A reduced model for the design of glass structures subjected to impact loads

A reduced finite element model for determining the maximum principal stress of a glass pane subjected to dynamic impact load is developed and compared to a full dynamic finite element model. The reduced model is based on the Rayleigh-Ritz method. The Ritz vectors used are determined by simple static load-cases. The model is applicable to centrically and eccentrically applied impact and to glass of various support conditions. It is demonstrated that the model performs well for various types of supported glass panes and impact applied at different locations on the glass pane. The applicability to small or medium sized glass panes is shown through a parametric investigation in which the results are compared to linear and nonlinear finite element solutions. For large glass panes, especially at smaller glass thickness, geometric nonlinear effects must be considered in the analysis. An outline of how to expand the model to include nonlinear geometric effects is given. Finally, it is shown that the reduced model performs excellently in the modeling of a standard laminated glass balustrade with clamp fixings. Apparently, the model is very well suited for strength design of commonly used glass structures.