3.
4. (Ashby & Jones 1: 13.2) A large thick plate of steel is examined by X-ray methods, and found
to contain no detectable cracks. The equipment can detect a single edge-crack of depth a
= 5 mm or greater. The steel has a fracture toughness Kc of 40 MN m
1150
ME 382 HOMEWORK 6 SOLUTION
4
890
700
0.25
2.75
1. (a) As shown in the diagram, 0.25%2.75%.
(b) As shown in the diagram, the alloy should be held between 700 Cand 890 C.
2
ME 382 HOMEWORK 6 SOLUTION
500
2. After 100 hours
ME 382 HOMEWORK 10 SOLUTION
1.
(i)
ar =
680
C1
=
61 MPa
.15
Nf
(107 ). 15
max = 61 MPa < Y
Therefore, no yielding.
(ii)
max = 100 MPa < Y
Therefore, no yielding.
Nf = (
C1 1/.15
680 1/.15
)
=(
)
3.5 105 cycles
ar
100
(iii)
max = 50 + 100 = 150 MPa < Y
T
ME 382 Fall 2012
Homework 1
(Due on Friday, September 14th, 2012)
Question numbers are from third editions of the textbooks.
(available on reserve in the Engineering Library and online)
Answers given have generally been rounded, so you may get slightly di
ME 382 HOMEWORK 2 SOLUTION
1.
xx = 3.0 103
yy = 1.5 103
xy = 2.0 103
The strain gauges are on the free surface of a steel structure,
E = 196 GPa = 1.96 105 MPa
= 0.3
E
196
G=
=
75.38GPa
2(1 + )
2 (1 + 0.3)
Since this is free surface zz = 0, xz = yz = 0
ME 382 HOMEWORK 2 SOLUTION
1.
xx = 3.0 103
yy = 1.5 103
xy = 2.0 103
The strain gauges are on the free surface of a steel structure,
E = 196 GPa = 1.96 105 MPa
= 0.3
E
196
G=
=
75.38GPa
2(1 + )
2 (1 + 0.3)
Since this is free surface zz = 0, xz = yz = 0
ME 382 HOMEWORK 2 SOLUTION
1.
xx = 3.0 103
yy = 1.5 103
xy = 2.0 103
The strain gauges are on the free surface of a steel structure,
E = 196 GPa = 1.96 105 MPa
= 0.3
E
196
G=
=
75.38GPa
2(1 + )
2 (1 + 0.3)
Since this is free surface zz = 0, xz = yz = 0
ME 382 Fall 2010 HW 9 Solutions
2.
Dowling 11.28.
For 7075-T6 aluminum, Y = 523 MPa, KIC = 29 MPam, and the Paris Law for
fatigue crack growth here is given by da/dN = 1.38 x 10-11K3.70 m/cycle, where
K is in MPam. You may assume that yielding does not oc
ME 382 Fall 2012
Homework 3
(Due on Friday, September 28th, 2012)
Question numbers are from third editions of the textbooks
(available online and on reserve in the Engineering Library)
Answers given have generally been rounded, so you may get slightly dif
ME 382 - Winter 2016
Homework 2
Due on January 22, 2016
The$questions$identified$with$*$are$intended$to$be$straight4forward$applications$of$what$has$
been$covered$in$class$or$required$background$from$ME211.$
The$answers$may$have$been$rounded.$
You will ne
ME 382 Fall 2012
Homework 6
(Due Friday, October 26, 2012)
The questions identified with * are intended to be straightforward applications or
review of what has been covered in class. Explain your answers, with ske
given
ME 382 HW1 Solutions
>
ME 382 HW1 Solutions
ME 382 HW1 Solutions
ME 382 HW1 Solutions
ME 382 HW1 Solutions
is shown as follows:
ME 382 HW1 Solutions
Note: Another solution provided from a separated pdf file
ME 382 HW1 Solutions
ME 382 HW1 Solutions
ME 382
Review: Midterm 2
March 23, 2016
Exam Seating (by last names):
Abrash-Haria: IOE 1680
Ho - Zeng: GGB 2505
*Starts at
10:40*
(worth 25%, same
as MT1)
Please bring:
Unmarked copy of databook (get
familiar with it before the exa
Lecture 03 - ME211 Review
ME 211 Review
Stresses
Stress is a second-order tensor:
#Ti
#A i $ 0 # A j
"ij = Lim
!
where dTi is traction in i direction on j face
!
#" " " & #" ) ) &
% xx xy xz ( % xx xy xz (
"ij = %"yx "yy "yz ( = %) yx "yy ) yz (
%
( %
(
$
ME 382
Homework 10
ME
Winter
2014
Due382
April
11, 2016
Homework 12
Due on Friday, April 18, 2014
1*.
A 40% tin, 60% lead alloy solder wire of diameter 3.15 mm is subjected to creep at
room temperature by hanging weights from lengths of the wire. Length c
Problem 1:
(a) Derive an expression for the critical radius needed for the homogeneous nucleation of a
cylindrical precipitate (with circular basis of radius r and height h=Cr, where C is a
constant) of in a matrix of , in terms of the surface energy !" ,
ME 382 - Fall 2015
Homework 2
(Due on Friday, January 20, 2017)
The questions identified with * are intended to be more challenging / interesting
The answers may have been rounded.
1.
A set of strain gauges on the free surface of an elastic steel stru
ME 382
Lecture 02
September 11, 2015
Stiffness / strength / toughness
Tensile test
Yield strength, tensile strength, modulus
True stress & strain
Work hardening
Uniaxial tensile test to measure mechanical properties
1. Measure length and area
2
HW02 Solution
A: Strength of the attractive potential
B: Strength of the repulsive potential
m: Steepness of the attractive slope
n: Steepness of the repulsive slope
ME 382 Fall 2015
Homework 4
(Due Friday, February 3, 2017)
The questions identified with * are intended to be more challenging / interesting
The answers may have been rounded.
1.
Use the phase diagram for copper and platinum shown below to answer
this que
ME 382 Winter 2017
Homework 3
(Due on Friday, January 27th, 2017)
1. It is possible to measure the density of a material to a high degree of accuracy (4
significant figures). A sample of aluminum cooled rapidly from a temperature just below
the melting po
Phase Diagrams
a Review
Topic 2
Review of
Phase Transformation
Diagrams
Solution and Solubility
Example: Solubility of salt in water
There exists a maximum amount of salt that can be
completely dissolved in water; excess of salt stays as solid.
This maxim
HW03 Solution
(a) A substitutional solute atom is a different atom that
occupies a site of the host atom. An interstitial solute
atom is an atom (can be any type of atom) that
occupies a site in the crystal structure at which there is
usually not an atom.
ME 382 - Winter 2017
Homework 1
(Due at the beginning of class on Friday, January 13th, 2017)
Tensile test questions (Lecture 2)
1.
The relationship between the true stress and the true strain for a metal
wire deforming at constant volume is of the form s
HW04 Solution
The complete solubility indicates that Cu and Pt have the same crystal structure.
( It's sufficient to say they are of the same structure. In this case, Cu has FCC
structure, so Pt must also have FCC structure.
The statement is false.
The
ME 382
Lecture 14
February 6, 2017
Introduction to kinetics
Mobility
Diffusion
Fick's Law
Rate of phase changes
Temperature-Time-Transformation (TTT) diagrams
Critical cooling rate
Gibbs free energy
G= H enthalpy
T
S
H = U + pV
absolute entropy
temperatur
Lecture 10 - Yield criteria
YIELD CRITERIA
Yield is a shear driven process
In general, material failure criteria compare
(i) a loading parameter - calculated from mechanics (ME211)
to a
(ii) a material parameter - measured by experiments (in data books)
F
ME 382
Lecture 04
January11, 2017
Relationship between stress and strain
3-D Hookes Law
Isotropic materials
Orthotropic materials
Stress and strain are second-order tensors .
Linear-elastic, isotropic materials
Young's modulus:
E (Pa)
Poissons ratio:
n
Sh
ME 382
Lecture 07
January 20, 2017
Defects in crystals
Point defects: vacancies, subsitutional, interstitial
Volume defects: voids, precipitates and second phases
Area defects: cracks, grain boundaries, phase boundaries
Line defects: edge and screw disloc
Lecture 01 - Introduction
Pre-requisite knowledge from ME211
In ME211, you learnt how to calculate the 3-D stress state in structures. This is a prerequisite step for many problems you will see in ME382. In particular, students who are
not confident with