Feasibility of Measuring Stress in Glass with a SCALP

Overview

Authors

Photo of Nabhajit Goswami

Nabhajit Goswami

Student

Michigan Tech University

ngoswami@mtu.edu

Photo of Stephen M Morse, P.E., Ph.D.

Stephen M Morse, P.E., Ph.D.

Assistant Professor, Civil and Environmental Engineering Assistant Professor, Mechanical Engineering-Engineering Mechanics

Michigan Tech University

smmorse@mtu.edu


Keywords


Abstract

The SCALP device is designed to measure the residual compressive surface stress of glass. As the SCALP does not rely on the birefringence properties of the Tin present on the glass surface the device should be able to measure the stress in a glass sample regardless of whether it is due to the residual compressive surface stress or mechanically imposed due to an applied load. The feasibility and accuracy of using a SCALP to measure imposed stress due to an applied load are explored for heat-treated and annealed glass. Multiple specimen sizes and heat-treatment are used in a 4-point bending test with varying applied loads. The ability to quickly and easily measure the stress in a glass component provides valuable insight into the loading (state of stress) before and after installation and while the component is under load.

Introduction

Glass is a construction material that is constantly evolving with the passage of time. With new architectures, the shape and use of glass from rectangular window pane have evolved to

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Background

Optical anisotropic materials which can resolve light into two orthogonal components and transmit the components with different velocities are known as birefringent or birefractive or doubly refracting materials. Since the

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Test method for determining the feasibility of measuring stress in glass

A 4-point bending rig was built for this experiment and the stresses measured with the SCALP and the GASP were compared to the stress calculated analytically at the extreme most

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Results and Discussion

Tables 1 through table 3 are the SCALP reading of the fully tempered glass with the difference in stress between analytical and measured and the percentage difference tabulated. The SCALP

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Conclusion

This paper looked into the method to measure the installation stresses using instruments used in the glass industry – the SCALP and the GASP. The experiments were repeated to see

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Rights and Permissions

  • Aben, H., Anton, J., Errapart, A., Hödemann, S., Kikas, J., Klaassen, H., & Lamp, M. (2010). On non-destructive residual stress measurement in glass panels. Estonian journal of engineering, 16(2), 150.
  • Äppelqvist, M. (2015). Curved glass: an obstacle or opportunity in glass architecture.
  • Belis, J., Inghelbrecht, B., Van Impe, R., & Callewaert, D. (2007). Cold bending of laminated glass panels. Heron, 52(1-2), 123-146.
  • Trate, D. J., Griffin, J. A., & Zickel, M. (1999). Windshield Investigation-Manufacturing & Installation Stresses (No. 1999-01-3160). SAE Technical Paper.