Transcript HMMWV (High Mobility Multipurpose Wheeled Vehicle)

HMMWV Rollovers
Picture taken from: Google.com
By, Chantelle Korson
PROBLEM STATEMENT
HMMWV – not an armored vehicle
 Armor Kits (“up-armoring” or “hardening”)

– Added sand bags, metal sheets, and plywood

Increased Risks
– Extra shrapnel
– Added weight
– Overload the suspensions
– Rolling
 Extra weight (up-armoring kits)
 High Centers of Gravity
Types of Add-on Armor
Pictures taken from: http://www.defense-update.com
General Idea
Assumptions

Russian Testing
– “Steal Pot”
 Limit outside factors (ground density)

Averaged/Estimated Data
– Vehicle specs
– Center of Gravity
– Force of Explosion
Original Model
I
I1vehiclemass
C
C
0
CSuspension
1
TF
0
1
ZeroJunction2
TF1
CSuspensionR
TF
1
TF2
OneJunction1
ZeroJunction1 OneJunction2
0
1
OneJunction3
ZeroJunction3 OneJunction4
0
R
RBDampingF
MSf
ZeroJunction4
MSf
MSf2
MSf1
TF
TF3
Se
SignalGenerator1
Se1
1
OneJunction5
I
SignalGenerator2
I2momentofI
R
RBDampingR
Modified Model
I
I1vehiclemass
C
CSuspension
1
TF
0
1
ZeroJunction2
TF1
CSuspensionR
TF
1
TF2
OneJunction1
ZeroJunction1 OneJunction2
0
1
OneJunction3
ZeroJunction3 OneJunction4
0
R
RBDampingF
C
0
MSe
R
ZeroJunction4
RBDampingR
MSe1
TF
TF3
1
SignalGenerator1
OneJunction5

Integrate1
I
I2momentofI
Test Results
model
output {rad}
0.015
0.01
Force=6KN-9KN
Radians of Rotation = .00787-.01189
0.005
0
0
2
4
6
time {s}
8
10
Height of Center of Gravity vs.
Rolling Displacement
Height of Center of Gravity
.6m
.8m
1m
Max Radians of Rotation Before Rolling
0.0106
0.00933
0.00823
Max Degrees of Rotation Before Rolling
0.609
0.535
0.471
Max Meters of Rotation Before Rolling
1.317
1.154
1.02
Max Feet of Rotation Before Rolling
4.32
3.79
3.35
Max Rotation Calculation
Data From Simulation
Height of Center of Gravity
Max Radians Before Rolling
0.6
0.8
1
0.01064 0.00933 0.00823
Force
6KN
0.00787 0.00787 0.00787
7KN
0.00928 0.00915 0.00928
8KN
0.01061 0.01048 0.01061
9KN
0.01189
0.01181
0.01189
Height of Center of Gravity vs.
Radial Displacement
Height of Center of Gravity vs. Radail Displacement to Roll
Radial Rotation needed to flip Vehicle (rad)
0.012
0.01
0.008
0.006
0.004
0.002
0
0
0.2
0.4
0.6
0.8
Height of Center of Gravity (m)
1
1.2
Validation

Engineer from TARDEC
– “We’ve added enough armor to survive the
explosion, but now the problem is surviving
the rollover.”

Numerous Website and Publications
– Roll over problems with added armor
– Both while in motion and caused by
explosions
Plan/Problems/Modifications

Original Experiment Set Up
– Change in mass = not significant
change in rollover factors
– As mass increased vehicle became
safer

Simple Simulation
– Basic bugs
– MSe connected to zero junction
 Pulse effort with a continuous
displacement
Safercar.gov

SSF=T/2H
– T=Track Width
– H = Height of Center of
Gravity

Average .8m Height of
Center of Gravity
– Hummer SSF = 2.064
– = 5 Stars
References
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Afghanistan incident Report 2002
<http://www.vcdsforces.gc.ca/boi_jowz/00Native/Anx-HDRC_Preliminary_iltis_incident_report.pdf>
Mark D. Donahue. Implementation of an Active Suspension, Preview Controller for Improved Ride Comfort
University of California at Berkeley, 1998
<http://vehicle.berkeley.edu/publications/ASC/mddon_msthesis.pdf>
The Application of Bond-Graphs to Real-Time Simulation Modeling of Vehicle Dynamics 27 March. 2006
<[email protected]> and <http://autolabfh-bielefeld.de>
NATO STANAG 4569 2a to 3a. 30 March. 2006
<www.ssss.com>
Eagle Armored Vehicle, Up Armored HUMVEE, Up-Armored Humvee M1114, and Guardian Door Protection For
Humvee. 30 March. 2006
<http://www.defense-update.com>
AM General: Light Service Support Vehicle 26 March. 2006
<http://www.amgeneral.com/vehicles_lssv_prodectinfo.php>
Defense Link 30 March. 2006
<http://www.defenselink.mil/transcripts/2004/tr20041215-1801.html>
High Mobility Multipurpose Wheeled Vehicle 28 March. 2006
<http://en.wikipedia.org/wiki/Humvee>
Japan International Cooperation System February 2004
<http://Jics.or.jp/jigyou/kenkyu/pdf/3GeneralRequirement.pdf.>
ADVISOR: Advanced Vehicle Simulator 30 March. 2006
<http://www.iitedu/ipro326/research.html>
Bomb Shock Wave Estimation. 26 March. 2006
<http://www.makeitlouder.com/document_bombshockwaveestimation.html>
Safercar 29 March.2006
<http://www.safercar.gov>