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| Plastic Deformation | ||||||||||||||||||
| Drawing Wire | ||||||||||||||||||
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The
fabrication of wire to be used in bicycle spokes involves a drawing process
in which the cross section of the stainless
steel material is reduced to the required diameter by forcing it through
a series of dies. One step of this process is illustrated.
· The inset on the diagram shows the stresses acting on an element of the steel. |
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| From:
McMahon and Graham,
"The Bicycle and the Walkman," Merion (1992) |
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| ·
For
the plastic
deformation process, the maximum shear stress is desired. In this drawing
configuration the wire is under longitudinal tensile and lateral compressive
stress.
· For an isotropic material (small grain size) the maximum shear stress is: τmax = (σx + sy )/2 , where x is the tensile direction. |
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