ENERGY-ABSORBING BARRIER BEAMS SUSPENDED FROM LINEAR SUPPORTS (ABRIDGMENT)

THE POSSIBILITIES OF IMPROFING TOTAL GUARDRAIL SYSTEM PERFORMANCE BY FURTHER EXPLOITATION OF BEAM PROPERTIES WAS RESEARCHED. A MORE GRADUAL APPLICATION OF DECELERATION FROCES AND THE EFFICIENT USE OF BEAM WERE INVESTIGATED. THE FORMER IS ACCOMPLISHED BY HYPOTHESIZING A STANDOFF SUSPENSION SEPARATING BEAM FROM POST. RESEARCH EFFORT HAS BEEN DIRECTED TOWARD DEVICES THAT OFFER PROMISE AS ENERGY-ABSORBING STANDOFF SUSPENDIONS FOR GUARDRAIL BEAMS. IT WILL HAVE AN OVERALL LINEAR LOAD-DEFLECTION RELATION RATHER THAN THE USUAL RIGID-PLASTIC ONE ASSOCIATED WITH POSTS HAVING NO SUSPENSION. AN EFFICIENT BEAM WILL UTILIZE ELASTIC-PLASTIC FLEXURE TO ABSORB ENERGY AND STIFFNESS TO SPREAD THE WORK OUT OVER THE SUPPORT SYSTEM. THE APPROPRIATE SIZE FOR THE MOST COST EFFECTIVE CONFIGURATION DEPENDS ON PERFORMANCE REQUIREMENTS AND COMPONENT COSTS THAT ARE INCORPORATED IN A MATHEMATICAL MODEL. DETAILS ARE GIVEN OF A SYNTHETIC MODEL WHICH IDENTICALLY AND SIMULTANEOUSLY SATISFIES THE REQUIREMENT THAT ENERGY ABSORBED IS THE AMOUNT THAT IS NECESSARY TO EFFECT VEHICLE REDIRECTION, AND THE REQUIREMENT THAT THE MAXIMUM LATERAL DECELERATION LEVEL IS 5 G. THE MODEL GIVES THE BEAM SIZE AND SUSPENSION REQUIREMENTS. BEAM DEFLECTIONS ARE MINIMALLY CONSISTENT WITH THE PRECEDING PERFORMANCE REQUIREMENTS. INPUT DATA RELATING TO IMPACT CONDITIONS, MATERIAL OR COMPONENT CAPACITIES, AND COMPONENT COSTS ARE OUTLINED. THE TEST RESULTS OBTAINED ARE TABULATED, COMPARED AND DISCUSSED. BASED ON THE STUDY, THE OBSERVATION IS MADE THAT HIGHER PERFORMANCE REQUIREMENTS FOR INCREASED SPEED WITH REDUCED DECELERATION LEVELS WILL NECESSITATE BARRIER SYSTEMS CAPABLE OF LARGE BEAM DEFLECTIONS. BEAM INTERACTIONS WITH OTHER TYPES OF SUSPENSION POST MODELS SHOULD BE INVESTIGATED WHERE THE BEAM DIMENSIONS ARE ADJUSTED SO THAT ALL VARIANTS SATISFY THE SAME PERFORMANCE REQUIREMENTS.

Media Info

  • Media Type: Print
  • Features: References; Tables;
  • Pagination: pp 82-84
  • Monograph Title: Traffic safety barriers and lighting supports
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00210044
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jul 31 1974 12:00AM