Advances in Effective Thickness for Laminated Glass Structural Design
Effective thickness is a simplified method for the structural evaluation of laminated glass section properties. The method consists of defining the effective thickness (i.e., the thickness of a monolithic section with equivalent flexural or torsional section properties) between the bounding layered and monolithic limits. The established effective thickness method in the glass design standard ASTM E1300 is limited to a uniformly loaded, simply supported, two-ply beam in flexure, and presents strong limitations for the evaluation of cantilevered glass balustrade flexural performance and structural glass fin stability.
Advancements in effective thickness models have simplified the design of laminated glass. The recently proposed Conjugate Beam Effective Thickness (CBET) method and the Enhanced Effective Thickness (EET) method account for the influence of various boundary and loading conditions and are readily applicable to evaluate the flexure and stability of laminated glass beams with increased accuracy. In this paper, the CBET and EET methods are applied to the structural evaluation of 2-ply cantilevered glass balustrades and multi-ply structural glass fins. Predicted stresses, deflections, and critical buckling loads obtained from simplified methods are compared with finite element analysis model results for illustrative design examples.