Ex 3 MLE (Extrusion with friction).

The diagram below shows the slip-line field for a plane strain extrusion with a

constant shear stress along the die wall. The initial dimensions of the slab are: thick

mm60H and width mm50w . The material yield stress in pure shear is MPa20k . The ram velocity is smm6V0 .

0

H/2

h/2

V B

O

extp

D

A

C

Ram Metal

eV

45

30

45

f

p30

a) Identify the and lines. b) Draw the Mohrs circle diagram for the state of stress in triangle [OCD].

Determine the valor of the shear stress and the normal pressure (p) acting along the die wall. Calculate the value of the friction factor m . c) Construct the hodograph and represent the streamlines.

d) Determine the power required for the operation.