3.22: Problem Set
Assigned: 5/4/04
Solutions will be provided
Problem 1.
The S-N curve for an elastic material is characterized by the Basquin relationship,
a = C N b , where C is a material constant, a is the stress amplitude, Nf is the number
f
of full
3.22 Mechanical Behavior of materials
PS8 Solution
Due: April, 27, 2004 (Tuesday) before class (10:00am)
1. Annealed copper have a dislocation density of approximately 10 8 cm 2 . Calculate the
total elastic strain energy for copper. Assume that the dislo
3.22 Mechanical Behavior of materials
PS8
Due: April, 27, 2004 (Tuesday) before class (10:00am)
1. Annealed copper have a dislocation density of approximately 10 8 cm 2 . Calculate the
total elastic strain energy for copper. Assume that the dislocations a
3.22 Mechanical Behavior of materials
PS6
Due: April, 6, 2004 (Tuesday) before class (10:00am)
1. The results of a creep test performed on a specimen of polyethylene at room
temperature are given in the following table with graph.
Time(hrs)
4
J(t)10
0
100
3.22 Mechanical Behavior of materials
PS7
Due: April, 13, 2004 (Tuesday) before class (10:00am)
1. A component is subjected to the stress state of
0
300 0
ij = 0 100 0 MPa
0
0 200
The yield stress of the material in uniaxial tension is 173 MPa.
(a) W
3.22 Mechanical Behavior of materials
PS5
Due: March, 30, 2004 (Tuesday) before class (10:00am)
1. (a) Derive the constitutive equation
+
1
E1
= E 2 + ( E1 + E 2 )
1
E1
for the standard linear solid shown below.
(b) For the model shown above find the ove
3.22 Mechanical Behavior of materials
PS4
Due: March, 9, 2004 (Tuesday) before class (10:00am)
1. For the case of an epoxy + 70 v/o (volume percent) S-glass long fiber composite, what
is the elastic modulus of the composite both parallel and perpendicular
3.22 Mechanical Behavior of materials
PS3
Due: March, 2, 2004 (Tuesday) before class (10:00am)
1. A sample of a material subjected to a compressive stress z is confined so that it cannot
deform in the y-direction, but deformation is permitted in the x-dir
3.22 Mechanical Behavior of materials
PS2
Due: February, 24, 2004 (Tuesday) before class (10:00am)
1. The components of displacement of the element are shown below.
(a) Find expression of u1 ( x1 , x 2 ) and u 2 ( x1 , x 2 ) from the above figure.
(b) Sho
3.22 Mechanical Behavior of materials
PS1
Due: February, 17, 2004 (Tuesday) 5:00PM Rm.4-217
1. (a) Show that the stress tensor is symmetric in the absence of body forces and
accelerations. Assume that the areas of the faces of the unit cube are small enou
3.22 Mechanical Behavior of materials
PS9
Due: May, 4, 2004 (Tuesday) before class (10:00am)
1. A turbine blade in a jet engine operates at a peak temperature of 700. Due to the high
speed rotation of the engine, during operation the blades are subjected