Validity of the Shear Panel Theory as a Reduced Modelling Approach

The increasing complexity of large-scale thin-walled structures can be handled by using a hierarchical modelling approach. However, in structural engineering a true preliminary design phase is frequently skipped, since reduced models are often either unavailable or unsuitable for the necessary degree of complexity. Before FEM became established, the shear panel theory was used to calculate thin-walled structures efficiently. While numerical finite element formulations of the shear panel theory have been compared to analytical solutions only, there has been limited review of the validity of the underlying assumptions and accuracy of the analytical model itself. The question arises of whether the shear panel theory provides a suitable reduced modelling approach. The aim of this work is to investigate the limitations of the shear panel theory within the preliminary design of thin-walled structures. An extensive parameter study using a detailed FEM model of a plane shear panel was conducted to compare the calculated stiffness and stress state with those of the analytical model. The models show different behaviour in stiffness and stress state for non-rectangular panels. This indicates that the assumptions of the shear panel theory violate the compatibility conditions between the shear panel and the surrounding stiffeners for non-rectangular panels.