Material Properties of a Structural Silicone for Linear Adhesive Glass-Metal Connections

Abstract

During recent years, adhesives are more frequently used for glass applications in buildings, and according knowledge on adhesive glass-metal connections increased exponentially. However, further research regarding the performance of such connections remains indispensable to further optimise existing concepts or to develop and implement new technologies. To analyse the mechanical behaviour of adhesive glass-metal connections, computer simulations based on the finite element method can be performed. To do so, material properties of all components have to be introduced in the form of stress-strain curves, which can be obtained through experimental tests on adhesive bulk material. Here, the focus is on adhesives suitable to transfer significant loads between a structural glass panel and a thin-walled steel frame. In this contribution, the material properties of a structural silicone, Sikasil^® SG-500, were determined through several experiments. Tensile tests on dumbbells, compression tests on cylindrical samples and thick adherends shear tests (TAST) were performed according to the available standards. Different displacement rates were considered to study the visco-hyperelastic behaviour of the structural silicone. Subsequently, possible theoretical material laws were assessed for their ability to approximate the experimental obtained stress-strain relationships. This paper describes the test procedures, reports about the fabrication process of the test samples, presents the obtained experimental data and proposes possible material laws for the silicone. From the tests, no significant differences in tensile strength and shear strength were obtained for the displacement rates used in this research. However, the stiffness in tension, compression and shear did depend on the test speed.