8-21. The offset link has a width of w ⫽ 200 mm and a
thickness of 40 mm. If the allowable normal stress is
␴allow ⫽ 75 MPa, determine the maximum load P that can
be applied to the cables.
482
480
492
490
8-45 The pliers are made from two steel parts pinned
together at A. If a smooth bolt is held in the jaws and a
gripping force of 50 N is applied at the handles,
determine the state of stress developed in the pliers at
points B and C. Here the cross section is rectangular,
having the dimensions shown in the figure.
3.5 mm
4 mm
50 N
2 mm
60 mm 50 N
60 mm
4 mm
4 mm
4 mm
35 mm
80 mm
50 mm
50 N
⫹⌺Fx ⫽ 0;
N ⫺ 50 sin 30° ⫽ 0;
N ⫽ 25 N
⫹⌺Fy ⫽ 0;
V ⫺ 50 cos 30° ⫽ 0;
V ⫽ 43.3 N
j⫹⌺MC ⫽ 0;
M ⫺ 50(60) ⫽ 0;
–⬘ ⫽ 2 mm
y
M ⫽ 3000 N · mm
A ⫽ 4 ⫻ 8 ⫽ 32 mm2
I⫽
1
(4)(83) ⫽ 170.67 mm4
12
QB ⫽ 0
QC ⫽ –y⬘A⬘ ⫽ (2)(4)(4) ⫽ 32 mm3
Point B:
B N
My 25 3000( 4)
69.53 MPa (T)
A
I
32
170.67
Ans
B VQ
0
It
Ans
Point C:
C N
My 25
0 0.78 MPa 0.78 MPa (C)
A
I
32
Ans
Shear Stress:
C 43.3(32)
VQ
2.03 MPa
170.67( 4)
It
Ans
500
498
8-57
511
509