On a High-Fidelity Hierarchical Approach to Buckling Load Calculations

A step towards developing a new design philosophy for buckling-critical thinwalled shells is described. This new design philosophy is intended to advance thinwalled shell design technology from the traditional empirical design approach used today towards a science-based design-technology approach. This science-based design-technology approach is based on the hierarchical “high-fidelity-analysis” approach to buckling load calculations proposed by Arbocz et al. [1] where the uncertainties involved in a design are simulated by refined and accurate numerical methods. This hierarchical analysis approach includes three levels of shell buckling analyses that range from classical linear bifurcation buckling analysis (Level-1 analysis) to nonlinear finite element collapse analysis (Level-3 analysis) to provide an accurate prediction of the critical buckling load of a given shell structure. The critical buckling load and the estimated imperfection sensitivity of the shell are verified using a sufficiently refined finite element model with current generation two-dimensional shell analysis codes that include both geometric and material nonlinearities. The new approach is demonstrated for a quasi-isotropic composite shell [2].