Mariusz Urbaniak

Influence of Boundary Conditions on the Critical and Failure Load in the GFPR Channel Cross-Section Columns Subjected to Compression

Thin-walled structures are widely used in building structures such as thin-walled vessels or storage tower, beam-columns of houses and halls, as components for cars, boats or airplanes and in sport industry. These types of structures are made not only as steel, but nowadays of composite materials.This paper deals with buckling and postbuckling behaviour and presents the experimental results for thin-walled composite columns with channel cross-section subjected to compression.

Orthotropic Parameters of PU Foam Used in Sandwich Panels

Polyurethane foam used as a core material in sandwich panels is considered in the paper. In this class of structures foam-filled material is treated as an isotropic, elastic material very often. Then, only two independent material parameters are needed to describe this material. Usually, they are chosen from the Young’s modulus E, the shear modulus G or the Poisson’s ratio \(\nu \). In fact, when the material under consideration is a porous structure like a polyurethane foam, the identification of the mechanical properties of this material (even for the isotropic model) is an intricate task. Additionally, as will be shown in the paper, the foam stress-strain response is a function of the applied load. Therefore, the orthotropic behavior of the PU foam is analyzed. To determine mechanical parameters standard tests and a Digital Image Correlation (DIC) technique (named Aramis) are applied. The experimental results are discussed in detail.