Chapter 1 Introduction
1.1 Overview
For several decades, the study of the dynamics of automobile occupants has become a
critical area of research. This is due to the high fatality and injury rate associated with
automobile accidents. A significant number of automobile fatalities and injures are
caused by severe impacts to vital body organs. To better understand such injures, there
is a need for computer simulation which can predict body segment motions under
various impact conditions. Such modeling procedures will also be useful in
developing better seat and restraining systems, and for improving interior and exterior
structural design.
A stimulus for the development of crash-victim models has been the rapid
development of computer hardware and software. Also, there have been significant
advances in numerical methods for modeling of multibody systems. A principal
application of multibody systems analysis is the simulation of the dynamics of the
human body. Currently there are at least ten distinct gross motion software simulators
available. These simulators differ primarily in the variety of input-output options
available. There is, of course, significant diversity among these software simulators
due to their inherent complexity.
During recent years there have been many attempts to develop efficient methods for
obtaining equations of motion for multibody systems. Most researchers have
formulated these equations using either Newton's laws, Lagrange's equations theory.
Each of these approaches has the objective of efficient development of
computer-oriented equations. The relative advantages (or disadvantages) of these
various approaches depend on the dynamical principle used and the method or
organizing the geometry. The difficulties encountered usually include (1) the
introduction of non-working constraint forces between adjoining bodies (as with
Newton's law); (2) lengthy involved differentiation of energy functions (like
Lagrange's equations); (3) the geometrical description of the system; and (4) the
solution of the governing equations in their developed form. The methods used in this
book to develop the crash-victim model combine Kane's equations theory (Lagrange's
form of d'Alembert's principle) with geometric and accounting procedures developed
by Huston and Passerello. By using these methods we can avoid above difficulties and
develop the governing equations of motion for a multibody system like a human body
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model in a vehicle frame.
1.2 Earlier Work
Computer simulation in crash-victim analysis dates back at least 27 years. Perhaps the
original study in this area was done by McHenry [1] in 1963. His software simulator
was a 7 degrees of freedom, two-dimensional model to simulate human response in
frontal automobile impacts. It used rods to simulate the human segments. In 1966
McHenry et al. expanded this model to include 11 degrees of freedom. Similar
expansions of McHenry's model was also made by Segal et al. (1967,1971) [2-5]. The
basic analytical formulation of the motion for this model was the Lagrangian method.
More recent two-dimensional models include those developed by Danforth and
Randall [6], Robbins, Bowman, and Bennett, et al. ("MVMA") [7], Glancy and
Larsen ("SIMULA") [8], Twigg, Karnes, Collins, et al. ("PROMETHEUS") [9-12],
Maltha, Wismans, et al. ("MADYMO") [13-15]. The "MVMA" model has 10 degrees
of freedom, and uses spheres to simulate the human frame. The equations of motion
of the model are derived using the Lagrangian technique. In the "SIMULA" model,
the masses are concentrated at the joints instead of at the segment mass centers. Rods
are used to simulate the human body segments and the Newtonian technique is used to
derive the equations of motion. "SIMULA" was modified by Twigg, et al. [10,11] and
then renamed "PROMETHEUS". The "MADYMO" model has an arbitrary number of
degrees of freedom [13]. It consists of pin-connected ellipsoids representing the
human frame. The Lagrangian method is used for the analytical formulation.
A number of three-dimensional software simulators have been developed. There are:
"HSRI", developed by Robbins, King, Patrick, et al. [16-21]; "TTI", developed by
Young [22-24]; "SOM-LA", developed by Laananen [25-28]; "CALSPAN",
developed by Bartz, Fleck, Karnes, et al. [29-34]; "MADYMO", developed by
Wismans, Maltha, et al. [13-15]; "UCIN-CRASH", developed by Huston et al.; and
“SuperCrash”, developed by Huang et al. [35-42]. The "HSRI" model has 6 mass
segments providing 17 degrees of freedom. The human joints are simulated by hinge
and ball-and-socket joints. The motion input is described by piecewise linear
functions for as many as 6 (3 linear, 3 angular) acceleration functions of the vehicle.
The governing equations are derived using Lagrange's method.
The "TTI" model contains 12 mass segments providing 31 degrees of freedom. As
with the "HSRI" model, it has both hinge and ball-and-socket joints to simulate the
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human joints. Also Lagrange's equations are used to develop the governing equations.
This model is designed for vehicle crashes where the vehicle displacement is known
as a function of time.
The "SOM-LA" model has 11 mass segments providing 28 degrees of freedom. Hinge
and ball-and-socket joints are used to simulate the human joints. The motion input is
described by 6 (3 linear, 3 angular) piecewise linear acceleration functions of the seat.
The governing equations are derived by Lagrange's technique.
The "CALSPAN" model has 15 mass segments. The human joints are simulated by
either a locked, hinged, or ball-and-socket joints. It may have as many as 63 degrees
of freedom. The motion input is through the vehicle with provision for 6 (3 linear, 3
angular) piecewise linear acceleration functions. The governing equations are derived
using Newton's laws.
The "MADYMO" model consists of an option of choosing the number of mass
segments simulating the human body. The human joints are simulated by both
spherical and hinge joints. The formulation is based on Lagrange's equations. The
"UCIN-CRASH" model contains 12 mass segments with 34 degrees of freedom. A
translation connection joint is used to simulate the neck joint. The hinge and
ball-and-socket joints are used to simulate the other joints. The motion input is
through the vehicle with provision for 6 (3 linear, 3 angular) piecewise-linear
acceleration functions. The governing equations are developed by the Kane's
equations.
1.3 Reference
[1] McHenry,R.R., "Analysis of the Dynamics of Automobile passenger Restraint
systems," Proceedings of the 7th Stapp Car Crash Conference, pp. 207-249, 1963.
[2] Mchenry,R.R., and Nabb,K.N., "Computer Simulation of the crash Victim - A
Validation Study," Proceedings of the 10th Stapp Car Crash Conference, Holloman
AFB,N.M., 1966.
[3] McHenry,R.R., Naab,K.N., et al, "Cal Computer Simulation Predicts Occupant
Responses During Vehicle Head-On Collision," SAE Journal, Vol. 75, No. 7,
July,1967, pp. 36-45.
[4] Segal,D.J., and McHenry,R.R., "Computer Simulation of Automobile Crash
Victim - revision No. 1," Cornell Aeronautical Laboratories, Inc., Report No.
VJ-2492-V-1, March, 1968.
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[5] Segal,D.J., "Revised Computer Simulation of the Automobile Crash Victim,"
Cornell Aeronautical Lab., Report No. VJ-2759-V-2, 1971.
[6] Danforth,J.P., and Randall,C.D., "Modified ROS Occupant Dynamics Simulation
User Manual," General Motors Corp. Research Labs., Publication No. GMR-1254,
1972.
[7] Robbins,D.H., Bowman,B.M., and Bennett,R.O., "The MVMA Two-Dimensional
Crash Victim Simulations," Proceedings of the 18th Stapp Car Crash Conference,
pp.657-678, 1974.
[8] Glancy,J.J., and Larsen,S.E., "User Guide for Program SIMULA," Dynamic
Science, Report TDR No. 72-23, 1972.
[9] Karnes,R.N., Sebastian,J.D., Tocher,J.L., and Twigg,D.W., "A User-Oriented
Program for Crash Dynamics," Proceedings of the International Conference on
Vehicle Structural Mechanics, Detroit, Mich., March, 1974, pp. 154-163.
[10] Twigg,D.W., and Karnes,R.N., "PROMETHEUS - A User-Oriented Program for
Human Crash Dynamics (User Manual)," ONR Contract N00014-72-C-0223, Report
No. BCS-40038, Nov. 1974.
[11] Karnes,R.N., Tocher,J.L., and Twigg,D.W., "PROMETHEUS - A Crash Victim
Simulator," Aircraft Crashworthiness, University Press of Virgina, 1975, pp. 327-345.
[12] Collins,J.A., and Turnbow,J.W., "Response of a Seat- Passenger System,"
Symposium on Dynamic Response of Structures, Stanford, CA., June, 1971.
[13] Maltha,J and Wismans,J., 1980. "MADYMO - crash victim simulations, a
computerized research and design tool," Ircobi Conference, Birmingham.
[14] Wismans,J., Maltha,J., Melvin,J.W. and Stalmaker,R.L., 1979. "Child restraint
evaluation by experimental and mathematical simulation," Proceedings of the 23rd
Stapp Car Crash Conference, Society of Automotive Engineers, Warrendale, Pa.
[15] Wismans,J., Cesari,D., Maltha,J. and Ramet,M., 1980. "Evaluation of the
experimental reconstruction of a real frontal collision with a mathematical model,"
Ircobi conference, Birmingham.
[16] Robbins,D.H., Bennett,R.O., and Bowman,B.M., "User-Oriented Mathematical
Crash Victim Simulator," Proceedings of the 16th Stapp Car Crash Conference,
Warrendale, Pa., 1972, pp.128-148.
[17] Robbins,D.H., Bennett,R.O., and Roberts,V.L., "HSRI Three-Dimensional Crash
Victim Simulator: Analysis Verification, Users Manual, and Pictorial Section," NTIS
No. PB 208 242, June 1971.
[18] Robbins,D.H., "Three-Dimensional Simulation of Advanced Automotive
Restraint System," Paper No. 700421, 1970. International Automobile Safety
Conference Compendium, P-30 SAE, warrendale, Pa., May, 1970, pp. 1008-1023.
[19] King,A.I., Chou,C.C., and Mackinder,J.A., "Mathematical Model of an Airbag
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for a Three-Dimensional Occupant Simulation," SAE Paper No. 720036, Warrendale,
Pa., Jan. 1971.
[20] Patrick,L.M., "Airbag Restraint for Automobile Drivers, Vol. II, Occupant
Simulation Model," Final Report on DOT Contract FH-11-7607 for NHTSA, Wayne
State University, Detroit, Mich., 1972.
[21] Robbins,D.H., Bennett,R.O., and Bowman,B.M., "HSRI Six-Mass,
Three-Dimensional Crash Victim Simulator," NTIS No. PB 239 476, Feb. 1973.
[22] Young,R.D., "A Three-Dimensional Mathematical Model of an Automobile
Passenger," Research Report 140-2, Texas Transportation Institute, Texas A&M
University, College Station, Tex. NTIS No. PB 197 159, Aug. 1970.
[23] Young,R.D., Rose,H.E., and Lammert,W.F., "Simulation of the Pedestrian During
Vehicle Impact," Proceedings of the 3rd International Congress on Automotive Safety,
Paper No. 27, Vol. 2, 1974.
[24] Young,R.D., "Vehicle Exteriors and Pedestrian Injury Prevention, Vol. V, A
Three-Dimensional Mathematical Simulation-Extension and Validation," Final
NHTSA Contract Report, Texas transportation Institute, College Station, Tex., 1975.
[25] Laamanen,D.H., "A Digit Simulation Technique for Crashworthy Analysis of
Aircraft Seats," SAE Paper No. 740371, Warrendale, Pa., April, 1974.
[26] Laananen,D.H., "Development of a Scientific Basis for Analysis of Aircraft
Seating Systems," Report No. FAA-NA-74-175, Ultrasystems, Inc., Dynamics
Science Div., Phoenix, Az., Jan., 1975.
[27] Laananen,D.H., "Implementation of a Digit Simulation Technique for
Crashworthy Analysis of Aircraft seats," Presentation 750541 at the SAE Business
aircraft Meeting, Wichita, Ka., April, 1975.
[28] Laananen,D.H., "Simulation of an Aircraft Seat and Occupant in a Crash
Environment," Aircraft Crashworthiness, University Press of Virginia, 1975, pp.
347-363.
[29] Bartz,J.A., "Development and Validation of a Computer Simulation of a Crash
Victim in Three Dimensions," Proceedings of the 16th Stapp Car Crash Conference,
pp.105-127, 1972.
[30] Bartz,J.A.,"A Three-Dimensional Computer Simulation of a motor Vehicle Crash
Victim, Phase I, Development of the Computer Program," Report CAL No.
VJ-2978-V-1, Calspan Corp., Buffalo, N.Y., July,1971.
[31] Bartz,J.A.,"A Three-Dimensional Computer Simulation of a motor Vehicle
CRash Victim, Phase II, Validation Study of the Model," Report Cal. No.
VJ-2978-V-2, Calspan Corp., Buffalo, N.Y. Dec. 1972.
[32] Fleck,J.T., Bulter,F.E., and Vogel,S.L., "An Improved Three-Dimensional
Computer Simulation of Motor Vehicle Crash Victims," Final Technical Report No.
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AQ-5180-L-1, Calspan Corp., 1974.
[33] Karnes,R.N., "CAL 3D Crash Victim Simulation Computer Program User
Manual," Document No. BCS-G0651, Boeing Computer Service, Inc., Seattle, Wash.,
March 1971.
[34] Fleck,J.T., "Calspan 3-D Crash Victim Simulation Program," Aircraft
Crashworthiness, University Press of Virginia, pp. 299-310, 1975.
[35] Huston,R.L., Hessel,R.E., and Passerello,C.E., "A Three-Dimensional
Vehicle-Man Model for Collision and High Acceleration Studies," Paper No. 740275,
Society of Automotive Engineers, 1974.
[36] Passerello,C.E., Huston,R.L., and Harlow,M.W., "User's manual for UCIN
Vehicle-Occupant Crash Study Model-Version II," University of Cincinnati Report No.
ONR-UC-EA-120174-3, 1974.
[37] Huston,R.L., Hessel,R.E., and Winget,J.M., "Dynamics of a Crash Victim - A
Finite segment Model," AIAA Journal, Vol. 14 No. 2, Feb. 1976, pp. 173-178.
[38] Huston,R.L., Passerello,C.E., Harlow,M.W., and Winget,J.M., "The UCIN 3-D
Aircraft Occupant," Aircraft Crashworthiness, University Press of Virginia, pp.
309-324, 1975.
[39] Huston,R.L., Passerello,C.E., and Harlow,M.W., "UCIN Vehicle-Occupant/Crash
Victim Simulation Model," Structural Mechanics Software Series, University Press of
Virginia, 1977.
[40] Shyh-Chour Huang, “Dynamic Modeling of Human Bodies During Automobile
Collisions,” Dissertation, University of Cincinnati U.S.A.,1990.
[41] Shyh-Chour Huang, and Ronald L. Huston, "A Personal Computer Software for
Dynamic Modeling of Crash", Proceedings of the Eighth International Conference on
Mathematical and Computer Modeling, Maryland, U.S.A., April 1-4,1991;1042-1047.
[42] Shyh-Chour Huang, “Biomechanical Modeling and Simulation of Automobile
Crash Victim“, Vol.57 No.3, Journal of Computers & Structures, 541-549,Nov.,1995.
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