Degarmo's Materials And Processes In Manufacturing
13th Edition
ISBN: 9781119492825
Author: Black, J. Temple, Kohser, Ronald A., Author.
Publisher: Wiley,
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Textbook Question
Chapter 3, Problem 4P
Polyethylene consists of fibrous molecules of covalently bonded atoms tangled and interacting like the fibers of a cotton ball. Weaker van der Waals forces act between the molecules with a strength that is inversely related to separation distance.
- What properties of polyethylene can be attributed to the covalent bonding?
- What properties are most likely the result of the weaker van der Waals forces?
- If we pull on the ends of a cotton ball, the cotton fibers go from a random arrangement to an array of somewhat aligned fibers. Assuming we get a similar response from deformed polyethylene, how might properties change? Why?
- Would the properties of the deformed polyethylene be isotropic or anisotropic?
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Question (3):
At a temperature of 5°C, 3 mm gap exists between two polymer bars and rigid support, as shown
in the (Fig.3). Bar (1) is 50 mm wide and 20 mm thick [E = 800 Mpa, a = 140 x 10-6/°C ].
Bar(2) is 75 mm wide and 25 mm thick [E = 2.7 Gpa, a = 67 x 10-6/°C]. The supports at A
and C are rigid. Determine the lowest temperature at which the 3mm gap is closed, the normal
sresses in the bars(1) & (2) and the normal strains in the bars (1) & (2).
3
Best wishes
Fig. 3
(1)
3-mm gap
50 mm
700 mm
2
B
75 mm
400 mm
(2)
C
Chapter 3 Solutions
Degarmo's Materials And Processes In Manufacturing
Ch. 3 - What enables us to control the properties and...Ch. 3 - Â What are the next levels of structure that are...Ch. 3 - Prob. 3RQCh. 3 - Prob. 4RQCh. 3 - Prob. 5RQCh. 3 - Prob. 6RQCh. 3 - What are the three types of primary bonds, and...Ch. 3 - What are some general characteristics of...Ch. 3 - Prob. 9RQCh. 3 - Prob. 10RQ
Ch. 3 - Prob. 11RQCh. 3 - Prob. 12RQCh. 3 - Prob. 13RQCh. 3 - What are some unique property features of...Ch. 3 - Prob. 15RQCh. 3 - Prob. 16RQCh. 3 - Prob. 17RQCh. 3 - What are some of the general characteristics of...Ch. 3 - Prob. 19RQCh. 3 - Prob. 20RQCh. 3 - Prob. 21RQCh. 3 - Prob. 22RQCh. 3 - Prob. 23RQCh. 3 - Prob. 24RQCh. 3 - What is a grain? A grain boundary?Ch. 3 - Prob. 26RQCh. 3 - What is implied by a low ASTM grain�size number?...Ch. 3 - Prob. 28RQCh. 3 - What is Poissons ratio, and under what conditions...Ch. 3 - What is plastic deformation?Ch. 3 - Why do metals retain their strength during plastic...Ch. 3 - Prob. 32RQCh. 3 - Prob. 33RQCh. 3 - What is a dislocation? Using the carpet analogy,...Ch. 3 - What is the difference between an edge dislocation...Ch. 3 - What are some of the common barriers to...Ch. 3 - Prob. 37RQCh. 3 - What is the mechanism (or mechanisms) responsible...Ch. 3 - Why is a fine grain size often desired in an...Ch. 3 - What is an anisotropic property? Why might...Ch. 3 - What is the difference between brittle fracture...Ch. 3 - How does a metal increase its internal energy...Ch. 3 - What is required in order to drive the...Ch. 3 - How might the lowest recrystallization temperature...Ch. 3 - In what ways can recrystallization be used to...Ch. 3 - What is the major distinguishing feature between...Ch. 3 - What is warm working?Ch. 3 - How can deformation and recrystallization improve...Ch. 3 - Why is grain growth usually undesirable?Ch. 3 - Prob. 50RQCh. 3 - As a result of their ionic or covalent bonding,...Ch. 3 - Prob. 52RQCh. 3 - Prob. 53RQCh. 3 - What is the difference between an intrinsic...Ch. 3 - What is required for electrical conductivity in...Ch. 3 - What is required for electrical conductivity in...Ch. 3 - Brass is an alloy of copper with a certain amount...Ch. 3 - It is not uncommon for processing operations to...Ch. 3 - Polyethylene consists of fibrous molecules of...Ch. 3 - Prob. 5P
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