Effect of temperature on biaxial strength of automotive windshields

S. T. Gulati, J. D. Helfinstine, T. A. Roe, M. A. Khaleel, R. W. Davies, K. K. Koram, V. Henry

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

This paper focuses on the effect of temperature on biaxial strength of curved, symmetrically laminated, automotive windshields. In view of their aspheric curvature, the measurement of biaxial strength requires a special ring-on-ring test fixture with compliant loading and support rings. The key factors that affect strength are (i) fatigue behavior of surface flaws, (ii) expansion mismatch between glass and PVB interlayer, and (iii) interfacial bond integrity. These, in turn, depend on the operating temperature which for automotive windshields can range from -40°C in winter to +50°C in summer. The data show that the biaxial strength is 21% higher at -40°C and 28% lower at +50°C than that at room temperature. An assessment of fatigue and interfacial bond integrity shows that strength changes of these magnitudes are predominantly caused by residual stresses arising from expansion mismatch between glass and PVB interlayer. The fracture pattern indicates that the bond integrity is excellent over the range of test temperatures. The fatigue resistance of surface flaws, which depends on both the glass composition and molecular activity of water vapor, is considerably lower at +50°C than -40°C and could well account for the high variability in strength data. Such a variability in measured strength can have an adverse effect on the long-term mechanical reliability of windshield. The implication of altered mechanical reliability on occupants' safety is discussed briefly.

Original languageEnglish
Title of host publicationSAE Technical Papers
DOIs
Publication statusPublished - 1 Dec 2000
Externally publishedYes
EventInternational Body Engineering Conference - Detroit, MI, United States
Duration: 3 Oct 20005 Oct 2000

Other

OtherInternational Body Engineering Conference
CountryUnited States
CityDetroit, MI
Period3/10/005/10/00

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ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering

Cite this

Gulati, S. T., Helfinstine, J. D., Roe, T. A., Khaleel, M. A., Davies, R. W., Koram, K. K., & Henry, V. (2000). Effect of temperature on biaxial strength of automotive windshields. In SAE Technical Papers https://doi.org/10.4271/2000-01-2722