Stress Concentration Factors in Windshields, Windows, and More
Micro-Measurements has a long history of providing accurate strain and stress measurement in a wide range of challenging materials and conditions. Glass, though highly useful in many applications, can shatter due to stress and strain. In the case of car windshields and plate glass windows, glass that fails to withstand stress can be hazardous.
That’s why civil and mechanical engineers trust our bonded foil strain gage sensors to provide clear and accurate measurements on glass.
Application of Strain Gage Sensors to Glass
The application of bonded foil strain gage sensors to glass can be problematic due to the smooth surface and the fact that surface abrasion is generally not allowed on glass or glass-like test articles (due to stress concentrations).
In addition, the poor heat-sink rating of glass can contribute to excessive strain gage failures while soldering, so the use of pre-cabled gages, such as C2A-Series or gage series available with options P or P2, are highly recommended. The primary challenge using strain gage sensors on glass is surface preparation, which must be done carefully so as not to disturb the glass surface and alter strain readings.
One of the oldest American Society for Testing and Materials (ASTM) committees, Committee C14 on Glass and Glass Products, develops test standards for determining the mechanical properties of all types of glasses, including ceramics. ASTM C158 (Standard Test Methods for Strength of Glass by Flexure) provides test methodology for determining the modulus of rupture. The primary challenge using strain gage sensors on glass is surface preparation, which must be done carefully so as not to disturb the glass surface and alter strain readings. When applied properly using these methods, Micro-Measurements strain gages provide highly accurate results.
For more information on strain gage sensors for applications on glass, including glass surface preparation and adhesive / gage application, contact an expert.