Quasi-static compressive testing up to densification of some selected auxetic structures in two different directions was performed to determine complete deformation behaviour of these structures. Furthermore, the high strain rate experimental testing of selected auxetic cellular structures was performed to determine also the deformation behaviour at higher strain rates. Subsequently, representative discrete computational models built with the beam finite elements were developed and validated by experimental data. The values of the critical strain rate determined by analytical expressions and visual observation of deformation procedure in experiments were also compared. Validated discrete computational models were used for further optimisation of auxetic structure geometry to obtain user defined response during loding of graded structures.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 20847126The presentation will give a short overview of cellular materials in general. Initially, their properties, fabrication procedures and application possibilities will be discussed. Then their geometrical characterization, experimental testing and computational modelling within the finite element method of various cellular metal types will be described. The geometrical characterisation is based on the analysis of micro computed tomography scans and proper recognition of their internal cellular structure, taking into account the statistical distribution of morphological and topological properties. The results of conducted geometrical analysis provided means to develop methodology for proper 2D and 3D geometrical modelling of irregular cellular materials and consequent formation of computational models. The numerical models were validated by quasi-static and dynamic mechanical experimental tests supported by infrared thermography.
B.04 Guest lecture
COBISS.SI-ID: 20960278The international conference focused on lightweight multifunctional stochastic and periodic cell materials (e.g. metal foams, auxetic structures, periodic and optimized honeycomb load-bearing structures) with properties that make them attractive for many applications, including but not limited to energy absorption (protection in impact), lightweight structural sandwich panels (as core), vibration damping devices and thermal and sound insulation.
B.01 Organiser of a scientific meeting
COBISS.SI-ID: 22615062The obtained Slovenian patent describes an axisymmetric chiral cellular structure, which consists of the same or/and variable chiral unit cells. Under loading it deforms in the way to exhibit a negative Poisson ratio (auxeticity) in all coordinate directions. By changing the parameters of the unit cells of the axisymmetric structure, a spatially variable structure with variable properties can be created. At uniaxial loads, the structure deforms isotropically in the radial direction. A European patent is also in the application phase.
F.33 Slovenian patent
Prof. Vesenjak je bil povabljen kot gostujoči urednik mednarodne znanstvene revije Metals (razvrstitev revije: prva četrtina A1), kjer je urejal in recenziral originalne znanstvene prispevke za posebno izdajo: Cellular Metals: Fabrication, Properties and Applications (Celične kovine: izdelava, lastnosti in uporaba).
C.03 Guest-associated editor
COBISS.SI-ID: 15976214