Page 242 - Marks Calculation for Machine Design

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January 4, 2005
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STRENGTH OF MACHINES
224
(s,0) (2s,0)
s
(3s/2)
t (2q ccw)

FIGURE 5.40 Connect points to find average stress (σ avg ).

In Fig. 5.41 the radius of Mohr’s circle will be half the axial stress, that is (σ/2).

Radius

(s,0) (2s,0)
s
(3s/2)

t (2q ccw)

FIGURE 5.41 Draw circle.
Where the circle crosses the (σ) axis on the right, locates the maximum principal stress
(σ 1 ), and where it crosses on the left, is the minimum principal stress (σ 2 ). For the biaxial
element, the maximum principal stress is (2σ) and the minimum principal stress is (σ).
This means the biaxial element, like the uniaxial element, is actually the principal stress
element. Also, the radius of the circle (R) is the maximum shear stress (τ max ) as shown in
Fig. 5.42.

(s/2)
(s,0) (2s,0)
s
s 2 (3s/2) s 1

t (2q ccw)

FIGURE 5.42 Principal stresses and radius of circle.