）寫出位移法方程如下：k111+ f1p= 0（3）計算系數(shù)k11及自由項f1p 令，則 iab = ibe =i， ibg =2i作圖和mp圖如下：gabe圖12i2i4i4i2i k11 = 4i+4i +2i =10iabge54mp圖（knm）54 f1p = 54 knm（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，得： （5）作m圖 abge64.8m圖（knm）(81)32.421.610.810.8由對稱性，得原結(jié)構(gòu)的m圖如下：abe64.8m圖（knm）(81)32.421.610.810.8cdf21.664.8(81)32.410.8七、用力矩分配

6、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）48kn/mabcd6m6m3m24kn3m解：計算分配系數(shù)， 分配與傳遞計算0.429分配系數(shù)固端彎矩最后彎矩144單位（knm）-82.8982.86分配與傳遞0.57100-14461.780.090-100.85100.85-0.6000.4290.5710-2782.2241.11-67.83-90.28-45.1425.7719.3712.89-7.36-5.53-3.681.582.101.05-0.45-0.300.130.17-0.05-0.04-0.03作m圖。abcd82.86100.85(216)m圖（knm

7、）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）8kn/mabcd6m6m3m32kn3m3me24knm解：梁的懸臂 de 為一靜定部分，可求得 mde =-36knm，fqde = 24kn。將結(jié)點 d 簡化為鉸支端，則 mde 與 fqde 應(yīng)作為外力作用于結(jié)點 d 右側(cè)，因此可按下圖計算：abcd6m6m3m32kn3m24knm24kn36knm計算分配系數(shù) 分配與傳遞計算0.5分配系數(shù)固端彎矩最后彎矩單位（knm）5.07分配與傳遞0.50360120.04-12.4512.45-0.13360.4290.5710-186.853.43-1.720.4

8、90.370.25-0.86-0.010.02-0.07固點反力矩-24012665.15-1.72-0.86-0.13-0.070.03-0.0110.1413.84m圖（knm）(48)5.07abcde10.1413.8412.4536（4）作m圖九、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)。（10分）10kn/m10kn32kneabcd2m2m2m2m4m解：此剛架可按下圖計算：10kn32knebc2m2m4m20kn20knm20knm計算分配系數(shù) ebc分配系數(shù)固端彎矩最后彎矩單位（knm）2000.4290.5710-14-2.57固點反力矩0-3.43b

9、e分配與傳遞20-1.72-16.5720-3.43-1.72 分配與傳遞計算（4）作m圖16.57(32)1.7220eabcd203.43m圖（knm）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）10kn/m20kneabcd4m2m2m4m解：計算分配系數(shù) 分配與傳遞計算單位（knm）100.2730.5-10-2.7320eabcd0.3640.364babcbd0.5cbce-3.64-3.64-1.82-4.09-4.09-2.050.560.750.750.38-0.19-0.19-0.100.030.040.040.02-0.01-0.01db4

10、.29-4.29ec17.86-2.85-15.0-1.820.380.02-1.42-2.05-0.10-2.15作m圖eabcd17.86(20)4.29152.15m圖（knm）(20)4.292.851.42winger tuivasa-sheck, who scored 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 r

11、ecovering 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 charnleys effort in their first pool match against england on the opening day.aussie winger jarryd hayne is the competitions top try scorer wi

12、th 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 becoming the firs

13、t player to win the world cup in both rugby league and rugby union after triumphing with the all blacks in 2011.id give every award back in a heartbeat just to get across the line this weekend, said williams.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism t

14、askforce, is in london for the football associations 150th anniversary celebrations and will attend citys 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.for me its about how he felt and i would like to speak to

15、him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said

16、 they were surprised and disappointed by toures complaint. in a statement the russian side added: we found no racist insults from fans of cska. baumgartner the disappointing news: mission aborted.the supersonic descent could happen as early as sunda.the weather plays an important role in this missio

17、n. 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 attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day weather lives. it will climb h

18、igher 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 into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the balloon will s

19、lowly 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 when they got caught cold in the final and they will not make the same mistake against the kiwis in manchester.five years ago the

20、y cruised through to the final and so far history has repeated itself here - the last try they conceded was scored by englands 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, completing sets and a good kick-chase. theyve been