A THREE-DIMENSIONAL MATHEMATICAL MODEL OF AN AUTOMOBILE PASSENGER

AN ANALYTICAL MODEL HAS BEEN DEVELOPED THAT PREDICTS THE RESPONSE OF AN AUTOMOBILE PASSENGER DURING VEHICLE MOTION OF A GENERAL NATURE, I.E., A THREE-DIMENSIONAL PATH INCLUDING SIMULTANEOUS ROTATIONS ABOUT THE THREE DIRECTIONS.THIS MODEL REDUCES THE PROBLEM OF PREDICTING THE ACCELERATIONS AND FORCES ACTING ON A PASSENGER DURING A COLLISION OR VIOLENT MANEUVER TO THAT OF SPECIFYING THE PATH OF THE VEHICLE AS A FUNCTION OF TIME PLUS THE DEFORMATION PROPERTIES OF THE VEHICLE INTERIOR. THE VEHICLE OCCUPANT IS DEFINED MATHEMATICALLY IN THREE-DIMENSIONS AS AN INDEPENDENT SYSTEM WHICH IS THEN PLACED INSIDE THE VEHICLE BUT NOT CONNECTED TO IT. THE VEHICLE INTERIOR CONTAINS THE PASSENGER WITHIN ITS BOUNDARIES BY APPLYING CONTACT FORCES WHILE THE VEHICLE MOVES THROUGH SPACE. THE VEHICLE INTERIOR IS IDEALIZED WITH 25 PLANAR SURFACES AND INCLUDES LAP AND TORSO RESTRAINT BELTS. THE GEOMETRY OF THE VEHICLE OCCUPANT IS IDEALIZED BY 12 RIGID MASS SEGMENTS INTERCONNECTED IN A PATTERN WHICH REFLECTS THE ARTICULATED NATURE OF THE HUMAN BODY. THIS SYSTEM HAS 31 DEGREES OF FREEDOM WHICH CORRESPOND TO THE SET OF GENERALIZED COORDINATES USED IN LAGRANGE'S EQUATIONS OF MOTION. THESE EQUATIONS ARE SOLVED NUMERICALLY WITH THE AID OF THE IBM 360/65 COMPUTER. "SPINAL ELASTICITY" IS SIMULATED WITH ROTATIONAL SPRINGS IN THE BACK JOINTS OF THE ARTICULATED BODY. AND "MUSCLE TONE" IS SIMULATED WITH ROTATIONAL VISCOUS DAMPERS IN EVERY BODY JOINT. VALIDATION OF THE MODEL HAS BEEN ACHIEVED FOR FRONTAL COLLISIONS. THE MODEL'S PREDICTED RESPONSE OF A DUMMY ON A TEST CART COMPARED WELL WITH ACTUAL TEST DATA. BOTH RESTRAINED AND UNRESTRAINED CONDITIONS WERE ANALYZED. THERE WERE TWO RESTRAINED CONDITIONS: (1) LAP BELT ONLY AND (2) LAP AND TORSO BELT. THE MODEL PROVIDES THE HIGHWAY ENGINEER WITH A TOOL WHICH WILL ENABLE HIM TO APPLY BIOMECHANICS DATA ON HUMAN TOLERANCE LIMITS TO THE PROBLEM OF MODIFYING ROADSIDE STRUCTURES SUCH THAT OCCUPANT INJURIES DURING VEHICLE ACCIDENTS CAN BE REDUCED. /FHWA/

  • Corporate Authors:

    Texas Transportation Institute

    Texas A&M University System, 1600 E Lamar Boulevard
    Arlington, TX  USA  76011

    Texas State Department of Highways & Public Transp

    11th and Brazos Streets
    Austin, TX  USA  78701

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  USA  20590
  • Authors:
    • Young, R D
  • Publication Date: 1970-8

Subject/Index Terms

Filing Info

  • Accession Number: 00222598
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Mar 7 1971 12:00AM