Podrobno

In the area of glazing façades and windows, the increasing environmental demands have boosted the development of insulating-glass units (IGUs). There is already 4–6 pane glazing on the market, with heat transmittance U$_{cw}$ < 0.40 W/m$^2$K, which offers exceptional energy efficiency and living comfort. There is still a lack of standardized engineering methods for their design, however. The lateral load resistance of glass panes in insulating glass units is addressed in the standards EN 16612 and ASTM E1300-12a, but in both, the calculation methods employed are simplified by way of the linearization of the gas law and are applicable only to double and triple glass units. In this paper, we present a recursive method that accurately satisfies the conditions of static equilibrium and the gas law. The methodology preserves the rationale of EN 16612, in which the problem is split in two components: single glass pane bending and load sharing in IGUs, with the results of the former serving as input to the latter. The proposed methodology is based on the Taylor expansion of the gas law and equilibrium equations, which, in contrast to the standard method, completely eliminates the linearization error through a recursive process. Verification cases show that the error due to linearization can reach up to 30 %, a deficiency that the proposed method eliminates. Unlike the methods in the standards, ours provides a general solution for IGUs consisting of an arbitrary number of glass panes. Despite this general applicability, it preserves computational efficiency, simplicity, and suitability for basic engineering design. Beyond improving the existing calculations for double and triple glass units, the proposed method also represents a simple, stable and robust calculation approach for multi-pane IGUs, e.g. quadruple glass units, which are already on the market, as shown by real case studies. For practical purposes, a condensed presentation of the calculation process for these IGUs is given in the Appendix.