G. Zucco

Koiter asymptotic analysis of thin-walled cold-formed steel members

Abstract An imperfection sensitivity analysis of cold-formed steel members in compression is presented. The analysis is based on Koiter’s approach and Monte Carlo simulation. If the modes interaction is correctly accounted, than the limit load and the erosion of critical buckling load can be easily evaluated. Thousands of imperfection can be analysed with very low computational cost and an effective statistical evaluation of limit performance can be carried out. The analysis is done on pallet rack uprights in compression, based on an intensive experimental study carried out at the Politehnica University of Timisoara.

Imperfection sensitivity analysis of composite cylindrical shells using Koiter’s method

ABSTRACT The novel methodology for imperfection sensitivity analysis, presented in Barbero et al. [1], is here applied for the evaluation of limit load of composite cylindrical shells. Koiter’s perturbation method is used to calculate the imperfection paths emanating from mode interaction bifurcations, and the Monte Carlo method is used to test a large number of modes and all possible interactions among them. The computational cost is low because of the efficiency of Koiter’s method. The demands of Koiter’s method for accurate evaluations of higher order derivatives of the potential energy are met by a mixed, corotational element.