Question

A copper strip of 200 mm width and 300 mm thickness is to be rolled to a thickness of 295 mm. The roll of radius 300 mm rotates at 100 rpm. The average shear strength of the work material is 180 MPa. The roll strip contact length and the roll force are

• A. 15.8mm and 0.569 MN
• B. 18.97 mm, 0.683 MN
• C. 38.73 mm and 1.395 MN
• D. 38.73 mm and 2.09 MN

Answer 1

The correct option is C 38.73 mm and 1.395 MN

Given:

$h_i=300mm,h_f=295mm,R=300mm$

N = 100 rpm, ${\tau }_{avg}=180MPa,Width=200mm$

Roll strip contact length

$L_p=\sqrt{R\Delta h}$

= $\sqrt{300\times (300-295)}$

= $\sqrt{1500}=38.73mm$

Rolling Force = ${\tau }_{avg}\cdot L_p\times width$

= 1394274.005 N

= 1.394 MN