2 1. , . , .
( 1-10) 2.4 2.5. . , .. , .
:
1. ( , , () ).
2. , ( ).
3. , .
4. WX = Mmax / R.
5. .
6.
τmax = Qmax Sx / Jxb.
1. , = 2/3. . R = 130 M, RS = 10 M. ( 9)
:
F=20kH |
BF |
2,4 |
x = 2,6 |
1 |
5 |
1 |
VA=46kH |
M, kH*m |
Q, kH |
13,8 |
22,5 |
q=10kH/ |
-- |
-- |
-- |
VB=10kH |
m=15kH* |
D |
. 9
1. :
∑mA = 0;
-F *1 + q * 5 * 2,5 + m VB * 5 = 0;
∑mB = 0;
-F *6 + VA * 5 -q * 5 * 2,5 + m = 0;
X = 0; HA = 0,
:
∑ Y = 0;
VA + VB q * 5 F = 0;
46 + 24 - 50 20 = 0.
2. Q ( ):
QC = 0;
Q = Q = - F = - 20 (kH);
QA = - F + VA = -20 + 46 = 26 (kH);
Q = - F + VA q * 5 = - 20 +46 50 = -24 (kH);
Q = - F + VA q * 5 + VB = - 24 +24 = 0;
QK = - F + VA q * x = 0 → x = = 2,6 ().
3. ( ):
z = 0 → MC = 0;
z = 1 → MA = - F * 1 = -20 (kH*);
z = 3,6 → MK = -F * 3,6 + VA * 2,6 q *2,6 *1,3 = -20 * 3,6 +46 * 2,6 10 * 2,6 * 1,3 = 13,8 (kH*);
z = 6 → MB = -F * 6 + VA * 5 q * 5 * 2,5 = -20 * 6 +46 * 5 10 *5 *2,5 =
- 15(kH*);
z = 7 ( ) → MD = - m = -15 (kH*).
|
|
4. :
5. , , .
b =
6. :
max =
: b = 16 , h = 24 .
( 11- 20) 3.5. , . .
:
1. :
= 3
,
.
2. - . .
3. , .
4. - .
5. .
2. X QX - (. 10).
: , .
) |
M (kH*) |
22,5 |
RB |
) |
RA |
L1 =5 |
F=18kH |
-- |
-- |
Q (kH) |
) |
-- |
M (kH*) |
III |
II |
I |
D |
2,0 |
L |
Q (kH) |
32,6 |
17,4 |
27,4 |
22,5 |
7,5 |
7,5 |
A |
3,0 |
1,0 |
5,0 |
2,5 |
2,5 |
A |
F=18kH |
L |
) |
) |
) |
15,2 |
22,5 |
q=10kH/ |
) |
-- |
-- |
-- |
-- |
. 10 .11
1. I (. 11)
--- RA = RB = F/2 = 9 kH;
--- QA = RA = 9 kH( );
Q F = RA= 9 kH; Q F = RA F = 9 18 = -9 kH;
QB = RB = 9 kH ( );
--- .
Mx = F11/4 = 18*5/4 = 22,5 kHm; MA = 0;
MB = 0.
Mx Qx (. 11)
Fq |
32,6 |
M (kH*) |
15,2 |
RB=9 kH |
q=10kH/ |
) |
B |
RD |
Rc |
1,5 |
3,5 |
5,0 |
C |
D |
17,4 |
2,0 |
) |
-- |
-- |
-- |
Q (kH) |
) |
Rc |
L |
D |
1,5 |
17,4 |
22,5 |
27,4 |
) |
) |
1,0 |
E |
RE |
3,0 |
q=10kH/ |
RD=17,4 kH |
M (kH*) |
-- |
-- |
-- |
Q (kH) |
) |
. 12 .13
2. II I, RB (. 12).
---
∑ = - RB * 2 + q * 7 * 1,5 RD * 5 = 0;
|
|
RD = (-RB * 2 + q * 7 * 1,5) / 5 = 17,4 kH;
∑D = - RB * 7 - q * 7 * 3,5 + RC * 5 = 0;
RC = (RB * 7 + q * 7 * 3,5) / 5 = 61,6 kH.
∑Y = - RB + RC q * 7 + RD = - 9 + 61,5 70 + 17,6 = 0.
---
: QB = - RB = - 9 kH;
QC = - RB q * 2 = - 9 - 20 = -29 kH;
QC = QC + RC = - 29 + 61,6 = 32,6 kH;
: QD = - RD = - 17,4 kH;
QC = QD + q * 5 = - 17,4 + 50 = 32,6 kH.
QX (. 12). , , .
: QK = - RB q (2+x) + RC = 0;
-9 10 (2+x) + 61,6 = 0;
10x = 32,6;
x = 3,26 .
---
: MB = 0; MC = - RB * 2 q * 2 * 1,0 = - 38 kH;
: MD = 0; MK = RD (5 x) q ((5 - x)2/2) = 15,2 kH;
(. 23).
3. III D II, RD(. 13).
---
∑E = - RD * 1 - q * 1 * 0,5 RL * 3 = 0;
RD = (-RD * 1 - q * 1 * 0,5) / 3 = - 7,5 kH;
∑L = - RD* 4 - q * 1 * 3,5 + RE * 3 = 0;
RE = (RD * 4 + q * 1 * 3,5) / 3 = 34,9 kH.
∑Y = RL + RE q * 1 - RD = - 17,4 - 10 + 34,9 - 7,5 = 0.
---
: QD = - RD = - 17,4 kH;
QE = - QD q * 1 = - 17,4 - 10 = -27,4 kH;
QE = QE + RE = -27,4 + 34,9 = 7,5 kH;
: QL = - RL = - (-7,5) = 7,5 kH;
QX (. 13).
---
: MD = 0;
:ML = 0; ME = RL * 3 = - 22,5 kH.
(. 13).
MX QX , , , (. 10).
( 21- 30) 3.5. , . , .
:
1. . ( ).
2. , , .
3. .
: , , , , . , . , .
, , ( , ).
, , , , , . , .
|
|
, , , .
Q, M N :
1. .
2. .
3. Q , . .
4. . .
5. N . N .
6. .
3. , Q N. .
: Q. . , , .
D |
2 |
2 |
l = 4 |
A |
F = 5 kH |
q = 2kH/ |
) |
4 |
A |
Q (kH) |
9 |
9 |
) |
) |
) |
9 |
9 |
N (kH) |
M (kH*) |
4 |
22 |
22 |
A |
N |
Q |
22 |
a) |
. 14
. . ( ).
QB = 0;
QD = q (1/2) = 4 kH;
QD = QD + f = 9 kH;
Q = QD =9 kH/
. , : Q=0; QA = 0. . (. 14) , , . . .
(. 14 ). ( ).
. MB = 0;
MD = -q (12/8) = - 4 kH m;
MC = -F1 / 2 q *1/2 *3/41 = - 22 kH m.
. , 900, . , = = 2 22 kH m. , F Q , . = = - 22 kH m. ( ) .
N (. 12). , , , . , NCB = 0, , . , F 2q. NCA = - F 2q = - 9 kH. . , N, , .
|
|
. , , , .
, , , . QX, MX N, , (. 14).
QX , . ( ), Q . .
MX , . , , ( ) . NCA , , .
:
∑Xi = 0; ∑Yi = 0; ∑MC = 0.
, , Y :
∑Xi = 0; ∑Yi = N Q = 9 - 9 = 0; ∑MC = = 22 - 22= 0.
. , .