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The purpose of this work is to assess the dynamic mechanical behaviour of a commercial
glass similar to that of the laminated glass structures used for protection and security applications in
buildings. In particular, the study has been focussed on the influence of the strain-rate on the
compressive (standard compression test) and tensile (splitting tensile test) strength of this glass.
Tests at different strain-rates have been performed in the range between 10
-3
to 10
3
s
-1
using
standard test equipment for quasi-static tests and a SHPB equipped with a high-speed camera for the
dynamic ones. Test data for compression tend to show that there is no substantial sensitivity to the
strain-rate concerning ultimate strength and Young modulus. An appreciable increase in the ultimate
tensile strength is revealed at higher strain-rate.
Laminated glass panels are widely used for protection and security applications in buildings.
Their dynamic behaviour, e.g. to blast loading, is influenced by the mechanical properties of the two
materials normally used to build their sandwich structure: the external glass panes and the polymeric
layer (usually PVB Polyvinylbutyral), which binds them together [1, 2]. The technical literature
contains plenty of information about the dynamic mechanical properties of many structural
materials, especially metals, obtained through different test types (such as Split Hopkinson Pressure
Bar techniques, Taylor tests, flyer plate tests, etc.). However, the study of the dynamic mechanical
properties of polymers and glassy materials is not as common. In addition, especially for glassy
materials, many problems occur during dynamic testing due mainly to their brittle behaviour. For
example in these situations it is very difficult for the specimen to reach dynamic equilibrium before
crack propagation and failure, and frequently particular elaboration techniques for the experimental
data must be developed in order to produce meaningful results.
The purpose of this work is to assess the dynamic mechanical behaviour of a commercial glass
similar to that used in laminated glass structures. In particular, the study has been focussed on the
influence of the strain-rate on the compressive/tensile strength of this glass. Cylindrical specimens
have been used both for compression (diameter 5 mm and height 6 mm) and splitting tensile tests
(diameter 9 mm and height 5 mm). With reference to the splitting tensile test (Brazilian test) the
effect of “bearing strips” has also been evaluated in order to better distribute compression loading
and to avoid the propagation of initial cracks. Tests at different strain-rates have been performed in
the range between 10
-3
to 10
3
s
-1
using standard test equipment for quasi-static tests and a SHPB for
the dynamic ones. Strain-rate reported refers to that at maximum stress. For what concerns high
strain-rate tests, wave dispersion phenomena and the effect of local punching at the bar/specimen
interface have been taken into account in order to improve the accuracy. Further, the deformation
and cracking processes of the specimen have been monitored using a high-speed digital camera,
which proves to be crucial in aiding in the interpretation of the data.
Applied Mechanics and Materials Vol. 82 (2011) pp 63-68
Online available since 2011/Jul/27 at www.scientific.net
© (2011) Trans Tech Publications, Switzerland
doi:10.4028/www.scientific.net/AMM.82.63
All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,
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