14_440_407Homework5

14_440_407Homework5 - Rutgers University School of...

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

View Full Document Right Arrow Icon
Rutgers University 14-440:407 School of Engineering Mechanical Properties of Materials Dept. of Materials Science & Engineering HOMEWORK #5 1. A specimen of a 4340 steel alloy having a plane strain fracture toughness of 50,000 psi in (54.8 MPa m ) is exposed to a stress of 150,000 psi (1030 MPa). Will this specimen experience fracture if it is known that the largest surface crack is 0.02 in. (0.5 mm) long? Why or why not? Assume that the parameter Y has a value of 1.0. 2. List four measures that may be taken to increase the resistance to fatigue of a metal alloy. 3. The following creep data were taken on an aluminum alloy at 480 ° C (900 ° F) and a constant stress of 400 psi (2.75 MPa). Plot the data as strain versus time, then determine the steady-state or minimum creep rate. Note: The initial and instantaneous strain is not included. Time (min) Strain Time (min) Strain 0 2 4 6 8 10 12 14 16 0.00 0.22 0.34 0.41 0.48 0.55 0.62 0.68 0.75 18 20 22 24 26 28 30 32 34 0.82 0.88 0.95 1.03 1.12 1.22 1.36 1.53 1.77
Background image of page 1

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

View Full DocumentRight Arrow Icon
1. This problem asks us to determine whether or not the 4340 steel alloy specimen will fracture when exposed to a stress of 150,000 psi, given the values of K
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

14_440_407Homework5 - Rutgers University School of...

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

View Full Document Right Arrow Icon
Ask a homework question - tutors are online