Effect of Temperature on Biaxial Strength of Automotive Windshields Corning Incorporated

Format:

Conference/Event

Author/Creator:

Gulati, S. T., author.

Conference Name:

International Body Engineering Conference & Exposition (2000-10-03 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2000

Summary:

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

Notes:

Vendor supplied data

Publisher Number:

2000-01-2722

Access Restriction:

Restricted for use by site license