Next Generation Simplified Relationship for Structural Silicone Joint Dimensioning

Bonding of glass onto aluminum frames, known as Structural_Silicone_Glazing (SSG), has been applied for more than 40years on facades. Traditionally silicone bite is calculated using a simplified equation assuming a homogenous stress distribution along the sealant bite. Finite element analysis (FEA) allows to describe the accurate local stress distribution within sealant volume. Due to design complexity of façades the requirements to use FEA increased recently. However, there is no standardize methodology to run FEA for evaluation of SSG as well as complexity of FEA is limiting factor to run the calculation on most of projects.

For these reason, a simplified analytical method was developed which predicts deformation of SSG extremely well compared to FEA predictions. The basis of the method was develop 25years ago and is included as annex in ETAG002. The method is based on the assumption that sealant does not influence the bending of glass, which can be calculated using the assumption of simply supported boundaries. The validation of the method was done by comparison of physical measurements, results from FEA and the simplified calculation method. To increase the accuracy further, an extension of the simplified relationship for nonlinear material is proposed, assuming a NeoHookean stress_strain behavior.