A hybrid subspace analysis procedure for non-linear postbuckling calculation

A finite element based hybrid subspace analysis procedure to predict the non-linear behaviour of statically loaded structures is presented. The basic idea is to reduce the total number of degrees of freedom significantly, utilizing global shape functions like buckling modes and path derivatives in a so-called Rayleigh–Ritz approach. The transformation from the full into the reduced system and vice versa as well as the calculation of the global shape functions is detailed. The presented flow-chart of the computational procedure has been implemented in a finite element environment. Numerical examples provide an insight into the potential of the approach to solve accurately and efficiently non-linear problems within the design phase.