Experimental and numerical characterization of twisting response of thin glass

Laura Galuppi,Enrica Riva

doi:10.1007/s40940-022-00166-0

Abstract

The use of new generation thin, lightweight and damage-resistant glass, originally conceived for electronic displays, is moving its first steps in the built environment, in particular for adaptive and movable skins and façades. Its experimental characterization represents pearhaps one of the main open problems in glass research and engineering. Indeed, standard methods to test the glass strength cannot be used, due to geometrical nonlinearities, thwarting the correct procedure and the strenght calculation. Here, an innovative test procedure is proposed, where a rectangular thin glass element is twisted with high distortion level, while rigid elements constrain two opposite plate edges to remain straight. A dedicated experimental apparatus, that can be used to test specimens with different size and thickness, has been designed and used to test, up to rupture, chemically tempered thin glass with thickness of 1.1 mm and 2.1 mm. Experimental results have been compared to those of numerical analyses, with particular regard to the influence of different constrain conditions on the plate response.

Highlights

The external skin of a building delimits the indoor space, controls the energy transfer between inside and outside and defines the aesthetics of the building
The twisting angle have been measured with the angular position transducer mounted on the shaft of the gear motor, while the torque has been measured with a torque meter
An innovative test procedure is proposed to evaluate the response of thin glass undergoing large displacement twisting

Summary

Introduction

The external skin of a building delimits the indoor space, controls the energy transfer between inside and outside and defines the aesthetics of the building. It is suitable to be used in kinematic or adaptive designs (Topçu 2017; Silveira et al 2018; Bedon et al 2018), where its high flexibility allows for changes in orientation and position by bending the elements, avoiding the use of hinges in systems of foldable rigid panels. This has suggested its use for structures suitable for strong modification of shape and openings, as stadium roofs, lightweight retractable canopies (Neugebauer 2015) and movable greenhouses (Galuppi 2018; D’Ambrosio and Galuppi 2019)

Methods

Results

Conclusion