, .
M 1, Q 1, N 1 , M 2, Q 2, N 2 . κ2, g2, e2 u 2, v 2, q2, 1.3:
dN 2/ dx = qx; ü
dQ 2/ dx = qy; ý (1.10¢)
dM 2/ dx = Q 2. þ
κ 2 = d q2/ dx; ü
g2 = q2 dv 2/ dx; ý (1.11¢)
e2 = du 2/ dx. þ
κ 2 = M 2/ EJ; ü
g2 = m Q 2/ GF; ý (1.12¢)
e2 = N 2/ EF. þ
, dx , , , (. 3.10, ).
M 1, Q 1, N 1 (. 3.10, ):
dA 12 = - N 1 u 2 + (N 1 + dN 1)(u 2 + du 2) + Q 1 v 2 (Q 1 + dQ 1)(v 2 + dv 2) - M 1q2 +
+ (M 1+ dM 1)(q2+ d q2) + qxdx (u 2 + du 2/2) + qydx (v 2 + dv 2/2) = - N 1 u 2 + N 1 u 2 + N 1 du 2 + +{ dN 1 u 2}+ dN 1 du 2 + Q 1 v 2 - Q 1 v 2 - Q 1 dv 2 -{ dQ 1 v 2} - dQ 1 dv 2 - M 1q2 + M 1q2 + M 1 d q2 + + { dM 1q2} + dM 1 d q2 + qxdx (u 2+ du 2/2) + qydx (v 2+ dv 2/2). (3.12)
θ2 |
v 2+ dv 2 |
dx |
u 2 |
M 1 + dM 1 |
N 1 + dN 1 |
Q 1 + dQ 1 |
dx |
M 1 1 |
N 1 1 |
Q 1 1 |
) |
) |
qydx |
qxdx |
v 2 |
u 2+ du 2 |
θ2+ d θ2 |
. 3.10
(3.12) (1.10) , :
dA 12 = N 1 du 2 { Q 1 dv 2} + M 1 d q2 { qx dxu 2}+ qx dxu 2 + qxdxdu 2/2 { qy dxv 2} +
+ qy dxv 2 + qydxdu 2/2 + Q 1 dx q2. (3.13)
, (1.11¢) , , :
dA 12 = N 1e2 dx + M 1κ 2 dx Q 1(q2 g2) dx + Q 1 dx q2 =
= (M 1κ 2 + Q 1g2 + N 1e2) dx. (3.14)
, (3.14) (1.12¢), ds:
dA 12 = (M 1 M 2/ EJ + m Q 1 Q 2/ GF + N 1 N 2/ EF) ds.
. :
W 12 = - A 12 = - Sò (M 1 M 2/ EJ + m Q 1 Q 2/ GF + N 1 N 2/ EF) ds. (3.15)
-
(3.15) i - .
: , i , , (. 3.11). , .
|
|
i' |
Pi =1 |
. 3.11
D ip i . 3.11, .
Mp, Qp, Np , `Mi, `Qi, `Ni .
:
A 12 = A 21,
A 21 = Pi ×D ip = 1×D ip = D ip,
A 12 = W 12,
(3.15) , -:
D ip = Sò (Mp`Mi / EJ + m Qp`Qi / GF + Np`Ni / EF) ds. (3.16)
, () i :
Mp, Qp, Np ;
`Mi, `Qi, `Ni ( ), i ;
(3.16).
, , (3.16) :
D ip = Sò (Mp`Mi / EJ) ds. (3.17)
, , :
D ip = ò (Np`Ni / EF) ds= S(Npk `Nik / EFk) lk, (3.18)
lk EFk k - .
1. (3.17) Mp `Mi : D ip = (Mp ´ `Mi).
2. , , .
3. (3.16) , , , . , , -, , -, (3.16) .
(3.17) , , , .
, `Mi -, [ a,b ], . , . 3.12, , : `Mi (x) = tga× x. (3.17) :
(Mp`Mi / EJ) dx = (tga/ EJ) x × Mp dx. (3.19)
. 3.12
w Mp:
w = d w = Mp dx,
, Oy :
Sy = xd w = w× xc,
(3.19) :
(tga/ EJ) x × Mp dx = (tga/ EJ) xd w= (tga/ EJ) xc ×w = (w yc)/ EJ,
|
|
yc = tga× xc.
(3.17), :
D ip = S (w kyck)/(EJk). (3.20)
, , , w yc , .
(3.20) (. 3.13), . , .
. 3.13
1. (3.20) Mp w . , .
2. (3.17) , :
= [ (b a)/6] { f (a) + 4 f [ (a + b)/2] + f (b)},
, f (x) .
, [ a, b ] `Mi , Mp , (3.17) :
D ip =S(lk /6 EJk) { Mp (ak)× `Mi (ak) +4 Mp [ (ak + bk)/2]× `Mi [ (ak + bk)/2] +Mp (bk) × `Mi (bk) }. (3.21)
Mp [ a, b ] , , , Mp (x).