Wyniki wyszukiwania - BazTech

1

Ocena możliwości zastosowania powłoki laminatowej do naprawy i wzmocnienia płaszcza stalowego zbiornika paliwowego o osi pionowej

Gacki Dawid, Słowiński Kamil

Materiały Budowlane

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2024

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nr 5

31--35

PL

W artykule przedstawiono przebieg i rezultaty badań, których celem była ocena wybranych właściwości powłok poliestrowo-szklanych stosowanych do naprawy i wzmacniania płaszczy stalowych zbiorników cylindrycznych na paliwa płynne. Na podstawie badań doświadczalnych określono ryzyko powstania delaminacji kompozytu stalowo-laminatowego na skutek działania obciążeń o charakterze dynamicznym, a także wpływ zróżnicowanej temperatury, w jakiej pracuje laminat wewnątrz zbiornika, na twardość wykonanej z niego powłoki naprawczej. Dokonano również oceny stabilności wymiarów i kształtu powłoki laminatowej w warunkach wyjątkowych, w których poddawana jest ona ekspozycji na podwyższoną temperaturę. Podjęto także próbę odpowiedzi na pytanie dotyczące wpływu zastosowania powłoki laminatowej na nośność płaszcza zbiornika wzmocnionego z jej użyciem.

EN

The article presents the course and results of research which purpose was aimed at evaluation of selected properties of polyester-glass coatings used to repair and strengthen the jackets of steel cylindrical tanks with a vertical axis for the storage of liquid fuels. Through experimental research, the issues related to the risk of delamination of the steel-laminate composite as a result of dynamic loads, as well as the impact of different temperatures at which the laminate operates inside the tank on the hardness of the laminate coating were identified. The stability of the dimensions and shape of the laminate coating in exceptional conditions where it is subjected to an exposure to elevated temperature was also assessed. An attempt was also made to answer the question about the impact of the use of a laminate coating on the load bearing capacity of the tank shell strengthened with it.

2

Effects of infill density on mechanical properties of additively manufactured chopped carbon fiber reinforced PLA composites

Mayandi K., Rigesh K., Nagarajan Rajini, Ismail Sikiru O., Krishnan Kumar, Mohammad Faruq, Al-Lohedan Hamad A.

Materials Science Poland

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2024

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Vol. 42, No. 1

42--51

EN

In this present study, the fused deposition modeling (FDM) method was used to fabricate the composites. Before three-dimensional (3D) printing, samples were designed according to the ASTM D256, D790 and D3039 standards for impact, flexural and tensile tests, respectively, using Onshape software before conversion to an STL file format. Afterward, the digital file was sliced with infill densities of 60%, 80%, and 100%. The composite samples contained chopped carbon fiber (cCF) and poly lactic acid (PLA), as reinforcement and matrix, respectively. The cCF/PLA (simply called cCFP) filaments were printed into various cCFP composite (cCFPC) samples, using a Viper Share bot 3D machine with different infill densities before the aforementioned mechanical testing. The tensile strength of cCFP were obtained as 25.9MPa, 26.9MPa and 34.75MPa for 60%, 80% and 100% infill density cCFP samples, respectively. Similarly, the flexural strength of cCFP were obtained as 11.8MPa, 12.55MPa and 18.4MPa and impact strength was 47.48kJ/m2, 48.45kJ/m22 for 60%, 80% and 100% infill density cCFP samples, respectively. The fractured/tested samples were examined and analyzed under a scanning electron microscope (SEM) to investigate the presence of fiber and void in the tensile sample. Based on the experimental results, it was evident that a high infill density of 100% with the highest reinforcement exhibited maximum impact strength, tensile and flexural strengths and moduli when compared with other lower carbon content of cCFPC samples. Therefore, the optimal 3D-printed cCFPC sample could be used for engineering application to benefit from properties of the polymer matrix composite materials and possibilities through additive manufacturing (AM).

3

Insights into the processing, structure, and mechanical performance of polyethylene/gypsum composites

Hejna Aleksander, Barczewski Mateusz, Kosmela Paulina, Mysiukiewicz Olga

Composites Theory and Practice

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2024

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R. 24, nr 1

7--24

EN

Polymer composites are used in all branches of industry, with numerous applications. Despite the many years of modifying commodity polymers, using novel fillers allows the range of their applicability to be extended. The impact of new types of fillers on the polymer matrix is not always predictable and requires further studies. The presented study analyzed the application of gypsum as a filler for composites based on high-density polyethylene (PE). The filler was introduced in the amounts of 1-20 wt.%, and its impact on the processing, static, and dynamic mechanical performance of the composites was investigated. At lower filler loadings, the composites could be processed without any hindrance of flowability compared to the neat PE. Up to 5 wt.%, the tensile strength was maintained at a similar level to PE due to the satisfactory quality of the interface and good interfacial adhesion. Higher loadings caused a drop in the tensile strength with a simultaneous rise in Young’s modulus. A further increase in the filler loading resulted in higher values of porosity and growth of the adhesion factor, determinedfrom the dynamic mechanical results, which led to deterioration of the mechanical performance.

4

Refinement of the Manufacturing Route and Evaluation of the Reinforcement Effect of MAX Phases in Al Alloy Matrix Composite Materials

Dmitruk Anna, Naplocha Krzysztof, Żak Andrzej, Strojny-Nędza Agata

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

141--148

EN

Microwave Assisted Self-propagating High-temperature Synthesis (MASHS) was used to prepare open-porous MAX phase preforms in Ti-Al-C and Ti-Si-C systems, which were further used as reinforcements for Al-Si matrix composite materials. The pretreatment of substrates was investigated to obtain open-porous cellular structures. Squeeze casting infiltration was chosen to be implemented as a method of composites manufacturing. Process parameters were adjusted in order to avoid oxidation during infiltration and to ensure the proper filling. Obtained materials were reproducible, well saturated and dense, without significant residual porosity or undesired interactions between the constituents. Based on this and the previous work of the authors, the reinforcement effect was characterized and compared for both systems. For the Al-Si+Ti-Al-C composite, an approx. 4-fold increase in hardness and instrumental Young's modulus was observed in relation to the matrix material. Compared to the matrix, Al-Si+Ti-Si-C composite improved more than 5-fold in hardness and almost 6-fold in Young's modulus. Wear resistance (established for different loads: 0.1, 0.2 and 0.5 MPa) for Al-Si+Ti-Al-C was two times higher than for the sole matrix, while for Al-Si+Ti-Si-C the improvement was up to 32%. Both composite materials exhibited approximately two times lower thermal expansion coefficients than the matrix, resulting in enhanced dimensional stability.

5

Selected issues concerning the use of Shredded Rubber Waste (SRW) in binder-bound mixtures

Walotek Konrad, Bzówka Joanna, Ciołczyk Adrian

Archives of Civil Engineering

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2024

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Vol. 70, nr 2

79--95

EN

This paper presents the results of a composite consisting mainly of industrial waste bound by a hydraulic binder. The composite consists of unburnt coal-mining slate, shredded rubber waste (SRW), fly ash and CEM I cement. The purpose of using the above components was to protect the unburnt coal-mining slate from the negative effects of water, which causes degradation of the aggregate grain size and significantly affects the load-bearing capacity of the aggregate. This was achieved through the use of a binder consisting of shredded waste rubber, fly ash and cement, which imparts hydrophobic properties to the composite. The composite is to be used in road pavement construction and earthworks as a substitute for standard materials. This paper focuses on testing the effects of 5, 10 and 15% additions of shredded rubber waste (SRW) on the physical and mechanical parameters of the composite, mainly compressive strength, water absorption by mass, capillary rise and deformability under cyclic loading. The composite was tested under cyclic loading conditions using a measurement system based on digital image correlation (DIC), with which the deformations occurring on the surface of the test specimens were determined. The results obtained showed the influence of shredded rubber waste additives on the decrease in compression strength (after 7 and 28 days of specimen care), mass water absorption and capillary rise, as well as an increase in the deformability of the composite under destructive loading and cyclic loading.

PL

W pracy przedstawiono wyniki badań kompozytu składającego się głównie z odpadów przemysłowych, związanych spoiwem hydraulicznym. W skład mieszanki wchodzą: łupek przywęglowy nieprzepalony, rozdrobnione odpady gumowe, popiół lotny oraz cement CEM I. Celem zastosowania powyższych składników było zabezpieczenie łupka przywęglowego nieprzepalonego przed negatywnym wpływem wody, który powoduje degradację uziarnienia kruszywa, co znacząco wpływa na nośność kruszywa. Osiągnięto to poprzez zastosowanie spoiwa składającego się z rozdrobnionych odpadów gumowych popiołu lotnego oraz cementu, które powoduje nadanie kompozytowi właściwości hydrofobowych. Mieszanka może być wykorzystana w konstrukcji nawierzchni drogowej oraz w robotach ziemnych, jako substytut standardowo wykorzystywanych materiałów. W artykule skupiono się na badaniach wpływu 5, 10 oraz 15% dodatków rozdrobnionych odpadów gumowych na parametry fizykomechaniczne kompozytu, głównie wytrzymałość na ściskanie, nasiąkliwość masową, podciąganie kapilarne wody oraz odkształcalność pod wpływem cyklicznego obciążenia. W ramach testów kompozytu w warunkach cyklicznego obciążenia został wykorzystany system pomiarowy opierający się na cyfrowej korelacji obrazu (DIC), za pomocą którego określono odkształcenia zachodzące na powierzchni badanych próbek. Uzyskane wyniki badań pozwoliły stwierdzić wpływ dodatków rozdrobnionych odpadów gumowych na zmniejszenie się wytrzymałości na ściskanie (po 7 oraz 28 dniach pielęgnacji próbek), nasiąkliwości masowej i wysokości podciągania kapilarnego oraz podwyższenie odkształcalności kompozytu pod wpływem obciążeń niszczących, jak i obciążenia cyklicznego. Zaprezentowany kompozyt ze względu na swój skład, w którym wykorzystuje się głównie odpady przemysłowe dobrze wpisuje się w gospodarkę o obiegu zamkniętym oraz pozwala na znalezienie nowego sposobu wykorzystania odpadów górniczych, których utylizacja ciągle stanowi problem w Zagłębiu Górnośląskim.

6

The Effect of Cryogenic Cycling on the Mechanical Properties of Epoxy-Glass Composites

Krzak Anna, Nowak Agnieszka J., Gołombek Klaudiusz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 4

149--162

EN

Glass-epoxy laminates are characterized by exceptional properties such as high thermal insulation, resistance to mechanical damage, and stability at low temperatures. These crucial characteristics make them suitable for diverse applications, including cryogenics. Their application in cryogenics allows them to maintain low temperatures in research and industrial processes. This article ana-lyzes the effect of cryogenic cycles on the functional properties of composite materials. The study investigated the influence of cryogenic cycles on the mechanical properties of glass-epoxy laminates. Three sets of cycles were employed, each consisting of 1, 5, and 10 cycles. After each set of cycles, the mechanical properties, including impact strength, flexural strength, and Young's modulus, were measured and compared. Additionally, after each series, scanning electron microscopy (SEM) was used to carefully observe the material's surface and detect possible changes in its appearance and structure, such as cracks or deformations. Conclusions from the conducted research provide essential information on the correlation between cryogenic cycles and the functional properties of composites obtained by coating. The research results can be used to design and improve these materials in various industrial applications. This work determines the effect of a different composition of resin reinforced with glass fabric weighing 205 g/m2 on the mechanical properties of composite materials subjected to cryogenic cycles. This research aims to create innovative materials adapted to work in cryogenic environments.

7

Temperature Effect on Buckling Properties of Thin-Walled Composite Profile Subjected to Axial Compression

Falkowicz Katarzyna, Kuciej Michał, Święch Łukasz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 3

305--313

EN

This study investigates the influence of temperature variations on the buckling properties of thin-walled omega-profiles fabricated from carbon-epoxy composite materials. Utilizing a MTS testing machine, compression tests were conducted on these profiles at temperatures ranging from -20°C to 80°C, in 20°C increments. The primary objective was to assess how temperature fluctuations impact the buckling load and load-bearing capacity of these composite profiles under axial compression. The experimental setup allowed for precise measurement of load-displacement and load-deflection characteristics, and the critical load at which buckling initiation occurred. Observations revealed that the buckling resistance of the profiles exhibited a complex dependence on temperature. At lower temperatures, the composite material demonstrated enhanced stiffness and strength, marginally increasing buckling resistance. Conversely, at elevated temperatures, a noticeable degradation in mechanical properties was observed, leading to a reduced buckling load and altered failure modes. To complement the experimental findings, a comprehensive finite element (FE) analysis was conducted for sample in room temperature. The FE model, developed to replicate the experimental conditions closely, employed an eigenvalue-based approach to predict the buckling initiation and progression accurately. The presented results are the results of only preliminary tests and they will be expand about more samples number as well as to determine material properties for various temperatures.

8

Screw Extrusion as a Scalable Technology for Manufacturing Polylactide Composite with Graphene Filler

Kaczor Daniel, Bajer Krzysztof, Raszkowska-Kaczor Aneta, Krasinska Oksana, Domek Grzegorz, Szroeder Paweł

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

226--237

EN

The use of carbon nanomaterials as fillers in the process of obtaining polymer composites by extrusion poses many problems. The high agglomeration ability and low bulk density of carbon nanomaterials do not allow to easy production of composites characterized by very good dispersion of the filler in the polymer matrix, which is required to obtain a high-quality product. The advantage of this type of fillers is that the improvement of the composite properties can be achieved even at a low degree of filling. In this article, we describe a method for obtaining polylactide composites with a nanofiller in the form of graphene nanoplatelets. To overcome the difficulties associated with the use of graphene, we divided the process of obtaining composites into two stages. In the first stage, we made a masterbatch containing 25 wt.% graphene, from which, in the second stage, we obtained target composites containing from 0.1 to 2 wt.% graphene. A twin-screw extruder was used in both stages. The tested filling levels had no significant impact on the recorded processing parameters. The composites obtained by the described method are characterized by good dispersion of graphene. However the graphene agglomerates can be observed in the polymer matrix. Composites were tested by SEM, FTIR, DSC and MFR methods. Mechanical tests such as static tension, three-point bending, impact strength showed that the addition of 0.5 wt% of graphene improves tensile strength by 10 %, Young's modulus by 19 % and both flexural strength and flexural modulus by 15 %. The carbon filler has an impact on crystallization process of the polymer matrix by acting as a nucleating agent.

9

Screw Extrusion as a Scalable Technology for Manufacturing Carbon Nanotube-Filled Polylactide Composites

Kaczor Daniel, Bajer Krzysztof, Raszkowska-Kaczor Aneta, Domek Grzegorz, Schroeder Paweł

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 3

99--110

EN

The bottleneck in the widespread use of carbon multiwall nanotube polymer composites is the lack of manufacturing technology that can be used on an industrial scale. In this article, we describe a two-step composite manufacturing technology based on screw extrusion that produces composites characterizing with good dispersion of carbon nanotube filler in polylactide matrix. The first stage involved the fabrication of highly filled masterbatches of 25 wt% of carbon nanotubes. In the second stage, by screw extrusion of the masterbatch mixture with neat polymer, we obtained homogeneous composites with the target filler concentration. The resulting composites with nanotube content ranging from 0.1 to 2 wt%. Mechanical tests including static tension, tensile strength, tensile modulus, three-point bending and impact strength has shown that optimal concentration of the carbon nanotube filler is ranged between 0.5 and 1 wt%. Samples were examined also by SEM, FTIR-ATR, DSC and MFR methods.

10

Characterization of the Mechanical Behavior of Hemp-Clay Composites

Haboubi Chaimae, Barhdadi El Hassane, Haboubi Khadija, Hammoudani Yahya El, Sadoune Zouhair, El Abdouni Aouatif, Dimane Fouad

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 2

71--77

EN

In the present study, micromechanical modeling techniques were employed to examine the mechanical properties of a hemp/clay composite material. This composite consists of hemp fibers incorporated into a clay matrix, a configuration chosen in response to environmental considerations and the natural advantages of hemp fibers, which include their lightweight nature and their considerable strength and stiffness relative to their weight. The approach adopted incorporates both localization and homogenization methodologies along with the three-phase model to provide an in-depth analysis of the composite's behavior. The findings from this theoretical model show a promising correlation with empirical data, demonstrating the model's efficacy in capturing the composite's mechanical response.

11

Analysis of the Effect of Vacuum Pressure Variations on the Fluidity, form Ability, Hardness, and Density of the RTV 10A Silicon Rubber Composites with 30% Talc

Suprihanto Agus, Caesarendra Wahyu, Wibowo Dwi Basuki, Bartoszuk Marian, Varga Gyula

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 4

12--22

EN

RTV 10A silicone rubber composites have many applications in forming many medical products and one of the recent applications is for orthotic insoles. This is because the RTV silicon rubber has excellent flexibility, elasticity, and resistance against splitting. However, these mechanical properties still need improvement when applied in certain medical applications. One way to improve mechanical properties is by adding talc. The process of mixing silicon rubber with talc requires special techniques to prevent the formation of porosity that may lead to unexpected mechanical properties. This porosity occurs due to trapped air during the mixing process or pouring into molds. Efforts to eliminate this porosity include Vacuum Die Casting (VDC) techniques. This study presents the mechanical properties improvement of RTV 10A silicon rubber composite with the addition of using 30% talc. The objective is to achieve a more convenient orthotic insole to reduce the pain in human foot joints during walking due to planar stress. This study aims to reduce the porosity and minimize the trapped air by adding 30% talc into RTV 10A silicone rubber composite using VDC. In the experiment, the pressure variation was determined at -0.04 MPa, -0.06 MPa, -0.08 MPa, and -0.1 MPa through a mold size of 45 mm in diameter and thickness of 7 mm. Fluidity, density, porosity, and hardness were tested during the experiment. The results show that by decreasing vacuum pressure, the density and the hardness increase. This is because the size and distribution of porosity are decreased and more homogeny. Furthermore, it also produces higher fluidity. However, the porosity of the specimen after vacuum casting is not partially filled.

12

A study of basalt-composite reinforcement of Georgian production and standard preparation

Khmelidze Tamaz, Kikadze Vladimer, Rajczyk Marlena

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2023

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Z. 29 (179)

48--52

EN

Analyzing the development of the modern construction industry clearly shows the steady increase in the share of load-bearing and enclosing structures made based on building materials obtained by new technology. Polymer-based composites have a special place in this range of materials. The use of composite materials in construction can solve such important issues as reducing operating costs and the mass of buildings, improvement of technical characteristics of structures, serviceability, strength, deformation, thermal insulation, operational properties, etc. The advantage of composites include: the construction of structures, elements and details with predetermined properties that meet working conditions and requirements. The variety of fibers and matrix materials, as well as the optimization of reinforcement schemes used to create the composite structures, give the engineers complete freedom to adjust the properties of the composite material accordingly at the expense of changing the component ratio and macro-structure. Hundreds of thousands of natural (non-composite) and artificial materials are now known. However, they can no longer meet the increased demands.

PL

Analizując rozwoj wspołczesnego budownictwa, wyraźnie widać stały wzrost udziału konstrukcji nośnych i osłonowych wykonywanych w oparciu o materiały budowlane otrzymywane z wykorzystaniem nowej technologii. Kompozyty na bazie polimerow zajmują szczegolne miejsce w tej gamie materiałow. Zastosowanie materiałow kompozytowych w budownictwie może rozwiązać ważne problemy, takie jak: zmniejszenie kosztow eksploatacji i masy budynkow, poprawa właściwości technicznych konstrukcji - użyteczności, wytrzymałości, odkształceń, izolacyjności termicznej, właściwości eksploatacyjnych itp. Zaletą kompozytow jest: swoboda w konstruowaniu elementow i detali o określonych właściwościach, spełniających warunki i wymagania pracy. Rożnorodność włokien i materiałow osnowy, a także optymalizacja schematow zbrojenia stosowanych przy tworzeniu struktur kompozytowych dają inżynierom pełną swobodę w zakresie odpowiedniego dostosowywania właściwości materiału kompozytowego kosztem zmiany proporcji składnikow i makrostruktury. Obecnie znane są setki tysięcy materiałow naturalnych (niekompozytowych) i sztucznych. Nie są one jednak w stanie sprostać rosnącym wymaganiom przemysłu i gospodarki.

13

The application of composites based on recycled materials for electromagnetic field shielding

Jakubas Adam, Łada-Tondyra Ewa, Suchecki Łukasz

Przegląd Elektrotechniczny

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2023

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R. 99, nr 1

190--193

EN

This paper presents the possibilities of using polymer-metal composites as electromagnetic shields. Recycled materials such as iron scale and nanocrystalline tapes were used to build the composites. In the course of the work, research was carried out into the effectiveness of shielding electromagnetic fields in the range from 40 Hz to 15 GHz. The shielding effectiveness was shown to be competitive to that of other composite materials based on non-metallic fillers and comparable to that of layered composites containing e.g. aluminum.

PL

W artykule przedstawiono możliwości wykorzystania kompozytów polimerowo-metalowych jako ekranów elektromagnetycznych. Do budowy kompozytów wykorzystano materiały z recyklingu, takie jak zendra i taśmy nanokrystaliczne. W toku prac prowadzono badania nad skutecznością ekranowania pól elektromagnetycznych w zakresie od 40 Hz do 15 GHz. Wykazano, że skuteczność ekranowania jest konkurencyjna w stosunku do innych materiałów kompozytowych na bazie wypełniaczy niemetalicznych i porównywalna z kompozytami warstwowymi zawierającymi m.in. aluminium.

14

Właściwości mechaniczne betonów z dodatkiem makrowłókien poliolefinowych

Helbrych Paweł

Przegląd Budowlany

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2023

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R. 94, nr 11-12

54--57

PL

W artykule przedstawiono wyniki badań wpływu dwóch typów makrowłókien poliolefinowych na właściwości świeżego i stwardniałego betonu. Określono zawartość powietrza w mieszance betonowej, klasę konsystencji, wytrzymałość na ściskanie, wytrzymałość betonu na rozciąganie w próbie zginania oraz wytrzymałość na rozciąganie przy rozłupywaniu. Wykazano istotny wpływ rodzaju, kształtu i budowy włókien syntetycznych na właściwości mechaniczne betonu. Dodatek włókien poliolefinowych nie wpłynął negatywnie na wytrzymałość na ściskanie betonu, a serie badawcze z mniejszą ilością włókien fibrylowanych uzyskały podobne lub lepsze wyniki wytrzymałościowe niż serie z większą ilością foliowłókien. Wyniki te wskazują na potencjał wykorzystania makrowłókien polimerowych w konstrukcjach betonowych, co pozwoli na poprawę jego wytrzymałości i innych istotnych właściwości.

EN

The article presents the results of research on the influence of two types of polyolefinic macrofibers on the properties of fresh and hardened concrete. The content of air in the concrete mix, consistency class, compressive strength, tensile strength of concrete in flexural testing, and splitting tensile strength were determined. The significant impact of the type, shape, and structure of synthetic fibers on the mechanical properties of concrete has been demonstrated. The addition of polyolefin fibers did not have a negative effect on the compressive strength of concrete, and research series with a smaller amount of fibrillated fibers achieved similar or better strength results than series with a larger amount of film fibers. These results indicate the potential use of polymer macrofibers in concrete structures, which will allow for the improvement of its strength and other important properties.

15

Comparative Studies of GFRP Composites Using Pulsed Thermography and Transmission Terahertz Non-Destructive Testing Methods

Świderski Waldemar, Strąg Martyna

Pomiary Automatyka Robotyka

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2023

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R. 27, nr 3

33--37

EN

Composites are materials that have replaced traditional construction materials in numerous applications in various fields. Due to the possibility of creating the required material properties, fiber-reinforced composites are most often used. Despite competition from carbon and aramid fibers, the earliest glass fibers produced are used in many applications. One of the areas where glass fiber reinforced composites (GFRP) make a significant contribution to structural applications is aviation. Because both during production and operation, composites are exposed to damage, which often occurs in the internal structure of the composite, works are being carried out to develop the most effective method of non-destructive testing to detect such damage. The article presents a comparison of the results of non-destructive testing of glass fiber-reinforced composite samples. A comparison of the results of the possibility of detecting defects in the form of milled holes of different diameters and depths inside the samples was made. These damages are not optically visible on both surfaces of the samples. In non-destructive testing, infrared thermography and transmission terahertz methods were used. The obtained results indicate a great possibility of using terahertz radiation, especially in thicker structures of the GFRP composite, where thermographic methods are not as effective as in thin ones.

PL

Kompozyty to materiały, które zastąpiły tradycyjne materiały konstrukcyjne w licznych zastosowaniach w różnych dziedzinach. Ze względu na możliwość tworzenia wymaganych właściwości materiału, najczęściej stosuje się kompozyty wzmacniane włóknami. Pomimo konkurencji ze strony włókien węglowych i aramidowych, najwcześniej wyprodukowane włókna szklane są wykorzystywane w wielu zastosowaniach. Jednym z obszarów, w którym kompozyty wzmocnione włóknem szklanym (GFRP) wnoszą znaczący wkład w zastosowania konstrukcyjne, jest lotnictwo. Ponieważ zarówno w trakcie produkcji, jak i eksploatacji kompozyty narażone są na uszkodzenia, które często występują w strukturze wewnętrznej kompozytu, prowadzone są prace nad opracowaniem najskuteczniejszej metody badań nieniszczących pozwalających wykryć takie uszkodzenia. W artykule przedstawiono porównanie wyników badań nieniszczących próbek kompozytów wzmocnionych włóknem szklanym. Dokonano porównania wyników możliwości wykrywania defektów w postaci wyfrezowanych otworów o różnej średnicy i głębokości wewnątrz próbek. Uszkodzenia te nie są widoczne optycznie na obu powierzchniach próbek. W badaniach nieniszczących wykorzystano termografię w podczerwieni i transmisyjną metodę terahercową. Uzyskane wyniki wskazują na duże możliwości wykorzystania promieniowania terahercowego, zwłaszcza w grubszych strukturach kompozytu GFRP, gdzie metody termograficzne nie są tak skuteczne jak w strukturach cienkich.

16

Experimental research on the removal characteristics of simulated radioactive aerosols by a cloud-type radioactive aerosol elimination system

Zhang Jiqing, Jia Ying, Lv Xiaomeng, Xiong Tiedan, Huang Yuanzheng, Shen Keke

Polish Journal of Chemical Technology

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2023

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Vol. 25, nr 4

10--18

EN

Radioactive aerosols in the confined workplace are a major source of internal exposure hazards for workers. Cloud-type radioactive aerosol elimination system (CRAES) have great potential for radioactive aerosol capture due to their high adsorption capacity, lack of cartridges and less secondary contamination. A CRAES was designed and constructed, and a FeOOH/rGO composite was directly prepared by a hydro-thermal method to characterise and analyse its morphology, chemical structure and removal efficiency for simulated radioactive aerosols. The results show that the FeOOH/rGO composite works in synergy with the CRAES to effectively improve the removal efficiency of simulated radioactive aerosols. A 30-minute simulated radioactive aerosol removal rate of 94.52% was achieved when using the experimentally optimized composite inhibitor amount of 2 mg/L FeOOH/rGO with 0.2 g/L PVA as a surfactant. Therefore, the CRAES coupled with the composite inhibitor FeOOH/rGO has broad application potential for the synergistic treatment of radioactive aerosols.

17

Uwiarygodnienie koncepcji „projektowania plastycznego” belek mostowych zgodnie z Eurokodem 4: Badania niszczące w skali naturalnej zespolonych belek mostowych złożonych z dwuteownika HL1100 i płyty betonowej

Marcinczak Krzysztof, Kożuch Maciej, Lorenc Wojciech, Zannon Riccardo, Ochojski Wojciech

Mosty

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2023

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nr 3

47-50

PL

W artykule przedstawiono wyniki eksperymentów niszczących, które rzucają nowe światło na projektowanie mostów zespolonych w Polsce. Różnica między tradycyjnymi normami a nowoczesnym podejściem opartym na Eurokodzie 4 jest widoczna. Wyniki badań opisane przez autorów stanowią solidny argument za zmianą tradycyjnych praktyk.

EN

The article presents the results of destructive experiments, which shed new light on the design of composite bridges in Poland. The difference between traditional norms and a modern approach based on Eurocode 4 is evident. The test findings described by the authors provide a strong argument for changing traditional practices.

18

Friction films analysis and tribological properties of composite antifriction self-lubricating material based on nickel alloy

Roszak Maciej Robert, Kurzawa Adam, Roik Tetiana, Gavrysh Oleg, Vitsiuk Iulia, Barsan Narcis, Pyka Dariusz, Bocian Mirosław, Jamroziak Krzysztof

Materials Science Poland

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2023

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Vol. 41, No. 3

1--17

EN

This article analyzes the composition and distribution of chemical elements in friction films and their effect on the tribological properties of the self-lubricating, high-temperature antifriction composite based on EP975 powder nickel alloy with CaF2 solid lubricant. Analysis of the chemical elements by energy-dispersive spectroscopy (EDS) showed their uniform distribution, on both the composite’s surface and the counterface’s surface. The alloying elements’ uniform distribution leads to a uniform distribution of the corresponding phases and structural elements in the antifriction film. This ensures high tribological properties at high temperatures. Analysis of the material’s tribological properties, by means of metallographic and micro-X-ray research confirmed the correctness of the technology for producing the composite. Solid lubricant CaF2, alloying elements, and their corresponding phases form the continuous antiscoring film. The film influences the antifriction properties formation during the friction process and provides a self-lubricating mode under the action of high temperature and oxygen. Antiscoring, self-lubricating CaF2 films minimize wear of the friction pairs and defend the contact surfaces against intensive wear. The dense antifriction films have smooth microtopography, which stabilizes the high-temperature friction unit operation. Thus, the self-lubrication mode is realized for a long exploitation time. Tribological properties analysis allowed us to determine the ranges of rational exploitation modes for the material being studied: a load up to 5.0 MPa, a slide speed from 0.3 to 1.0 m/s, a temperature up to 800°C, in the air. The results obtained opened the opportunity to control the antifriction film formation and the composite’s tribological properties by the choice of the initial ingredients while taking into account the operating conditions.

19

Application of Taguchi methods (doe) in composite engineering

Lesiuk Grzegorz, Zielonka Paweł, Olaleye Kayode, Soogabbe Japhet, Lafarga Adrian Ferrer

Journal of TransLogistics

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2023

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Vol. 19

51-61

EN

In the paper, a design of experiment (DOE) in terms of the Taguchi method was used for the optimization of the manufacturing process. This approach makes it possible to do fewer experiments while still getting the desired outcomes. This research programme will use this tool to optimize the resin casting process by monitoring manufacturing parameters like temperature, curing time, and flameretardant concentration. Thus, this study aims to determine the ideal set of parameters for the resin casting of composite materials. Based on experimental results, it was possible to find crucial factors and their influence on the fracture strength of resin for composite manufacturing systems.

20

Development of lightweight geopolymer composites containing perlite and vermiculite

Korniejenko K., Pławecka K., Bulut A., Şahin B., Azizağaoğlu G., Figiela B.

Journal of Achievements in Materials and Manufacturing Engineering

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2023

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Vol. 117, nr 2

49--56

EN

Purpose: The aim of this work was to prepare and characterise geopolymer composites containing lightweight aggregates - perlite and vermiculite. Design/methodology/approach: The geopolymer matrix was prepared on the basis of fly ash, sand and a 6M sodium hydroxide solution with sodium silicate. The properties of the materials were tested 28 days after the preparation of the samples. The following research methods were used to characterise the composites: compressive and flexural strength tests, microstructural tests using a scanning electron microscope, and thermal conductivity were measured. Findings: The results obtained showed a slight effect of the additives on the strength properties. Lightweight aggregates are characterised by good coherence with the matrix material. Their addition allowed to reduce the density and lowered the thermal conductivity of the materials. The results obtained indicate that the proposed additives can improve the properties of the geopolymer composite for use in the construction industry. Research limitations/implications: Further research should focus on geopolymer composites with perlite and involve fire-resistant and water-absorption tests. Practical implications: The production of lightweight building materials brings a number of benefits, such as reducing the density of building elements and, at the same time, the entire structure, which results in a reduction in their weight, as well as lower transport costs. Such elements have better thermal and acoustic insulation, reflected in the parameters of buildings. An additional advantage is the reduced environmental impact through better insulation properties, lower fuel consumption during transport, etc. Originality/value: The density of the material can be reduced by using lightweight aggregates or obtaining porous material in the foamed process. In the case of geopolymer composites, a number of studies related to foamed materials have been provided, but there is only a few previous research connected with lightweight aggregates such as perlite and vermiculite.