Bending Analysis
In tension, compression and pure shear cases for
bodies with uniform crosssection, the stress in the
body is uniform
However, for bending, there is a spatial variation of
stress
Bending is a mode of deformation in which tensile and
com

Hookes Law:
Tying stress and strain together
Challenge: If we can measure
tissue deformation, can we predict
the applied shear and normal
stresses?
before:
after
Predicting applied shear and
normal stresses and forces from
deformation measurements
Generat

e combinations
onent selection
hout compromising
d with
MatrixMANDIBLE. The next generation
#3 Due March 26th for Section 1/March 27rh for Section 2
mandibleHomework
plating system.
previous
BIOENG 1630 University of Pittsburgh
rrect implant and
*Show all

Homework #4 Due April 2/3, 2014 in class
BIOENG
1630
University
of Pittsburgh
Homework
#5 Due
February
13, 2013
BIOENG 1630 University of Pittsburgh
*Show all work for full credit*
*Show all work for full credit*
Problem 1. Rupture of artery: The followin

Hookes Law:
Tying stress and strain together
Challenge: If we can measure
tissue deformation, can we predict
the applied shear and normal
stresses?
before:
after
Predicting applied shear and
normal stresses and forces from
deformation measurements
Generat

Homework #6 Due April 16/17, 2014 in class
BIOENG 1630 University of Pittsburgh
*Show all work for full credit*
1) The pin shown below will be used in a set of clamps for the mechanical testing of ligaments.
The diameter of the pin is 0.50 in.
For the loa

Homework #1 Due March 06, 2014
BIOENG 1630 University of Pittsburgh
*Show all work for full credit*
1) The stress-strain () diagram for a collagen fiber bundle from which a human tendon is
composed is shown.
a. If a segment of the Achilles tendon at A has

Stress Analysis
Recall: Stress depends on
cross-section A
magnitude of applied force F
Stress = F/A
F
F
Why bother any
further?
A
What about the direction of applied
force?
V
F
P
Force F resolved in normal
component P and tangential
component V
Normal st

Homework #5 Due April 9/10, 2014 in class
BIOENG 1630 University of Pittsburgh
*Show all work for full credit*
*You may use Matlab codes provided in Courseweb*
1. Recall the problem of rupture of artery (Problem 1, Homework 4). Assume that the artery is
l

Biomechanics I
Homework #2 Solution Key
Due: 1/23/2013
1a) Plot the stress-strain (-) diagram for a soft tissue specimen as used in Quiz 1. The data file is in the courseweb.
data = 880.`, 0.04`<, 80.`, 0.04`<, 80.03`, 0.04`<, 80.04999999999999999`, 0.05`

Bending Analysis
In tension, compression and pure shear cases for
bodies with uniform crosssection, the stress in the
body is uniform
However, for bending, there is a spatial variation of
stress
Bending is a mode of deformation in which tensile and
com

TODAY
Stress-strain curve as signature of material
Non-linear elasticity
Viscoelasticity
Biological examples
Stress-strain diagram for bone
Ultimatestrength
Yieldstrength
Hookeslaw
E
)
Elastic
region
Yo
un
gs
mo
du
lus
(E
Stress
Yieldpoint
Plastic
region

Failure Theory
General observations for stress
state
Planes on which normal stresses are maximum,
are called principal planes
Maximum (minimum) values of the normal
stresses are called principal stresses
Shear stress is zero on principal planes
Shear

Deformable body mechanics
Concepts of stress and strain
TODAY
What is deformation?
What is load?
Concepts of stress and strain
Elasticity, plasticity
How stress is related to strain?
Hookes law
Load and Deformation
When external and/or internal forces ar

Biomechanics I
Homework #4 Solution Key
Due Date: 2/6/2013
1) Fixation screws and plates: The following figure shows different types of fixtion plate and screw configurations for the
craniofacial skeleton. Let us consider the assembly with four screws. It

Homework #2 Due in class
March 19 (For Section 1)/ March 20 (For Section 2)
BIOENG
1630
University
of23,
Pittsburgh
Homework
#2 Due
January
2013
BIOENG 1630 University of Pittsburgh
*Show all work for full credit*
*Show all work for full credit*
1) a) Plo

Biomechanics I
Homework #1 Solution Key
Due Date: 1/16/2013
1) If a segment of the Achilles tendon at A has a length of 6.0 inches and an approximate cross-sectional area of
0.20 in2 , determine its elongation if the foot supports a load of 125 lb, which

Biomechanics I
Homework #4 Solution Key
Due Date: 4/2/2014
1) Rupture of artery: The following figure shows a typical artery along with the loads that are applied on it. The figure also
shows a small rectangular piece of material taken from a point in the