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HMMWV High Mobility Multipurpose Wheeled Vehicle

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HMMWV High Mobility Multipurpose Wheeled Vehicle Powered By Docstoc
					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                                             0                                                C
CSuspension                                                                                 CSuspensionR
                                        TF    ZeroJunction2
                                                              TF
    1           0            1          TF1
                                                              TF2          1      0                1
           ZeroJunction1 OneJunction2
OneJunction1
                                                                              ZeroJunction3 OneJunction4
                                                                    OneJunction3


    R                                             0
                                              ZeroJunction4                      MSf               R
RBDampingF    MSf
                                                                                 MSf2           RBDampingR
              MSf1
                                                 TF
                                                  TF3


                                 Se               1                    I
          SignalGenerator1       Se1          OneJunction5                   SignalGenerator2
                                                                    I2momentofI
                        Modified Model
                                                      I
                                                 I1vehiclemass


    C                                                                                             C
                                                      0
CSuspension                                                                                   CSuspensionR
                                        TF       ZeroJunction2
                                                                 TF
    1           0           1           TF1
                                                                 TF2           1     0             1
           ZeroJunction1 OneJunction2
OneJunction1
                                                                                 ZeroJunction3 OneJunction4
                                                                       OneJunction3

                                                      0
    R
RBDampingF    MSe                                ZeroJunction4                                    R
              MSe1                                                                             RBDampingR
                                                     TF
                                                     TF3


                                                      1                    I
     SignalGenerator1                            OneJunction5          I2momentofI




                                                 
                                              Integrate1
                Test Results
                            model

                                                            output {rad}
0.015




 0.01



                      Force=6KN-9KN
                      Radians of Rotation = .00787-.01189
0.005




   0




        0   2     4                   6          8              10
                           time {s}
        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      0.6       0.8         1
Max Radians Before Rolling    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
                                                 0.012
  Radial Rotation needed to flip Vehicle (rad)




                                                  0.01




                                                 0.008




                                                 0.006




                                                 0.004




                                                 0.002




                                                    0
                                                         0          0.2       0.4           0.6           0.8   1          1.2
                                                                              Height of Center of Gravity (m)
                  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
   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
   <Ulrich.kramer@fh-bieldfeld.de> 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>