1、 1 1-3 .1 1-5 .1 1-3 max =100MPa C 1-3 N F z M 200kN N 10 00 2 m) 040 0 m 100 . 0 ( Pa) 10 100 ( 2 1 2 1 5 6 max N = = = = . . A F m kN 33 3 m N 10 33 3 m) 100 0 ( N) 10 200 ( 6 1 6 1 ) 3 2 ( 3 3 N N = = = = = . . . h F h h F M z1-5 AB AD A BAD 1 2-1.1 2-3.2 2-5.2 2-7.3 2-9.4 2-10.4 2-15.5 2-16.6 2-
2、18.7 2-21.8 2-22.9 2-1 2-1 2-1 2-1 22-3 A=500mm 2 F=50kN m-m 2-3 100MPa Pa 10 00 1 m 10 500 N 10 50 8 2 6 3 = = = = . A F m-m o 50 = MPa 3 41 ) 50 ( cos MPa 100 cos 2 2 . = = = o MPa 2 49 ) 100 sin( MPa 50 2 sin 2 . = = = o MPa 100 max = = MPa 50 2 max = = 2-5 - E p s b 2-5 3 220GPa Pa 10 220 0.001
3、Pa 10 220 9 6 = = = E MPa 220 p MPa 240 s MPa 440 b % 7 . 29 2-6 - 2-6 d =10mm l =200mm F = 12kN F=20kN 2-6 1. kN 12 = F 152.8MPa Pa 10 528 1 m 0.010 N 10 12 4 8 2 2 3 = = = = . A F 2-6 % . . 22 0 0022 0 = = mm 44 0 m 10 4 4 0022 0 m) 200 0 ( 4 . . . . l l = = = = 0 = l 2. kN 20 = F 255MPa Pa 10 55
4、. 2 m 0.010 N 10 20 4 8 2 2 3 = = = = A F % . . 39 0 0039 0 = = mm 78 0 m 10 8 7 0039 0 m) 200 0 ( 4 . . . . l l = = = = 400364 0 e . = 00026 0 p . = 0.052mm m 10 5.2 00026 0 (0.200m) 5 p = = = = . l l 2-9 F F =32kN b =100mm = 15mm d =20mm 2-9 2 0 m) 100 0 m/( 020 0 . . . b / d = = , 42 2. K d b F )
5、 ( n = n max K = 64.5MPa Pa 10 45 6 0.015m 0.020) (0.100 N 10 32 42 2 ) ( 7 2 3 n max = = = = . . d b KF K 2-10 F F=36kN b 1 =90mm b 2 =60mm =10mm d =10mm R =12mm 2-10 1. 1111 0 0.090m m 010 . 0 1 . b d = = 56 2 1 . K 117MPa Pa 10 17 . 1 m 010 . 0 ) 010 . 0 090 . 0 ( N 10 36 6 . 2 ) ( 8 2 3 1 1 n 1
6、max 1 = = = = = d b F K K 2 1.5 0.060m m 090 . 0 2 1 = = = b b d D2 . 0 0.060m m 012 . 0 2 = = = b R d R 74 . 1 2 K 104MPa Pa 10 04 1 0.010m 0.060 N 10 36 74 1 8 2 3 2 2 n 2 max 2 = = = = = . . b F K K 3. MPa 117 max = 2-15 F B C A 2-15 1. AB BC N1 F N2 F B F F F F ctan sin N2 N1 = = 2. 6 F A F A ct
7、an sin 2 1 = = ) ctan sin2 2 ( F ctan cos sin 2 2 1 1 l Fl l F l A l A V + = + = + = 0 d d = V 0 1 cos 3 2 = 4 4 54 = o 2-16 F A C l 2-16 1. F F F sin 2 N2 N1 = = 2. F A A sin 2 2 1 = = Fl l F l A V sin2 cos 2 sin 2 1 1 = = = 7 0 d d = V 0 cos2 = o 45 = 2-18 F 1 F 2 B d F 1 =50kN F 2 =35.4kN =100MPa
8、 bs =240MPa 2-18 1. 0 = x F 0 = y F kN 25 cos45 2 1 = = o F F F BxkN 25 sin45 2 = = o F F By kN 4 35 kN 25 25 2 2 . F B = + = 2. 2 2 s d F A F B = = m 015 0 m 10 100 10 4 . 35 2 2 6 3 . F d B = = bs b bs d F d F B = = 8m 01475 0 m 10 240 010 0 10 4 35 6 3 bs . . . F d B = = 15mm m 015 . 0 = d 2-21 F
9、 = 45kN b =250mm =6MPa bs =10MPa =1MPa l h 2-21 2 ) h ( b F = 0.030m m 10 6 250 0 10 45 2 6 3 = = . b F h a 2 bs bs b F = mm 9 m 009 0 m 10 10 250 0 2 10 45 2 6 3 bs = = = . . b F b 2 bl F = mm 90 m 090 0 m 10 1 250 . 0 2 10 45 2 6 3 = = = . b F l m 009 0. = a 48mm m 048 0 m ) 009 . 0 2 030 . 0 ( =
10、= + . h 9 mm 9 mm 90 l mm 48 h 2-22 F d=20mm =160MPa =120MPa bs =340MPa 2-22 1. 2-22 4 / 3 N2 N1 F F F F = = ) ( 1 N1 1 d b F A F = = 432kN N 10 4.32 N 10 160 015 0 ) 020 0 200 0 ( ) ( 5 6 = = = . . - . d b F ) 2 ( 4 3 2 N2 2 d b F A F = = 512kN N 10 5.12 N 10 160 015 0 ) 040 0 200 0 ( 3 4 ) 2 ( 3 4
11、 5 6 = = = . . . d b F 2-22 2. 8 s F F = 10 8 4 2 s d F A F = = 302kN N 10 02 3 N 10 120 020 0 2 2 5 6 2 2 = = = . . d F 3 4 4bs b bs b = = = d F d F F FkN 408 N 10 08 . 4 N 10 340 0.020 0.015 4 4 5 6 bs = = = d F F kN 302 = F 1 3-2.1 3-4.2 3-5.2 3-7.3 3-8.4 3-10.6 3-11 .7 3-13.8 3-15.10 3-16.10 3-1
12、8.11 3-19.13 3-20.14 3-24.15 3-25.16 3-27.17 3-28.18 3-29.20 3-30.21 3-32.22 3-2 D=60mm d=20mm l = 400mm F = 200kN E = 80GPa =0.30 D V 1. D EA F D D EA F = = = = 0.0179mm m 10 79 . 1 m 020 . 0 060 0 ( 10 80 060 . 0 10 200 30 . 0 4 ) ( 4 5 2 2 9 3 2 2 = = = = = = . d D E FD EA FD D D 2. V ) 2 1 ( ) 1
13、 )( 1 ( ) ( ) ( 4 ) ( 2 2 2 V Al d d D D l l A l V + + + + = + + + = = 2 3 3 7 3 9 3 mm 400 m 10 00 4 ) 3 0 2 1 ( m 10 80 400 0 10 200 ) 2 1 ( ) 2 ( = = = = + = = . . . E Fl V V V V3-4 l =0.10mm F d 1= 8.0mm d 2= 6.8mm d 3 = 7.0mm l 1 =6.0mm l 2 =29mm l 3 =8mm E = 210GPa =500MPa 3-4 1. F F ) ( 4 ) (
14、 2 3 3 2 2 2 2 1 1 3 3 2 2 1 1 d l d l d l E F A l A l A l E F l + + = + + = kN 65 18 N 10 865 1 N ) 007 0 008 0 0068 0 029 0 008 0 006 0 ( 4 10 10 0 10 210 ) ( 4 4 2 2 2 3 9 2 3 3 2 2 2 2 1 1 . . . . . . . . . d l d l d l l E F = = + + = + + = 2. 514MPa Pa 10 14 5 m 0068 0 N 10 65 18 4 4 8 2 2 3 2
15、2 min max = = = = = . . . d F A F 2.6 5 3-5 A F 1 2 1 = 4.0 10 -4 2 = 2.0 10 -4 F 1 2 A 1 = A 2 =200mm 2 E 1 = E 2 =200GPa 3 3-5 1. 16kN N 10 6 1 N 10 200 10 0 4 10 200 4 6 4 9 1 1 1 N1 = = = = . . A E F 8kN N 10 8 N 10 200 10 0 2 10 200 3 6 4 9 2 2 2 N2 = = = = . A E F 2. F A 0 = x F 0 = y F 0 sin3
16、0 sin sin30 N1 N2 = + o o F F F (a) 0 cos cos30 cos30 N2 N1 = + F F F o o(b) F F F sin 2 N2 N1 = (c) F F F cos 2 ) ( 3 N2 N1 = + (d) (c) (d) 1925 0 10 ) 8 16 ( 3 10 ) 8 16 ( ) ( 3 tan 3 3 N2 N1 N2 N1 . F F F F = + = + = o o 9 10 89 10 . . = kN 2 21 N 10 2.12 N 89 10 sin 2 10 ) 8 16 ( 2sin 4 3 N2 N1
17、. . F F F = = = = o3-7 F f f = ky 2 k A E l 4 3-7 1. y F 3 d d 30 2kl y ky y f F l l y = = = 2. k F F y = 3 3 3 3 l F k F kl = = a 3. y N F 3 d d 30 20 N ky y ky y f F y y = = = 4. y dy EA y F d d N = EA kl y y EA k EA y F l l 12 d 3 d 40 30 N = = = b (a (b) EA Fl 4 = 3-8 l = 180mm O 1 O 2 =7.54 5 1
18、0 3 kg/m 3 = 40MPa E = 160GPa 3-8 1. n x x d x x A F 2 ) d ( d = x ) 4 ( 2 d ) ( 2 2 2 2 / 2 N x l A x x A x F l x = = (a) 0 = x 8 2 2 max N, l A F = 8 2 2 max N, max l A F = = s / 1 5 1144 sec 180 . 0 10 54 . 7 10 40 8 8 2 2 3 6 2 . l = = 2 m/s 1kg N 1 = r/min 10929 min 2 r 5 . 1144 60 2 60 = = = n
19、 2. (a) ) 4 ( 2 ) ( ) ( 2 2 2 N x l E EA x F x = = 6 x x l E x x l ll d 4 2 2 )d ( 2 2 2 2 / 0 2 / 0 2 = = m 10 160 12 180 . 0 5 . 1144 10 54 . 7 12 9 3 2 3 3 2 = = E l 0.030mm m 10 00 . 3 5 = = 2 m/s 1kg N 1 = 3-10 A W E x A(x) 3-10 x d 3-10 x 0 ) d ( ) d ( 2 = + + A x x A A A d d 2 x x A A = C x A
20、 ln 2 ln 2 2 + = 7 2 2 2 ) ( x Ce x A = (a) 3-10 C x ) ( ) ( 0 2 0 0 g R W R A x A R x = = = (b) (b) (a) 2 0 2 2 0 2 R e g R W C = (c) (c) (a) 2 ) ( 0 2 2 2 0 2 ) ( x R e g R W x A = 3-11 AB k F B 3-11 F AB ( 3-11) N F l 8 3-11 A ) 2 ( ) ( N N b a F b a F a F + = + + F F = N ) 2 ( b a y + = ) 2 ( )
21、( 2 1 b a b a a l y y + = + + = + = l y = (b) k y k l k F = = N k F k F y = = N3-13 ABC B F 1 2 E A 1 =320mm 2 A 2 =2 580mm 2 B C B A 3-13 1. 3-13a 9 F F F F ctan sin N2 N1 = = 3-13 2. 3-13b 2 2 2 2 N2 2 1 2 1 1 N1 1 ctan sin2 2 EA Fl EA l F l EA Fl EA l F l = = = ) ctan sin sin2 2 ( tan sin 2 2 1 2
22、 2 1 A A E Fl l l By + = + = 3. 0 d / d = By 0 csc ctan 2 sin 2 sin ) sin2 cos sin cos2 2 ( 2 2 2 2 2 1 = + A A 0 cos 2 cos sin cos 2 2 2 1 2 2 = + A A 0 ) cos 3 1 ( cos 2 2 2 3 1 = A A 2 1 A A 0 03125 4 cos 09375 12 cos 2 3 = + . . 564967 0 cos . = o 6 . 55 = 10 3-15 l A - 3-14b C 3-15 C y y gAy F = N y A F y d d N = = B n = n y A gAy y B ) ( ) d d ( = y y B g n n y d ) ( d = C B n l g y y B g n n l n n Cy ) 1 ( ) ( d ) ( 10 + = = + ) ( 3-16 BD 1 2 3 C F F = 20kN A=100mm 2 E = 200GPa