第17次作业: 8-1 M=EL+F-3kNmm -el=0.8kn m 2 W=102cm3,W,=16.lcm 3×1060.8×10° W102×10316.1×10 294+791=128.8MPa 8-5 F FN F=-21.65kN.M==1625kNm A=306cm2,W=185cm3 FM21.65×10316.25×10 185×10 708+874=949MPa(压应力) 8-7 Fx=16kN,M=16×0.14=224kNn F 6M 第18次作业: F Fe 4F 32F6 [ mEx A w nd2 nd3 -s[] -=140.5kN 4(d+32e) 8-16 52 F 4=2xx×0 0.3925kN M=F×0.8=0.314kNm,T=F×06=02355kNm M2+T232×0.3925×10° xx60(-a)s60→a=0.91185 60-54.7 =265mm 8-18第 17 次作业： 8-1 MPa W M W M W cm W cm k N m M F l k N m Fl M Fl y y z z z y z y 29.4 79.1 128.8 16.1 10 0.8 10 102 10 3 10 102 , 16.1 3 . , 0.8 . 2 3 6 3 6 max 3 3 2 1 1 = + =   +   = + = = = = + = = =  8-5 7.08 87.4 94.9 (压应力） 185 10 16.25 10 30.6 10 21.65 10 30.6 , 185 16.25 . 4 21.65 , 2 3 3 6 2 3 max 2 3 MPa W M A F A cm W cm k N m Fl F F k N M z N z N = + =   +   = + = = = = − = − = =  8-7 b mm ab M ab F F kN M kN m N N [ ], 86 6 16 , 16 0.14 2.24 . max 2 = +  = = =  =   第 18 次作业： 8-11 kN d e d F d Fe d F W Fe A F t 140.5 4( 32 ) [ ] [ ] [ ] 4 32 3 max 2 3 = + = = + = +        8-16 mm W M T M F k N m T F k N m F pA k N r 2.65 2 60 54.7 60 0.91185 60 (1 ) 32 0.3925 10 0.8 0.314 . , 0.6 0.2355 . 0.3925 4 0.5 2 3 4 2 2 6 3 2 = − =   =  −   = + = =  = =  = =  = =        8-18