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Unformatted text preview: IE 215 HOMEWORK 7 Bulk Deformation Solutions 19.14. A cylindrical part is warm upset forged in an open die. The initial diameter is 45 mm and the initial height is 40 mm. The height after forging is 25 mm. The coefficient of friction at the diework interface is 0.20. The yield strength of the work material is 285 MPa, and its flow curve is defined by a strength coefficient of 600 MPa and a strainhardening exponent of 0.12. Determine the force in the operation (a) just as the yield point is reached (yield at strain = 0.002), (b) at a height of 35 mm, (c) at a height of 30 mm, and (d) at a height of 25 mm. Use of a spreadsheet calculator is recommended. Solution: (a) V = π D 2 L /4 = π (45) 2 (40)/4 = 63,617 mm 3 Given ε = 0.002, Y f = 600(0.002) 0.12 = 284.6 MPa, and h = 40  40(0.002) = 39.92 A = V/h = 63,617/39.92 = 1594 mm 2 K f = 1 + 0.4(0.2)(45)/39.92 = 1.09 F = 1.09(284.6)(1594) = 494,400 N (b) Given h = 35, ε = ln(40/35) = ln 1.143 = 0.1335 Y f = 600(0.1335) 0.12 = 471.2 MPa V = 63,617 mm 3...
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This note was uploaded on 01/24/2011 for the course IE 215 taught by Professor Groover during the Fall '08 term at Lehigh University .
 Fall '08
 Groover

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