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2.PROBLEMS 4.31 |
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MACHINE DESIGNHOME WORKPERSONALLINKS |
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4.31 :
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Tha shaft shown in Figure P4.31 is 200 mm long between self-aligning bearings A and B. Belt forces are applied to a sheave in center ,as shown. The left end of the shaft is connected to a clutch by means of a flexible coupling . Nothing is attached to the ring end. | |||
a: |
Determine and make asketch showing the stresses acting on the top and side elements, T and S, location | |||||
| adjacent to sheave.(Neglect stress concentration.) | ||||||
b: |
Represent the states of stress at T and S with three-dimensional Mohr circles | |||||
c: |
At location S, show the orientation and stresses actiong on principal element ,and on a maximuum shear element | |||||
Known :
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A
shaft of given geometry is to a known combined loading
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Find : |
a.Determine and make asketch showing elements, T and S, location | |||||
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c.a maximuum shear element
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Assumption : |
La = 100 mm, Lb = 100 mm, F1 = 2000 N,F2 = 400N,r = 20 mm, L = 5 mm , | |||||
| Figure P4.31 | ||||||
Analysis :a |
Determine and make asketch showing elements, T and S, location | |||||
Analysis :C |
At location S,stresses actiong on principal element ,and on a maximuum shear element compute the driect stresses associated with loads | |||||
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| Pictures free body load diagrams | ||||||
| Shaft subjected to lond .For a solid 20 mm. diameter shaft: | ||||||
| A maximuum shear element s: | ||||||
Comments : |
In support of neglecting the transverse shear stress in to note that its maximum value at tha neutral bending axis of the 2 mm.diameter shaft is 4V/3A = (4)(2000)/(3)( p*(0.02)²/4 ) = 8.488MPa. | |||||
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