Application of the Glass Failure Prediction Model to Flat Glass Using Finite-Element Modeling

Architectural glazing designers in the United States and many other parts of the world use prescriptive methods to determine the load resistance (LR) of glazing and glazing constructions in buildings based on a probabilistic theory of glass strength. This theory is known as the glass failure prediction model (GFPM). The GFPM relates the probability of breakage to surface stress magnitude induced by lateral uniform loads acting on the glass as well as the duration of stress. Glass design charts in US model building codes and standards use a nonlinear finite difference model developed during the early 1980s as the basis to determine surface stresses induced by lateral loads. The primary analysis tools available to engineers today are based on the finite-element method and not on the finite difference method. The authors developed a nonlinear finite-element model and applied the GFPM to the nonlinear finite-element model output to determine the probability of breakage for selected glass lite geometry and load combinations. The results of their analyses compare favorably with values in model building codes and standards. This model will facilitate architectural glazing designers when they must design glazing for fenestrations that charts in model building codes and standards currently do not address.