Transcript Habirah Mohd Rosli Gertude Profio Fall 08 Iowa State University  Composite protectors used as safety gear for motorcyclist  Focus on the rider knees  Build.

Habirah Mohd Rosli
Gertude Profio
Fall 08
Iowa State University
 Composite
protectors used as safety gear for
motorcyclist
 Focus on the rider knees
 Build and test the protector’s resistance
impact

Fiber orientation doesn’t matter(0o and 90o)

Impact testing
The mold based on shape and size of
manufactured child kneepad
 Used 6 plies of carbon fiber
 Different materials to cover the mold




Release film
Wax
Release spray
 Holes
on the mold filled in by epoxy
 Cured at room temperature as plastic mold
might be damaged in autoclave
 Based
on national standard for cycle safety
gear, the speed of impact test range between
13-23ft/s
 Vertical impact
 Impact for 200lb person

Adult kneepads expensive
•Testing was done at CNDE
using impact machine
• Due to equipment limitation
speed desired cannot be
achieved (max 23ft/s)
• 2 sets of testing
•Sample attached with
epoxy
•Sample attached with
tape
• Both composite and plastic
kneepad were tested
•We created fixtures out of wood to secure the kneepads on
the machine.
•We set an aluminum plate under the wood to keep the wood
from being broken during the test.
•Impact tester
-46.5 inch drop
-Failure test: 32.5 lb load
-Impact test: 8.4 lb load
Sample
Material
Kneepad
attached to
the wood
Wood
attached to
aluminum
plate
Load lb
1
Carbon
fiber
Epoxy
Tape
32.5
2
Plastic
Epoxy
Tape
32.5
3
Plastic
Tape
Tape
8.4
4
Carbon
fiber
Tape
Tape
8.4
5
Plastic
Tape
No Tape
8.4
Kneepad 1
90
2
1.5
80
1
70
0.5
0
Energy
50
Deflection
-0.5
40
-1
30
-1.5
20
-2
10
-2.5
0
0
10
20
30
40
-10
50
Time (ms)
carbon fiber, epoxy, 32.5lb
60
70
80
90
100
-3
-3.5
Deflection (in)
Energy (ft-lb)
60
Kneepad 2
90
2
80
1.5
70
1
60
Energy (ft-lb)
50
Deflection
0
40
Deflection (in)
0.5
Energy
-0.5
30
-1
20
-1.5
10
-2
0
0
10
20
30
-10
40
50
Time (ms)
Plastic, epoxy, 32.5lb
60
70
80
90
100
-2.5
Kneepad 3
30
1
25
0
20
Energy (ft-lb)
2
-1
Energy
Deflection
15
-2
10
-3
5
-4
0
-5
0
10
20
30
-5
40
50
Time (ms)
Plastic, tape, 8.4lb
60
70
80
90
100
-6
Deflection (in)
35
Kneepad 4
35
2
30
1
25
20
0
15
deflection
-1
10
5
-2
0
0
10
20
30
40
50
60
70
80
90
100
-3
-5
-10
Time ms
Carbon fiber, tape, 8.4lb
-4
deflection in
energy ft lbf
energy
Kneepad 5
35
2
1
30
0
25
20
deflection in
energy ft lbf
-1
-2
energy
deflection
-3
15
-4
10
-5
5
-6
0
-7
0
10
20
30
Plastic, no tape, 8.4lb
40
50
time ms
60
70
80
90
100
Results Overview
Kneepad
Peak Load (lb)
Deflection at
peak load (in)
Impact
velocity (ft/s)
1
3314.75
1.31
15.21
2
3877.93
1.36
15.3
3
2135.9
1.25
15.16
4
557.04
0.68
15.26
5
2921.39
1.29
15.21
Note: 1 and 2 carbon fiber;tape;32lb
3 and 5 plastic; 8.4lb
4 carbon fiber; 8.4lb
5 no tape; 8.4lb
Peak Contact Force (kN)
Damage
7.3
Split fracture of patella
8.9
Split femoral condolytes
Kneepad
Peak Contact Force (kN)
3
9.5 kN
4
2.5 kN
5
13 kN
 The
used of tape doesn’t affect the impact
testing results.
 Deflection is low for carbon fiber kneepad.
 Impact velocity is between the range of
recommended testing (~15ft/s)
 Test
the samples with different loads
 Increase the number of plies of carbon fiber
for making an adult kneepad mold and test
it.