VEHICLE BUMPER PERFORMANCE STUDY

RESULTS ARE PRESENTED OF A STUDY OF VARIOUS ASPECTS OF VEHICLE BUMPER PERFORMANCE. INCLUDED ARE: CURRENT BUMPER DESIGN, OVERRIDE AND UNDERRIDE PROPENSITY, ABILITY TO SUSTAIN DYNAMIC LOADING, PEDESTRIAN PROTECTION, ANCILLARY USES, AND A SURVEY OF ENERGY-ABSORBING BUMPER CONCEPTS. THE TREND IN CURRENT BUMPER DESIGN IS IMCOMPATIBLE WITH AFFORDING ANY MEASURE OF PROTECTION TO AN IMPACTED PEDESTRIAN. BASIC DESIGN CHANGES ARE PROPOSED TO MINIMIZE LOAD CONCENTRATIONS AND ENTRAPMENT IN THE PEDESTRIAN ACCIDENT. IMPLEMENTATION OF THESE CHANGES SHOULD PROVIDE INCREASED PROTECTION FROM BUMPER HAZARDS IN IMPACTS UP TO 15 MPH. AT THE HIGHER IMPACT SPEEDS (UP TO 40 MPH), BUMPER PROTECTION HAS TO BE CONSIDERED IN TERMS OF A TOTAL PROTECTIVE FRONT-END DESIGN. TWO ANALYTICAL PROCEDURES WERE DEVELOPED; ONE, FOR DETERMINING THE ABILITY OF A BUMPER ASSEMBLY TO SUSTAIN DYNAMIC LOADS, AND THE SECOND, FOR DETERMINING THE DYNAMIC RESPONSE OF A VEHICLE AND ITS OVERRIDE AND UNDERRIDE PROPENSITY IN A BUMPER TO BARRIER IMPACT. THE SAFE TOW LOADS FOR TYPICAL U.S. PASSENGER CARS EQUIPPED WITH ONE TYPE OF COMMERCIAL BUMPER HITCH LA TYPE 3 WHERE ALL LOADING IS CARRIED BY THE BUMPER) RANGE FROM 2,000 TO 3,000 POUNDS DEPENDING UPON THE SPECIFIC CAR MODEL. OF THE ENERGY-ABSORBING CONCEPTS SUITABLE FOR BUMPER APPLICATION, TWO (THE RICH WATER-FILLED AND PONTIAC'S ELASTOMER BUMPERS) HAVE BEEN REDUCED TO PRACTICE. BOTH OF THESE DEVICES BY THE NATURE OF THEIR DESIGN, HAVE RELATIVELY LOW ABSORBING CAPACITY. THE WATER-FILLED BUMPER IS EFFECTIVE IN LOW SPEED IMPACTS (UP TO 20 MPH). THERE IS NO PERFORMANCE DATA ON THE PONTIAC BUMPER. HYDRAULIC CYLINDERS AS ENERGY ABSORBERS HAVE DEMONSTRATED EFFECTIVE- NESS IN REDUCING DECELERATION LEVELS IN FRONT-END BARRIER IMPACTS AT SPEEDS OF 30 MPH. THIS APPROACH HAS POTENTIALLY THE HIGHEST ENERGH-ABSORBING CAPACITY OF ALL OF THE CONCEPTS CONSIDERED. /SRIS/

• Supplemental Notes:
  • 280pp, 80fiG, 25TAB, 28REF
• Corporate Authors:

  American Machine and Foundry Company

  Santa Barbara, CA  United States 
• Authors:
  • Rup, W J
  • Daly, J M
  • Erten, M
• Publication Date: 1968-12

Subject/Index Terms

• TRT Terms: Bumpers; Crash tests; Deceleration; Design; Dynamic loads; Elastomers; Energy absorption; Hydraulics; Motor vehicles; Pedestrian safety; Performance
• Uncontrolled Terms: Cylinders
• Old TRIS Terms: Pedestrian protection
• Subject Areas: Design; Highways; Research; Safety and Human Factors;

Filing Info

• Accession Number: 00223141
• Record Type: Publication
• Source Agency: Nat Safety Council Safety Res Info Serv
• Files: TRIS
• Created Date: Aug 26 1970 12:00AM