Post-buckling analysis of composite stiffened panels: A systematic analysis on the influence of imperfections

Pushing the envelope of aerospace structures requires the complete exploitation of their potential in terms of load-carrying capacity per unit weight for both economic and ecological reasons: the two most important being the reduction of fuel consumption and greenhouse gas emissions. A key approach involves allowing structures like stiffened...

An Efficient 3D-model for the Micro-Scale Analysis of Geometrically Imperfect Fibre-Reinforced Composites

This work develops a stand-alone Finite Element-based Unit Cell for the modelling of Fibre Reinforced Composites, capable of capturing 3D stress states and geometrical imperfections at the micro-scale. The project considers different beam and 3D elements for this purpose and draws comparisons between them based on computational efficiency,...

Measuring geometric imperfections of variable–angle filament–wound cylinders with a simple digital image correlation setup

Measuring the geometric imperfections in cylindrical shells is a critical step necessary to create accurate numerical models that can capture the imperfection-sensitive behavior of these structures. Modern composite structures, such as variable–angle filament–wound (VAFW) cylinders, have a unique imperfection signature that is still unknown to...

Buckling and free vibration study of variable and constant-stiffness cylindrical shells

The ability to steer carbon fibre tapes, varying the tow angle, can widen the designs possibilities of cylindrical shells that are one of the main components of aerospace structures. This research presents experimental and numerical investigation of two carbon fibre reinforced plastic cylindrical shells – a cylinder with conventional layup made...

Resistance of cold-formed high strength steel angles

This paper describes a study of the behaviour of cold-formed high strength steel angles. Thirty-six specimens with different cold-formed angles (90°, 100°, 120°, 140°, 160°, and 170°) and different thicknesses (4 mm and 6 mm) were considered. The initial geometric imperfections of the specimens were determined using the 3D laser scanning...

Computational module for the buckling and post-buckling behavior of a cylindrical shell with a two-mode imperfection