SKRIPTA RIJEÅ ENIH ZADATAKA IZ OTPORNOSTI MATERIJALA

15
Sile u štapovima :
( )
( )
( )
( )
kN
S
kN
S
F
F
F
S
S
S
S
l
A
E
l
A
E
S
S
l
A
E
l
A
E
S
A
E
l
S
A
E
l
S
A
E
l
S
l
A
E
l
S
l
l
l
l
S
l
S
Fl
M
D
C
C
D
D
c
A
4
,
353
;
9
,
58
38
,
0
2
6
1
5
12
sin
4
sin
3
1
1
6
2
5
2
6
10
2
3
3
5
20
2
sin
sin
2
sin
2
sin
2
sin
sin
;
sin
sin
2
2
3
2
3
1
1
0
3
1
sin
3
2
sin
0
1
2
2
2
1
2
1
2
1
2
1
2
1
2
2
2
1
1
1
2
2
2
2
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
1
=
=
→
=
⎟
⎠
⎞
⎜
⎝
⎛
+
=
+
=
⇒
⇒
→
=
⇒
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
⋅
=
=
→
=
⇒
=
∆
=
=
∆
=
=
→
=
=
−
−
→
=
∑
α
β
β
α
β
α
α
α
δ
β
β
δ
δ
δ
δ
δ
β
α
K
K
Dimenzioniranje :
cm
h
cm
b
cm
A
b
cn
b
h
b
A
cm
A
A
cm
d
cm
m
d
S
d
S
d
A
A
S
dop
dop
dop
74
,
27
87
,
13
87
,
13
2
8
,
384
2
8
,
384
2
8
,
384
48
,
38
10
10
7
6
06
,
0
10
12
10
4
,
353
4
4
4
2
2
2
2
2
1
2
7
3
1
1
1
1
2
1
1
1
1
1
=
=
=
=
=
⇒
=
=
⋅
=
=
⋅
=
=
=
→
=
≥
⋅
⋅
⋅
⋅
=
≥
→
≥
=
→
≤
=
π
πσ
σ
π
σ
σ
Kontrola napona :
MPa
MPa
A
S
MPa
MPa
A
S
dop
dop
6
53
,
1
10
87
,
13
2
10
9
,
58
120
84
,
91
4
10
7
10
4
,
353
2
4
2
3
2
2
2
1
4
2
3
1
1
1
=
≤
=
⋅
⋅
⋅
=
=
=
≤
=
⋅
⋅
=
=
−
−
σ
σ
σ
π
σ