1、 FABO OW A W AOBW BO OW BW AA FFO AFBB O FWAOWAB FAFBWO FA FBFB FAAO W BOW AFA AB A A AECC CW W DD B BW B AF0C A CBFEA AFE FAA AC FDCF W DWDD B BCW BFFBB FBAFFA ACFA FCBBWB FB qA BFCA C BWAC D BWD F A C BD q FAWB qF AFA FBCA D BA C B W FCWFFDCBFB 1qA C BF FA DF W BFB A FD FA 拱 F B CFBA FWD A D A DB

2、AAF AC BDW B D BWC C FF B CA FBFAWD AFBD FDFFDFABFB C ACF AFAFFCBFBDCWBFBFBW A和 B AB BC CEF及 BCDBA APW B 2PF AB D FW1W2A C E F CB A O BD G CWFATFFA BWFFAFCCC AA B B PBC P FPB PFAFNF FB F B BW1FFW2 W1W2A F C A FF F CF F F FA AF D D FFC3C E F C BCE F CBAWFO BFFBFBBFC CGDAFW FCO BF CGD桿在CF1和F2CFF1 2A30

3、oF143 B CF2 Cy F1F CxF24F 0 F Fy 1 5sin60o F203F 0 F Fx 1 5Fcos60o 0F207 N F164 NAC與BC2-6ABC和DE座A和E4 FB C6 84 D6A E 取DEDEFDFD=FEDEFE取ABCF BFAD3D4DF3AFAFAFDFE1 5F 166.7 N2 3ABcA和BM Ml/2 l/3A B A Bl l M l/2B A lM l/2A BFlA FB5M 0 FBlM 0 FBMlFA FBMl M l/3A Bl FA FBM0 FBlM 0 FBMlFA FBMl FAl/2M BAlFBM0 F

4、Blcos M 0 FBMlcosFAFBMlcos AB求A和CaBaC3a MaA 取BCBCFBBCFC6FB FC 取AB BBMFA A M 02 M MaaM 0 FF 0.354 2 2 2a aB BFAFC0.354Ma 2A BC0.7D0.8 0.8 0.4q3A BC30o1 2 A B DC0.8 0.8 0.8 0.8 y2FACDBxFAy0.7FB70.8 0.8 0.4 AxyF0: F 0.40 x F 0.4 kN M(F)0: 20.80.51.60.40.7FA BF 0.26 kNB20 Fy0: F 20.5F BF 0 ABy q 3A BF C

5、 x 30oFAy 1 2 FBx Axy M33(F)0: F 22dxx 0 B 0F 0.33 kNF0: F 22dxF cos30o 0 y B0F 4.24 kNBF0: F F sin30o 0 x BF 2.12 kN ABD y FCA B Dx AyFB0.8 0.8 0.8 0.8x Axy Fx FAx08 M(F)0: 20dxx8F0.8 1.6202.40A B0F 21 kNBF0: 20dxFF 200y B0F 15 kNABAB b BAD ABb yFM AAFAy GB xGBxyFx0: -FFGsin 0Gsin Fy0: F GGcos 0F G

6、(1cos) MB(F)0: M F bGRGR0A M G(1cos )bA由AC和CDC DC MqA D CDB C y a M a q aa9DxC CxyM(F)0: -qdxx M F 2a0 aC D0F 5 kNDF0: F aqdxF 0 y C D0F 25 kNC ABCy qABFF B xA aadxCCx BxyMa qdxxF(F)0: FaB A0 CF 35 kNAF0: F qdxF Fa y A B C0F 80 kNBa 00 F F F F F1 F 2 取 F1 21 FN1 101Fx0 F FN10 FN1F 取 FN222Fx0 FN20 FN

7、20 FN max F 1 F 2FFR1 2F0 F 2F Fx0 FR RF 取1FFN11Fx0 F FN10 FN1F 取 2FN2FRFx20 FN2FR0 FN2FRF FN max F 1 2 3 1 2 3 取1 FN1111Fx0 2FN10 FN12 取 1 2FN21 2Fx0 23FN20 FN21 取 3FN33Fx0 3FN30 FN33 FN max3 kN 1 2 1 2 取1 FN11Fx0 21FN10 FN11 取 2FN22Fx0 1FN20 FN21 FN max1kN FNFx12FNF xF FN x FNx 12dmm與d1 2AB C1 300

8、 450 2AF AAB和ACyF 450300Fx AFFxFy0 F0 F0 F F F 00 013FAC2 2F 41.4kN F F 58.6kN31 31ABF 82.9MPaA1F 131.8MPaA212AFd S WF lB A12 450CAAB和ACyFF450 AxFFFFFAC 2F FABF F 50103 1AS1 d24160MPa d 20.0mmF 70.7103 A b2W210MPa b84.1mm 題F 由F14FAC2 2F F F31 31AB2FF31 160 F 154.5 1A1 d241F A22F31 F 1d24240 100 FF10

9、0 100100F FF50103 5 MPaQA 100100sbsF 50103 12.5 MPabA 40100bF與FBFF 1 2 1 2bsF1AFB40 80D450dB C 450 ABCF610B6D2FB F2 F2 2FF1 2 1 2cos450 35.4 kNB15F FB Q 2 d 15.0 mm1 Ad2 S4BF F b BA db d d 15 mma a a aM M M M 500 500 500 300 300 300 1 2M1 M 2取1T1 xM1Mx0 T1M 0 T1 M取T22x2Mx0 T20 T20 M MT 161 2MA1M2MxM

10、x0 M2M M 0 MA A M取1T1MA x1Mx0 MTA 10T1 MA M 取2T2 xM2Mx0 M T20T2MT Mmax1 2 3 1 2 3 取1T1x 1Mx0 2T10T12 取2T2x 217Mx0 21T20 T21取3T3 x3 Mx0 2T30 T32 T 2 kNmmax1 2 3 1 2 3取1T1x 1Mx0 1T10 T11 取1 2T2x 1 2Mx0 12T20 T23取1 2 3T3x 1 2 3Mx0 123T30 T30 T 3maxTMx18TMx MT xTx AAAAA I p32(D4 d4)2.356105 mm4 AT 11061

11、5 63.7 MPaAI 2.356105T 110620 84.9 MPaI 2.356105T 110610 42.4 MPaI 2.356105 題0192M 21106 1d3d311 d1M1d32 1106d32 d239.9 M 210632 18001800 103 0.5 d GI 80103d4 1 173.5 mmMGI1800 110632 1800 103 0.5 d 8010 d 3 42261.8 mm d173.5mm d261.8mm FAMe CCBAB (a) qFA C B A BCa b (c) (d) 取FAMFSA F MAF0 求C取CFCMCF

12、20FF MCFl2 求B B FAC BMBFFSB F MB Fl 求 MeC BARA RBRA RBM le 求A+取A+MeAMFRAFSARAM leMA Me 求C取CAMe CMCRAFFRAMe Ml A MeRAl Me2 2 求B取BFMBBRB21FRBM le MB0 求 FA C BRARBRAFbabRBFaab 求A+取A+AMA FFSA RAFbabMA0 求C取CACMRA FF RAFbabM RC Aa Fabab 求C+取C+ 求B -FFCR BFaB FabM R bab abC BB取BMFBRBFSBRBFaabMB0 求A+22取A+qMF

13、A CBl l l 2F q M q SA 2 2 2 4 8A 求C-取CFqM BCFql l l 2 M q 2 2 2 4 8C 求C+取C+FqM BCl l l 2F q M q 2 2 2 4 8C 求B-取B-FM BFSB0 MB0q FA C B A B l2 2 (c) (d) x1x2FC B23ARA RCRA F RC 2F FS1 F (0 x1l/2) M1 Fx1(0 x1 l/2)FS2F (l/2 x1l) M2Flx2 (l/2 x1l) FS FxFMx 2qA B x FS4 q(l4x) x l) qM x 1 4 2x x l)2 FS(+)x

14、M/(+) x/424 F 與F1 2K FF 1 2F2F1 C zKy M)x M7.5 kNmax 106M M 40W2 2Z 6 6KKM y M y 106 3 40803IZ M e + -FAMe CzCy yCA1y1A1 A2 A2 y2 (150( (150(25IzC150503 252003 (15050)(y 25) 2 (25200)(150 y )2212 12 C C1.028 mm4M(+)x(-)+ AMA(250 yCIzC)40106(25096) 60.4 MPa1.02108AM yACIzC4010696 37.6MPa1.02108 AMA(250 yCIzC)30106(25096) 45.3MPa1.02108FqbF qA BbR A RBRA3.75 kNm RB11.25 kNmM(+)x (-) 263.75106 3.751