Homework__1_Solutions

# Fundamentals of Modern Manufacturing: Materials, Processes, and Systems

This preview shows pages 1–2. Sign up to view the full content.

Homework #1: 10 problems @ 10 points each = 100 total available points Due on September 1st, 2009 at 5 PM through the course web site Problems: 3.1, 3.2, 3.3, 3.4, 3.7, 3.8, 3.20, 3.24, 3.30, 3.31 3.1 A tensile test uses a test specimen that has a gage length of 50 mm and an area = 200 mm 2 . During the test the specimen yields under a load of 98,000 N. The corresponding gage length = 50.23 mm. This is the 0.2 percent yield point. The maximum load = 168,000 N is reached at a gage length = 64.2 mm. Determine (a) yield strength, (b) modulus of elasticity, and (c) tensile strength. Solution : (a) Y = 98,000/200 = 490 MPa. (b) σ = E e Subtracting the 0.2% offset, e = (50.23 - 50.0)/50.0 - 0.002 = 0.0026 E = σ/ e = 490/0.0026 = 188.5 x 10 3 MPa. (c) TS = 168,000/200 = 840 MPa. 3.2 In Problem 3.1, fracture occurs at a gage length of 67.3 mm. (a) Determine the percent elongation. (b) If the specimen necked to an area = 92 mm 2 , determine the percent reduction in area. Solution : (a) EL = (67.3 - 50)/50 = 17.3/50 = 0.346 = 34.6% (b) AR = (200 - 92)/200 = 0.54 = 54% 3.3 A test specimen in a tensile test has a gage length of 2.0 in and an area = 0.5 in 2 . During the test the specimen yields under a load of 32,000 lb. The corresponding gage length = 2.0083 in. This is the 0.2 percent yield point. The maximum load = 60,000 lb is reached at a gage

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This document was uploaded on 12/07/2009.

### Page1 / 3

Homework__1_Solutions - Homework#1 10 problems 10 points...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online