SAFETY CHARACTERISTICS OF COMPOSITE GLASS SCREENS UNDER CHANGING GLASS TEMPERATURES

SICHERHEITSEIGENSCHAFTEN VON VERBUNDGLASSCHEIBEN BEI WECHSELNDEN SCHEIBENTEMPERATUREN

Tests were carried out at the Institute for Vehicles, Technical University of Berlin, to establish the temperature-dependence of the most important factors influencing the safety properties of bonded glass screens having variable layer thickness. The author reports on the establishment of the parameters to be examined, the structure and execution of the tests, the results and the views derived on ways of improving this occupant restraint system. The safety properties of bonded windscreens depend very much on the temperature of the screen because of the thermoplastic properties of the bond material (polyvinylbutyral). This temperature determines both the strength and the plastic ductility. A compromise has to be found between the conflicting requirements of greater impact strength and greater plastic ductility. As the severity index values of 0.76 mm-hpr-layer, which are in themselves favourable, are offset by an inadequate resistance to penetration and the associated risk of injury caused by cuts, and as on the other hand a thicker layer results in unbearably high decelerations of the head, conventional composite windscreens cannot be improved solely by making the layer thicker. As an improvement the author recommends A different screen structure and /or different tensioning which, starting from a defined impact speed, would give the head a longer path in which to stop, thus avoiding penetration, and minimizing the risk of injuries to the skull in those cases where there is less deceleration of the head. /TRRL/

  • Corporate Authors:

    Franckhlsche Verlagshandlung

    Pfizerstrasse 5, Postfach 640
    7000 Stuttgart 1,   Germany 
  • Authors:
    • Kramer, M
  • Publication Date: 1972-10

Language

  • German

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00096904
  • Record Type: Publication
  • Source Agency: Federal Institute of Road Research, Germany
  • Files: ITRD, TRIS
  • Created Date: Sep 10 1975 12:00AM