Alamosa Canyon Bridge Test
Lab 1 - Introduction
Today’s Objectives:
Students will:
a) Understand my background in
vibrations
b) Understand the purpose of the lab
and project
c) Understand the labs from ES205
appropriate for this class
d) Load RT Pro on laptops
e) Load DIAMOND
Vibrations
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Rose-Hulman Institute of Technology
Mechanical Engineering
Enhancing Power Harvesting Using a
Tuned Auxiliary Structure
Link
Vibrations
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Rose-Hulman Institute of Technology
Mechanical Engineering
Hip arthroplasty involves several steps
Femoral Component Insertion Monitoring Using
Human Cadaveric Specimens
Hip Socket
Osteoarthritis
Femoral
Head
Femur
Andrew Crisman, Rose-Hulman Institute of Technology
Molly McCuskey, University of New Mexico
Nathanael Yoder, Harvey Mudd College
Phillip Cornwell, Rose-Hulman Institute of Technology
R. Michael Meneghini, St. Vincent Center for Joint Replacement
Vibrations
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Rose-Hulman Institute of Technology
Mechanical Engineering
LADSS
Source: www.webmd.com/DW/arthritis/aa14678.asp (Jul 2004)
Cadavers were recently tested at UCSD
A test structure was
constructed for the testing
simulated femurs
(sawbones)
In surgery clamps and
retractors are used
Vibrations
The surgeon used larger
incisions at UCSD
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
Total norm technique followed depth
measurements.
S pe c im e n1 L
10 0
80
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
90
80
70
70
60
60
50
50
40
40
30
30
20
20
10
0
S p ec im e n1 R
10 0
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
90
Percent
Data analysis was conducted using a
custom Matlab GUI.
Percent
LADSS
10
0
2
4
6
8
N u m b er of H it s
10
12
0
14
1
2
3
4
5
6
N u m b er of H it s
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
80
70
60
60
50
40
30
30
20
10
10
0
0
5
10
15
0
2
4
6
N u m b er of H it s
S p ec im e n3 R
12
14
16
10 0
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
90
80
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
90
80
70
70
60
60
Percent
Percent
8
10
N u m b er of H it s
S pe c im e n4 L
10 0
50
50
40
40
30
30
20
20
10
0
10
50
40
20
Vibrations
9
S ea t ed Int e rval
% To ta l N orm
% D is t an c e t o F ina l P o s it ion
90
70
Percent
Percent
80
Vibrations
8
10 0
90
0
7
S pe c im e n3 L
S pe c im e n2 L
10 0
10
Femoral Component Insertion
12
Monitoring Using Human Cadaveric Specimens
0
2
4
6
8
10
12
N u m b er of H it s
14
16
18
20
0
1
2
3
4
5
6
N u m b er of H it s
7
8
9
10
This project has two purposes
Compare the initial mechanical stability of six
different implant/bone peg interfaces
Initial Mechanical Stability of Cementless Porous
Titanium Patellar Components
August 2, 2007
• Cemented Control Group
• Cemented Metal Backed
• Cementless Hexagonal Peg
• Cementless Cylindrical Peg
• Cementless Peri Coated
• Loosened Peri Coated
R. Parker Eason, University of Maine
Noah Ledford, University of Missouri-Rolla
Tarisa Lerro, University of Wisconsin-Milwaukee
Image from Direct Healthcare International.
Phillip Cornwell, Rose-Hulman Institute of Technology
R. Michael Meneghini, St. Vincent Center for Joint Replacement
Philip Rae, Los Alamos National Laboratory
R. Ben Wilms,
Vibrations
Vibrations
14
Similar sample groups produced similar LVDT results
In the past, sometimes students thought of
Vibrations as a class in differential equations
First loading
180
Second loading
x = xc + x p = D1e −ζω t sin(ωd t + φ1 ) + Xsin (ωt − φ )
144424443 14243
Steady State Solutoin
Transiet Solution
F0
k
160
n
140
120
100
X=
80
(1 − r )
2 2
60
[M ]{&x&}+ [K ]{x} = {0}
+ (2ζr )2
40
1 + (2ζr )
20
ω 2 [M ]{X } = [K ]{X }
2
xss (t ) = Y
0
Cemented Control
Group
Cemented Metal
Backed
Cementless
Cylindrical Peg
Cementless Hex Peg
Cementless
Hydroxy-Apetite
Coated
Cemented
Cementless
Loosened HydroxyApetite Coated
(1 − r ) + (2ζr )
2 2
2
sin (ωt + φ 2 − φ)
d  ∂T  ∂T ∂V ∂R
+
+
= Qi
 −
dt  ∂q&i  ∂qi ∂qi ∂q&i
{x(t )} = [Φ ]{q(t )}
Loosened
Vibrations
Vibrations
15
[Φ]T [M ][Φ ] = [I ]
The purpose of this lab is to reinforce the classroom a
material and give you practical skills in exp. vibrations
so [Φ ] [K ][Φ ] = [Λ ]
T
We first look at SDOF systems
• Frequency response (SDOF)
ECP
Matlab
Accelerometers
J=
– One point at a time
– Swept sin
(
1 n
∑ H ( jωi ) model − H ( jωi ) exp
n i =1
2
)
• FRF calculated using Matlab (also TFestimate)
• System ID (½ power point, fminsearch, selecting frequency
band)
Cables
– Band limited random input (windowing, averaging)
2
10
2
We created a
testing kit
1.5
Reduction in
amplitude
1
0.5
Magnitude
Amplitude (cm)
Displacement (micrometers)
m&x& + cx& + kx = ky + cy&
m&x& + cx& + kx = f (t )
200
0
-0.5
1
10
-1
-1.5
Vibrations
-2
Photon
Instrumented hammer
Vibrations
0
0
10
20
30
40
Time (s)
50
60
70
80
10
1
2
3
4
5
Frequency (Hz)
6
7
8
We will then look at 2-DOF systems
We now move to using the Photon’s
• Frequency response (2-DOF)
1
– Individual peaks, both at once
10
0
10
Magnitude of FRF
Amplitude of Mass 1 (cm)
2
1.5
1
0.5
0
-0.5
-1
-1
10
-2
10
-1.5
-2
0
10
20
30
40
50
60
70
80
-3
10
0
1
2
3
Time (s)
4
5
Frequency (Hz)
6
7
8
1
10
raw data
best fit
0
Magnitude
10
• 4 channel
• 24 bit
• Used with your
own laptops
-1
10
-2
10
Vibrations
Vibrations
-3
10
0
1
Rose-Hulman
Institute
of Technology
2
3
4
5
6
7
Frequency Engineering
(Hz)
Mechanical
8
The RT-Pro software is very easy to use
Exporting
data
We use DIAMOND (written in Matlab)
for curve fitting and mode visualization
Type of
measurement
Frequency range and
number of points
You can
easily plot
inputs and
outputs
Channels and
calibration, triggering,
windowing
Start the test
Overload
and points
for modal
test
Vibrations
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
All the labs build up to a final project
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering
All the labs build up to a final project
Vibrations
Labs from ES205: Lab 3
Labs from ES205: Lab 1 and Lab 2
1.6
Experimental data
1.4
Theoretical results
1.2
1
0.8
0.6
0.4
0.2
0
0
Lab 1 – Response of 2nd order System
•
•
Lab 2 – System Identification
Using Simulink
Effect of changing m, c and k
•
Identifying ζ, ωn for 2nd order
system using log decrement
Vibrations
•
•
1
1.5
2
Parameter identification using log decrement
Parameter identification using performance index
Vibrations
J=
1
2
n
∑ (x
model
i
− xitest
)
n i =1Institute of Technology
Rose-Hulman
Mechanical Engineering
Rose-Hulman Institute of Technology
Mechanical Engineering
Labs from ES205: Lab 9
Load RT PRO
• Note the number of your Photon
• Save license key to hard disk
• Install the software (will also need to install the
driver)
• Use the impact hammer and accelerometer to see
if you are getting any data
• Load “Test1.prj ” and Test1.dat
Frequency response plots
(Bode plots)
Vibrations
0.5
Lab 3 – System Identification (step
response)
•
One frequency at a time
using a swept sin input
Vibrations
Rose-Hulman Institute
Technology
• ofTime
history
Mechanical Engineering
DIAMOND
• Written at LANL for modal analysis (and other things)
• Download (DIAMOND_2008.rar)
• Launch program by typing “diamond” at the Matlab
command line (after changing directories).
– Load geometry file: test_geom_2007.mat
– Load data file: test_data_2007.mat
– Plot data
• As you run this program please take note of errors, bugs,
problems, etc.
• Make sure the software is installed on everybody’s
computer
Vibrations
The lab in this class (still a bit tentative)
Description
Introduction, load software
Frequency response of a SDOF system
Frequency response of a SDOF system
Frequency response of a 2-DOF system
Introduction to DIAMOND, RT-Pro, Experimental modal
Lab 5
analysis (start plate test)
Lab 6 Modal test of a plate, experimental modal analysis
Lab 7 Begin project
Lab 8 Project time, 5 minute progress report and preliminary data
Lab 9 Project time
Lab 10 Project presentations
Lab 1
Lab 2
Lab 3
Lab 4
Vibrations
Rose-Hulman Institute of Technology
Mechanical Engineering