ASTM International published a new glass design standard, ASTM E3491, “Standard Practice for Determination of Laminated Glass Effective Thickness.” The new standard practice is for determining laminated glass effective thickness, including calculation methods for various configurations of glass plies bonded with polymeric interlayers.
According to ASTM officials, existing standards, such as ASTM E1300, have not improved the evaluation of cantilevered laminated glass or included a set of solutions for common laminated glass design conditions. Laura Galuppi, associate professor of structural mechanics at the University of Parma, Italy, in collaboration with Adam Nizich, senior associate at Front Inc., notes that the current approach in ASTM E1300 was inaccurate for cantilevered laminated glass balustrade design and developed the Conjugate Beam Effective Thickness (CBET) method for the evaluation of two-ply cantilevered laminated glass.
In response, the ASTM subcommittee E06.52, led by task group leader Nizich, developed ASTM E3491, which incorporates the CBET method and establishes effective thickness solutions for evaluation of stress, deflection and stability of two-, three- and multi-ply laminated glass beams, plates and structural glass fins for 14 loading and boundary conditions.
Officials say that by offering analytical guidance beyond the conditions previously addressed in ASTM E1300 and Eurocode 10, ASTM E3491 has the potential to improve efficiency and consensus for structural glass analysis. As part of the E06.52 effort to develop a contemporary set of glass design standards, the subcommittee is evaluating further revisions to ASTM E1300 to adopt ASTM E3491 and further publication of new structural glass design standards.
Correction: Adam Nizich was the Task Group Leader for the ASTM Subcommittee E06.52