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PROBLEM (9.26) A hollow shaft with outer diameter D and inner diameter d is acted upon by an
axial tensile load P, a torque T, and a bending moment M, as portrayed in Fig. P9.26. Use Mohr’s
circle to determine the principal stresses and the plane on which they act.
Given: D = 50 mm,
d = 30 mm,
P = 40 kN, T = 500 N ⋅ m,
M = 200 N ⋅ m
SOLUTION
M
M
T
P
P
T
A
A = π ( 25 2 − 152 ) = 1256.6 mm 2
σx =
A
τ=
P Mc
+
A I
J=
π
(254 − 154 ) = 534 × 103 mm 4
2
I = J 2 = 267 × 10 3 mm 4
Tc
J
500(25 × 10−3 )
= −23.4 MPa
τ =−
534 × 10−9
40 × 103
200(25 × 10−3 )
+
= 31.83 + 18.73 = 50.56 MPa
σx =
1256.6 × 10−6
267 ×10−9
τ
(MPa)
(50.56, 23.4)
2θp’
σ2
σ1
C
R
σ (MPa)
R = (25.28) 2 + (23.4) 2
= 34.45 MPa
σ ' = 25.28 MPa
σ'
tan 2θ p ' =
23.4
, θ p ' = 21.4o
25.28
σ 1 = 25.28 + 34.45 = 59.73 MPa
σ 2 = 25.28 − 34.45 = −9.17 MPa
21.4 ο
59.73 MPa
A
9.17 MPa
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