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An innovative type of connections for glass components, called laminated connections, has been developed in the last years. Two materials have been used for laminated connections: the transparent ionomer SentryGlas (SG) from Kuraray (former Dupont) and the Transparent Structural Silicon Adhesive (TSSA) from Dow Corning. In this paper, the mechanical behaviour of SG and TSSA bulk materials is studied under uniaxial tensile stress condition. The effects of strain rate and temperature variations are investigated. Particular attention is paid (i) to the study of these polymers in cured condition and (ii) to the computation of true stress and strain field during the tests. Firstly, it is observed that the mechanical behaviour of both SG and TSSA are temperature and strain rate dependent. These effects are quantitatively determined in the paper. Secondly, two additional phenomena are observed. For TSSA, it is observed that the material goes from fully transparent to white colour, exhibiting the so-called whitening phenomenon. For SG, instead, it is observed that the strain field distribution is dependent on the temperature. More specifically, the material exhibits a non-uniform strain field distribution due to the occurring of the necking phenomenon. Measurements along the specimens, using Digital Image Correlation techniques, showed that the localized strain propagates over the full specimen length, resulting in a cold-drawing phenomenon. Finally, it is also shown that engineering and true stress-strain definition exhibits large deviation indicating that the finite deformation theory should be used for the computation of the stress-strain curves to be implemented in numerical modelling.

Connections between structural glass components represent one of the main critical aspects of glass engineering. In the last years, a novel typology of adhesive connections has emerged, known as laminated adhesive connections. Two adhesive materials for laminated connections in glass applications are used in this work: the transparent ionomer SentryGlas® (SG) from Kuraray and the Transparent Structural Silicon Adhesive (TSSA) from Dow Corning. Both SG and TSSA show a complex behaviour dependent on strain rate and temperature. This work presents a study that aims (i) to investigate the mechanical behaviour and strength of this connection typology under shear loading and (ii) to quantify the effects of strain rate and temperature on the strength of the connections. This is done by means of a combined experimental, analytical and numerical study on laminated connections made of circular metal connectors bonded to rectangular glass plates. The experimental investigations presented in this work showed that temperature and strain rate variations have important effects on the mechanical response of the connections. Three-dimensional numerical analyses showed a non-uniform stress field with large gradient over the three dimensions. Through analytical studies, prediction models are finally proposed for the shear resistance of TSSA and SG laminated connections. The models are obtained developing an algorithm for multi-dimensional non-linear models with variable standard deviations. A logarithmic law is proposed for the strain rate effects for both TSSA and SG connections. Linear and inverse hyperbolic-tangent-based laws are instead proposed for the TSSA and SG temperature behaviour respectively.

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