03-02ChapGere.0017

# 03-02ChapGere.0017 - ≤ T 2 5(80 GPa(362.3 3 10 2 9 m...

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Problem 3.7-8 What is the maximum power that can be delivered by a hollow propeller shaft (outside diameter 50 mm, inside diameter 40 mm, and shear modulus of elasticity 80 GPa) turning at 600 rpm if the allowable shear stress is 100 MPa and the allowable rate of twist is 3.0°/m? Solution 3.7-8 Hollow propeller shaft 220 CHAPTER 3 Torsion d 2 5 50 mm d 1 5 40 mm G 5 80 GPa n 5 600 rpm B ASED UPON ALLOWABLE SHEAR STRESS 5 1449 N . m T 1 5 2(100 MPa)(362.3 3 10 2 9 m 4 ) 0.050 m t max 5 T 1 ( d 2 / 2) I P Ê T 1 5 2 t allow I P d 2 I P 5 p 32 ( d 2 4 2 d 1 4 ) 5 362.3 3 10 2 9 m 4 t allow 5 100 MPa Ê u allow 5 3.0 8 / m B ASED UPON ALLOWABLE RATE OF TWIST 3 S HEAR STRESS GOVERNS M AXIMUM POWER P max 5 91.0 kW Ê P 5 91,047 W P 5 2 p nT 60 5 2 p (600 rpm)(1449 N . m) 60 T allow 5 T 1 5 1449 N . m T 2 5 1517 N . m ¢ p 180 rad / degree
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Unformatted text preview: ≤ T 2 5 (80 GPa)(362.3 3 10 2 9 m 4 )(3.0 8 / m) u 5 T 2 GI P Ê T 2 5 GI P u allow Problem 3.7-9 A motor delivers 275 hp at 1000 rpm to the end of a shaft (see figure). The gears at B and C take out 125 and 150 hp, respectively. Determine the required diameter d of the shaft if the allowable shear stress is 7500 psi and the angle of twist between the motor and gear C is limited to 1.5°. (Assume G 5 11.5 3 10 6 psi, L 1 5 6 ft, and L 2 5 4 ft.) C B A d L 1 Motor L 2 A-PDF Split DEMO : Purchase from www.A-PDF.com to remove the watermark...
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