Extensive application of advanced composite materials such as Carbon Fibre Reinforced Plastics (CFRP) emerges in design of aerospace structural components. Outstanding weight-related stiffness and strength properties in combination with structural topology solutions may lead to exploitation of full-load bearing potential of composite structures as utilization of the post-buckling region. In order to fully exploit the load-carrying capacity of such structures an accurate and reliable simulation is indispensable. That, however, requires fast tools which are capable of simulating the structural behaviour beyond skin buckling bifurcation points deep into the post-buckling phenomena up to the collapse of structure. In this paper a metamodeling methodology is proposed for post-buckling simulation of cylindrical-stiffened fuselage structures. Proposed methodology for elaboration of the fast simulation procedure for axially loaded stiffened cylinder structures is based on utilization of space-filling design of experiments and parametric and non-parametric approximations. For determination of the most suitable metamodeling technique different methods are compared – second-order global polynomials, second-order Locally-Weighted Polynomials, adaptively constructed sparse polynomials, Radial Basis Functions, Kriging, Multivariate Adaptive Regression Splines, and Support Vector Regression. Continuous design variables (the structural geometrical dimensions) are used together with a discrete variable (number of stiffeners), thus allowing to scale the full-scale structure towards the stiffened panel designs. The proposed and validated simulation procedure is an efficient optimum design tool in elaboration of the trade of design and in assessment of parametrical sensitivity analysis. It enables elaboration of Pareto-optimal fronts which can be used in the optimum design guidelines to realise the full potential of the stiffened composite structures subjected to uniform axial compression.