:
∑ = -Fn × 47 + F t1× 70 + Y×140 = -2.05× 47 + 1,15 × 70 = 0.
Y = 0,11 .
:
∑ = -Fn×187+Ya×140 - F t1×70 = -2.05×187 +Y×140 1.15×70 = 0.
Y = 3.31 .
Y:
∑Y = Fn -YA + F t1 + Y = 2.05 3.31 +1.15 + 0.11 = 0.
XOZ.
:
∑A = -Ft ×70 + XB×140 = -3.16×70 + XB×140 = 0.
XB = 1.58 .
:
∑B= XA×140+F t×70=3.16×70 XA×140 = 0.
XA= 1.58 .
:
∑X = XA F t + XB = 1.58 3.16 + 1.58 = 0.
0 1:
Z = 123.5 ͷ.
Z, X, Y. Y :
= .
, .
, , . .
:
= = = 143,6 ͷ.
d = 40 , : WX = ≈ 0,1 ×d = 0,1×403 = 6400 3.
σ = / WX = = 22,43 /2 < [δ] = 60 /2.
= = = 154 ͷ.
WX = = = 9112,5 3.
σ = = 16,9 /2 < [σ] = 60 / 2.
, .
, , . :
, - .
Jp min=0,1×344=133633 4.
:
[ φ 0]=0,00250,0350 /, [ φ ]=0,152,00 /.
[ φ 0]=0,02 /.
0,0000115 /=0,016 / < [ φ 0]=0,02 /.
, .
( d):
.
d = 48 ,
d = 52 ,
d = 55 ,
d = 60 ,
d = 65 .
d = 55
|
|
211
:
d = 55 ,
D = 100 ,
= 21 ,
r =43,6 .
:
.
, , =10 .
:
a=0,5× l + l +0,5×=0,5×60+21+0,5×21=61,5 .
:
.
: l =2×69,5=139 .
, , Z, X, Y .
:
:
Fn = 2,05 , = - 60,
FX = Fn ×cos 60 o = 2,05 × 0,5 =1,025 ,
FY = Fn ×sin 60 o = 2,05 × 0,86 = 1,775 ,
Ft = 3,16 , Fr = 1,15 .