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1
Content available The influence of Material Extrusion process parameters on the porosity and mechanical properties of PLA products for medical applications
Rusińska Małgorzata, Gruber Piotr, Ziółkowski Grzegorz, Łabowska Magdalena, Wilińska Karolina, Szymczyk-Ziółkowska Patrycja
Acta of Bioengineering and Biomechanics
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2023
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Vol. 25, no. 3
EN
The study addresses the growing need for personalized medicine and cost-effective manufacturing by investigating additive manufacturing (AM). It employs the Design of Experiments (DOE) to explore how fused filament fabrication (FFF) parameters affect porosity and mechanical properties of medical-grade polylactide (PLA) samples.
2
Content available remote Damage to inverse hybrid laminate structures: an analysis of shear strength test
Frankiewicz Mariusz, Ziółkowski Grzegorz, Dziedzic Robert, Osiecki Tomasz, Scholz Peter
Materials Science Poland
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2022
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Vol. 40, No. 1
130--144
EN
Hybrid laminates with continuous fiber reinforcement, such as glass reinforced aluminium laminate (GLARE), aramid reinforced aluminum laminate (ARALL), or carbon reinforced aluminum laminate (CARALL), have been developed to increase the lightweight potential and fatigue resistance applied for aircraft structures. However, the use of thermosetting matrices imposes material limitations regarding recycling, malleability, and manufacturing-cycle times. The inverse hybrid laminate approach is based on a continuous fiber-reinforced thermoplastic matrix, in which a metal insert is integrated. For efficient manufacturing of the novel composites in high-volume production processes, conventional sheet metal–forming methods have been applied. It helped to reduce the cycle times and the costs of the forming equipment compared to currently used hybrid laminate-processing technologies. The present study analyzes the damage to the inverse hybrid laminate structures resulting from the interlaminar shear strength test. The tests were performed for eight laminate material configurations, which differed by the type and directions of the reinforced glass and carbon fibers in the polyamide matrix and the number of the fiber-reinforced polymer (FRP) layers in the laminates. Industrial computed tomography and scanning electron microscopy were used for analysis. Observed damages, including fiber–matrix debonding, fiber breakages, matrix fractures, interfacial debonding, and delamination in selected areas of the material, are strictly dependent on the laminate configurations. FRP layers reinforced by fibers perpendicular to the bending axis presented better resistance against fractures of the matrix, but their adhesion to the aluminum inserts was lower than in layers reinforced by fibers parallel to the bending axis.
3
Content available remote Influence of bioactive metal fillers on microstructural homogeneity of PA12 composites produced by polymer Laser Sintering
Gruber Piotr, Ziółkowski Grzegorz, Olejarczyk Michał, Grochowska Emilia, Hoppe Viktoria, Szymczyk-Ziółkowska Patrycja, Kurzynowski Tomasz
Archives of Civil and Mechanical Engineering
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2022
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Vol. 22, no. 3
art. no. e117
EN
In this paper, polyamide 12 (PA12) blends with three types of metallic fillers are tested, which differ in the type of material and its’ morphology. Low content mixtures are taken into consideration (0.5, 1.0, 2.0, 5.0 wt%), since a low impact on mechanical properties along with obtaining antibacterial properties are desired. The investigation focuses on filler distribution as well as the influence on microstructural homogeneity of the base material after processing with polymer Laser Sintering. Moreover, the influence of the filler content on the mechanical properties and fracture behaviour were examined. Processability PA12 with bioactive metal fillers was confirmed, and no significant changes in ductile behaviour of PA12 were observed. An in-depth analysis of the effect of the filler on microstructural homogeneity was conducted.
4
Content available remote Investigation of porosity behavior in SLS polyamide-12 samples using ex-situ X-ray computed tomography
Ziółkowski Grzegorz, Grochowska Emilia, Kęszycki Dawid, Gruber Piotr, Hoppe Viktoria, Szymczyk-Ziółkowska Patrycja, Kurzynowski Tomasz
Materials Science Poland
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2021
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Vol. 39, No. 3
436--445
EN
The paper presents a detailed description of the method of carrying out static tensile tests in ex-situ X-ray computed tomography (XCT) conditions. The study compares samples manufactured with the use of additive technology in two orientations, horizontally and vertically, which correspond to the in-layer and between-layer sintering mechanisms. Both the fracture mechanism and porosity behavior differed significantly for the two manufacturing directions. The conducted analysis made it possible to compare the changes in porosity, the number of pores, and also their diameters and shape before and after the tensile test. This allows for in-depth identification and better understanding of the phenomena occurring during the static tensile test of polyamide-12 samples manufactured using selective laser sintering (SLS) technology.
5
Content available remote New possibilities for in situ CT analysis of additive manufactured samples
Ziółkowski Grzegorz, Treter Grzegorz, Tokarczyk Emilia, Szymczyk-Ziółkowska Patrycja
Technical Transactions
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2020
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Vol. 117, iss. 1
art. no. e2020028
EN
Industrial Computed Tomography (CT) is a broadly used measurement method allowing for quality control of objects produced using additive manufacturing methods. The combination of tensile tests and simultaneous 3D imaging of the behavior of an object under a particular force (i.e. in situ examination – during the process) significantly broadens the possibilities of analyzing objects with a complex internal geometry. The purpose of this paper is to present the author’s project of a mini testing machine, to verify its functioning with regards to a static testing machine, and to present the initial in situ examination results for polymer samples.
PL
Tomografia komputerowa (CT) jest obecnie powszechnie stosowaną metodą pomiarową pozwalającą na kontrolę jakości obiektów wytwarzanych z wykorzystaniem technologii przyrostowych. Połączenie badań wytrzymałościowych z jednoczesnym trójwymiarowym obrazowaniem zachowania się obiektu pod wpływem działania określonej siły (tzw. badania in situ – w procesie) znacznie rozszerza możliwość analizy obiektów o złożonej strukturze przestrzennej. Celem niniejszej pracy jest przedstawienie autorskiego projektu minimaszyny wytrzymałościowej oraz weryfikacja poprawności jej działania w odniesieniu do komercyjnych rozwiązań, a także przedstawienie wstępnych wyników badań in situ dla przestrzennych próbek polimerowych.
6
Content available remote The effect of geometry on mechanical properties of Ti6Al4V ELI scaffolds manufactured using additive manufacturing technology
Szymczyk Patrycja, Hoppe Viktoria, Ziółkowski Grzegorz, Smolnicki Michał, Madeja Marcin
Archives of Civil and Mechanical Engineering
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2020
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Vol. 20, no. 1
144--156
EN
Owing to the possibility of direct processing of CAD models into three-dimensional objects, additive manufacturing (AM) is widely used in the production of individualized bone scaffolds that can lead to perfect restoration of anatomical structures of missing bone tissues. In this work, one of the AM technologies was applied, referred to as Electron Beam Melting (EBM), using Ti6Al4V ELI alloy to produce open-cell structures. Scaffold architecture influences its mechanical properties and is important from the point of view of biological considerations. To optimize mechanical properties, designed geometries were subjected to Finite Element Method analysis and experimental static compression tests. Also, geometric CT analysis of manufactured scaffolds was carried out (geometry deviations up to ± 300 µm). Obtained results have shown that AM can be used to produce Ti6Al4V ELI alloy scaffolds displaying mechanical parameters similar to those of bone tissue (E = 0.45–2.88 MPa). The EBM process affects the microstructure and macrostructural properties of manufactured parts, e.g., through internal porosities present in the material by to unmelted powder particles (internal porosity in range of 1.25–2.25%). To assess the quality and suitability of additively manufactured implants, a multidimensional verification of the impact of the manufacturing process on the properties of the final product was performed.
7
Content available Approach to numerical simulation of an american footbal helmet
Dymek Mateusz, Ziółkowski Grzegorz, Ptak Mariusz
Aktualne Problemy Biomechaniki
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2019
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z. 17
27--34
EN
The article presents the initial analysis of collision of two American football helmets. The aim was to investigate the crashworthiness of the facemask during the collision. In addition, thanks to creating the reference point representing the head inside the helmet it was possible to investigate whether the rotational acceleration occurs. In order to obtain reliable results the Finite Element discrete model was prepared. The study is based on a real helmet model – Riddel Revolution and author’s experience as a player.
PL
Artykuł ma na celu zaprezentowanie wstępnej analizy zderzenia dwóch kasków do futbolu amerykańskiego. Główny nacisk został położony na zbadanie czy kratka kasku nie zostanie uszkodzona przez takowe zderzenie. Dodatkowo został umieszczony punkt masowy, który reprezentuje masę głowy. Dzięki temu jest możliwość zbadania przyspieszeń rotacyjnych działających na mózg zawodnika. W tym celu został stworzony model dyskretny (obliczeniowy) kasku. Badanie jest przeprowadzone z użyciem prawdziwego kasku – Riddel Revolution oraz przy użyciu doświadczenia jednego z autorów.
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