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Opis: Background/Objectives: Developing functional tissue constructs via 3D bioprinting relies heavily on scaffold architecture, demanding precise mechanical tunability and highresolution feature fidelity. Methods: This paper presents a novel approach utilising photocurable resins and resin 3D printing to fabricate auxetic axisymmetric chiral structures (ACSs), which can be used for advanced scaffold engineering. Results: The experimental tests showed that the optimised ACS (optACS) possess superior mechanical properties compared to their non-optimised counterpart. Both analysed structures possess an auxetic behaviour up to 40% longitudinal strain, with a Poisson’s ratio of about −0.1. Conclusions: This auxetic capability is promising for biomedical applications, particularly in developing enhanced stents or tissue scaffolds.
Ključne besede: auxetic, axisymmetric chiral structures, 3D printing, mechanical testing, deformation behaviour, optimisation
Objavljeno v DKUM: 10.12.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (1,77 MB)
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Opis: A review of the fatigue behavior of triply periodic minimal surface (TPMS) metamaterials with consideration for their fabrication is presented in this paper. The review analyses the most common TPMS geometries used due to their mechanical characteristics. Production methods and the base materials used are presented with the key advantages and drawbacks. Furthermore, the mechanical characteristics of cellular structures with emphasis on TPMS geometries are described. Lastly, the state-of-the-art findings of their fatigue behavior are analyzed and explained. Based on the findings in this article, cellular geometries based on TPMS are superior to conventional cellular structures when comparing their fatigue life. Because of the smooth transitions between struts or surfaces, the stress distribution is much more uniform without stress concentration zones.
Ključne besede: cellular structures, TPMS metamaterials, production technologies, mechanical characterization, fatigue behavior
Objavljeno v DKUM: 09.12.2025; Ogledov: 0; Prenosov: 2
Celotno besedilo (2,92 MB)
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Opis: V sklopu diplomske naloge je bila v podjetju VIRS d. o. o. analizirana obstoječa konstrukcija nosilca senzorskega sistema FUJI-CAM 2.0 pri robotskem varjenju, ki je zahtevna in draga za izdelavo, njena montaža pa je kompleksna zaradi več sestavnih delov. Cilj naloge je bil razviti lažjo in enostavnejšo konstrukcijo, primerno za izdelavo s 3D-tiskom. Po začetni analizi so sledili 3D-modeliranje nove konstrukcije, optimizacija, numerična simulacija in primerjalna analiza med obstoječo in novo konstrukcijo. Rezultati primerjalne analize so potrdili ključne prednosti novo razvite konstrukcije, ki omogoča potencialno uporabo v realnem industrijskem okolju.
Ključne besede: robotsko varjenje, FUJI-CAM 2.0, 3D modeliranje, Autodesk Inventor, 3D-tisk
Objavljeno v DKUM: 25.09.2025; Ogledov: 0; Prenosov: 19
Celotno besedilo (2,93 MB)

Opis: Auxetic materials and structures have a negative Poisson’s ratio (PR), which means that they expand under a longitudinal tensile loading and shrink under compressive load. This property gives them an increased shear resistance, damping and energy absorption capabilities. Chiral geometries are among the most effective auxetic structures for their ability to convert the axial loading in the rotation of their internal nodes. In the present work, a novel 3D chiral geometry is presented, and its response is investigated both experimentally and numerically. It is made of spheres placed following a Body Centered Cubic lattice; each one connected to the closest neighbors by eight ligaments. A sample was 3D-printed and mechanically tested in compression exhibiting an auxetic behavior in certain directions. A Finite Element model was then developed, successfully reproducing the outcome of the experimental tests, both in terms of force and PR. Then, a numerical testing campaign was performed on representative units constrained using periodic boundary conditions. This campaign allows to evaluate the mechanical properties of the structure as a function of its geometrical parameters. It shows to be able to exhibit an approach a PR of −1 in all the directions. Moreover, the relationship between the sphere’s rotation, PR and instability was investigated.
Ključne besede: three-dimensional auxetics, chiral, negative Poisson’s ratio, instability
Objavljeno v DKUM: 28.08.2025; Ogledov: 0; Prenosov: 4
Celotno besedilo (6,04 MB)
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Opis: V diplomskem delu je obravnavan manipulator aluminijastih bram, ki se uporablja za transport in manipuliranje težkih aluminijastih bram v industriji. Z uporabo programa PrePoMax je bila izvedena numerična analiza vilic manipulatorja, s katero smo preučili mehansko obnašanje posameznih komponent. Pri diskretizaciji geometrijskega modela je bila uporabljena metoda končnih elementov, za izbor ustrezne mreže pa je bila izvedena konvergenčna analiza. Dobljeni rezultati so ustrezno analizirani ter nudijo vpogled v trdnostne lastnosti komponent ter možne izboljšave njihove zasnove.
Ključne besede: Manipulator, trdnostna analiza, metoda končnih elementov, konvergenčna analiza
Objavljeno v DKUM: 08.07.2025; Ogledov: 0; Prenosov: 99
Celotno besedilo (3,23 MB)