Laser-written optical sensors in pre-stressed architectural glazing

01 January 2021 → 31 December 2024
Research Foundation - Flanders (FWO)
Research disciplines
  • Engineering and technology
    • Construction materials technology
    • Structural engineering
    • Photonics, light and lighting
    • Smart sensors
glass sensors laser architectural glazing
Project description

Detailed knowledge of the stress history by structural health monitoring (SHM) would allow more accurate lifetime prediction of architectural and structural glass. In contrast to alternative SHM methods, laser-written optical sensors in the bulk are very attractive as they do not significantly interfere with demanding optical requirements of such glazing. Consequently, overall objective of the proposed research is to realize Bragg grating sensors directly and invisibly in the bulk of structural glass using ultra-fast direct laser writing and at the same time solving the strain-temperature cross-sensitivity. Equally important is to study the effects of lasing on the glass strength and residual stress distribution. Focus will be on two glass types: “thick” thermally toughened soda lime silica glass, commonly used in architectural applications, and ultra-thin alumino silica glass, which is emerging in the field. Research will concentrate on i) laser-writing low loss optical waveguides in pre-stressed glass, ii) studying the influence those waveguides have on the strength of glass and its residual stress distribution by means of both nondestructive and destructive tests, iii) realizing and thermo-mechanically characterizing Bragg grating sensors which can discriminate between strain and temperature acting simultaneously on the glass. Finally, for both glass types proof of concept demonstrators will be made and tested.