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1

Hybrid polymer materials with substantially improved mechanical properties

Sanocki Tadeusz, Sanocki Marek, Sanocka-Zajdel Agnieszka, Majcherczyk Henryk, Zajdel Magdalena, Bulanda Katarzyna, Oliwa Rafał, Oleksy Mariusz, Budzik Grzegorz, Stącel Monika

Polimery

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2025

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Vol. 70, nr 3

194--203

EN

The results of the research project POIR.01.01.01-00-0760/18 implemented from the funds of the Smart Growth Operational Program in the years 2014-2020 entitled “Development of a new technology for manufacturing details from polymer materials with significantly improved mechanical and visual properties” at Splast Ltd. were presented. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to assess the structure of the composites. The strongest interactions at the composite-coating interface were observed in the case of the use of varnish (interphase boundary width). The composites were characterized by gloss in the range of 32.6-448 GU, which classifies them as semi-gloss or glossy materials. SEM micrographs confirmed the correctness of the selection of materials, as evidenced by good fiber dispersion in the polymer matrix, while maintaining a characteristic round shape.

PL

Przedstawiono wyniki badań projektu POIR.01.01.01-00-0760/18 realizowanego ze środków Programu Operacyjnego Inteligentny Rozwój w latach 2014-2020 pt. „Opracowanie nowej technologii wytwarzania detali z materiałów polimerowych o znacząco poprawionych właściwościach mechanicznych i wizualnych” w Splast Sp. z o.o. Do oceny struktury kompozytów użyto mikroskopię sił atomowych (AFM) i skaningową mikroskopię elektronową (SEM). Najsilniejsze oddziaływania na granicy faz kompozyt-powłoka zaobserwowano w przypadku zastosowania powłoki lakierniczej (szerokość granicy międzyfazowej). Kompozyty charakteryzowały się połyskiem w zakresie 32,6-448 GU, co klasyfikuje je jako materiały z półpołyskiem lub połyskiem. Mikrofotografie SEM potwierdziły poprawność doboru materiałów, o czym świadczy dobra dyspersja włókna w osnowie polimerowej, przy zachowaniu charakterystycznego okrągłego kształtu.

2

Zastosowanie cyfrowej korelacji obrazu do analizy pola przemieszczeń stalowych belek cienkościennych typu sigma wzmacnianych tkaniną z włókna węglowego

Rzeszut Katarzyna, Dybizbański Maciej Adam

Inżynieria i Budownictwo

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2025

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R. 81, nr 3

282--292

PL

W niniejszej pracy przedstawiono wyniki badań laboratoryjnych przeprowadzonych metodą cyfrowej korelacji obrazu ARAMIS 6M. Pomiar przemieszczeń oraz ocena deformacji została przeprowadzona dla belek CFS o przekroju Σ200×70×2 i rozpiętości 2700 mm, wykonanych ze stali S350GD. Testy czteropunktowego zginania przeprowadzono dla belek wzmocnionych i niewzmocnionych (belki referencyjne). Wzmocnienie wykonano przy użyciu tkaniny SikaWrap 230 C przyklejonej do zagięć brzegowych klejem SikaDur 330. Badania przeprowadzono dla dwóch przypadków: dla podpór z możliwością deplanacji przekroju i dla podpór ze skrępowaną deplanacją. Na podstawie uzyskanych wyników stwierdzono, że zarówno w przypadku przemieszczeń pionowych, jak i poziomych zastosowanie zaproponowanego wzmocnienia ma szczególnie korzystny wpływ wówczas, gdy na podporach nie ma możliwości deplanacji przekroju.

EN

This paper presents the results of laboratory tests obtained using the ARAMIS 6M digital image correlation method. The displacement measurement and deformation assessment were carried out for CFS beams with a cross-section of Σ200×70×2 and a span of 2700 mm, made of S350GD steel, reinforced and unreinforced (reference), loaded in a four-point bending scheme. The beams were reinforced with SikaWrap 230 C fabric glued to the edge stiffeners using SikaDur 330 adhesive. The tests were carried out for two cases, i.e., with the possibility of cross-section deplanation at the supports and for the lack of deplanation at the supports. Based on the obtained results, it was found that in the case of vertical and horizontal displacements, the use of the proposed reinforcement has a particularly beneficial effect for the case when there is no possibility of cross-section deplanation at the supports.

3

Studying the metakaolin content, fiber type, and high-temperature effects on the physico-mechanical properties of fly ash-based geopolymer composites

Bayrak Bariş, Alcan Haluk Görkem, Durmaz Özge Çiğdem Özelmacı, ipek Süleyman, Kaplan Gökhan, Güneyisi Erhan, Aydın Abdulkadir Cüneyt

Archives of Civil and Mechanical Engineering

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2025

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Vol. 25, no. 1

art. no. e2, 2025

EN

The study investigated the physicasl characteristics and mechanical performance of fly ash-based geopolymer composites when exposed to high temperatures. Geopolymer composites were produced using fly ash as an aluminosilicate-rich raw material and a combination of sodium silicate and sodium hydroxide as an alkaline activator. In this context, the study also examined the impact of partially replacing metakaolin (7.5% and 15% by weight). Furthermore, the study aims to examine the impact of adding fiber (basalt and carbon types) on the physical, mechanical, and high-temperature properties of geopolymer composites. The physical properties investigated were unit weight, apparent porosity, water absorption, and capillary water absorption, while the strength performances investigated were flexural and compressive strengths. To monitor the effect of high temperatures on the strength characteristics of the geopolymer composites, the mixtures were exposed to temperatures of 200 °C, 400 °C, and 600 °C. Besides, SEM images were provided to illustrate the degree of geopolimerization. The results indicated that metakaolin replacement yielded mixtures having higher unit weight, but lower apparent porosity and water absorption. The results indicated that metakaolin replacement yielded mixtures having a higher unit weight, reaching an increase of about 5%, but lower apparent porosity and water absorption, with decreases reaching 18.3% and 20%, respectively. The metakaolin-blended geopolymer composites resulted in better strength performance and resistance to high temperatures. Raising the metakaolin replacement level from 0 to 15% led to an increase of 17.3% in flexural strength. The compressive strength of the composites subjected to a temperature of 200 °C exhibited an increase of over 10%. Notably, this rate of increment was observed to be nearly 20% higher in nonfibrous composites. Fiber addition decreased the compressive strength up to about 21%, while increasing the flexural strength up to 65%. Strength performance improved at 200 °C, but decreased at higher temperatures up to 600 °C. The geopolymer composites experienced significant mass loss when exposed to high temperatures.

4

Use of carbon fiber fabric for reinforcement of bent hot-rolled steel channels

Szewczak Ilona, Snela Małgorzata

Advances in Science and Technology. Research Journal

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2025

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Vol. 19, no. 12

394--401

EN

The widespread application of steel as a structural material in industrial and bridge construction highlights the importance of research into strengthening methods for steel structures made of hot-rolled profiles. This study presents laboratory tests conducted on bent hot-rolled C100 steel channels with a length of 3 meters. A total of eight beams were tested, of which the first two served as unstrengthened reference specimens. The remaining beams were reinforced using bonded carbon fiber fabric in three different configurations. The results of the experimental study indicate a negligible effect of this strengthening method on the increase in ultimate load capacity and strain reduction, while showing an approximate 22% reduction in horizontal displacements compared to the reference beams.

5

Machinability analysis of thin-walled carbon fiber reinforced ceramic composites based on wire electrical discharge machining

Poroś Dariusz, Wiśniewska Magdalena

Zeszyty Naukowe Politechniki Morskiej w Szczecinie

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2024

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nr 77 (149)

5--13

EN

We propose employing wire electrical discharge machining (WEDM) for shaping thin-walled, multidirectional, carbon fiber reinforced silicon carbide (Cf-SiC) composite parts. Ceramic matrix composite Cf-SiC combines the outstanding mechanical properties of the carbon fiber with oxidation, abrasive wear, corrosion resistance, and high strength at the high temperature of the silicon carbide matrix. The impact of time-related electrical discharge machining parameters (pulse ON-time and break OFF-time) on the material removal rate and surface roughness are analyzed. The material removal rate of the Cf-SiC is proved to be 36% lower than that for machined steel grade 55. The high thermal stresses and interaction of the composite accompanying WEDM are also discussed. Furthermore, an alternative mechanism to the WEDM of metals has been investigated and confirmed by a scanning electron microscopy (SEM) analysis. The morphology of the machined Cf-SiC surface demonstrates the dominance of the carbon fibers’ fracture mechanism, both the transverse and longitudinal forms, with interphase detachment over craters and micro-cracks, pitting, and spalling on the SiC matrix. Satisfactory roughness indicators (Sa = 2 µm) are obtained in 3D topography measurements of the Cf-SiC surfaces. Concluding, the WEDM should be considered a good alternative to Cf-SiC abrasive machining when cutting holes, grooves, keyways, splines, and other complex shapes.

6

Experimental of buckling restrained brace hysteretic performance with carbon fiber wrapped in concrete

Fang Yuan, Lv Lei, Gao Yuqiang, Fu Zhongqiu

Archives of Civil Engineering

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2024

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Vol. 70, nr 1

527--541

EN

Buckling restrained brace is an important structure for improving the seismic resistance of structures. Conducting research on new types of buckling restrained brace can improve the seismic performance and reliability of buckling resistant support. Four different types of buckling restrained braces specimens were designed and manufactured: cross-shaped square steel pipe members, cross-shaped round steel pipe members, cross-shaped carbon fiber members, and in-line carbon fiber members. By conducting quasi-static tests, the force displacement hysteresis curves, skeleton curves, stiffness degradation, equivalent viscous damping coefficient, and energy dissipation ratio of four different types of buckling restrained brace were analyzed. The research results showed that all four buckling restrained brace specimens have good hysteresis performance. The load-bearing capacity and energy consumption performance of the three specimens of square steel pipe, round steel pipe and carbon fiber with the same core unit are the same, but the inline type is worse than the cross type. The core unit specimen with a width of 80 mm is about 60% higher in bearing capacity and energy consumption than a specimen with a width of 50 mm. The core unit of some specimens undergoes multi-wave buckling. For carbon fiber specimens, the CFRP is prone to breakage due to the lateral thrust of the restraining unit. Therefore, steel hoop or stirrup should be added to the end to improve the restraint effect when designing and manufacturing.

7

Mechanical Properties of Carbon Fiber Reinforced Materials for 3D Printing of Ankle Foot Orthoses

Rybarczyk Justyna, Górski Filip, Kuczko Wiesław, Wichniarek Radosław, Siwiec Sabina, Vitkovic Nikola, Păcurar Răzvan

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no. 4

191--21

EN

The article presents analysis of mechanical properties of specimens fabricated by fused deposition modeling (FDM). The four of considered materials are the well-known 3D printing filaments i.e., polylactide (PLA), Nylon 12 (PA12), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate glycol (PET-G). The other four of the considered materials are composites with carbon i.e. polylactide with carbon fiber (PLA-CF), Nylon 12 with carbon fiber (PA12-CF), acrylonitrile butadiene styrene with carbon fiber (ABS-CF), polyethylene terephthalate glycol with carbon fiber (PETG-CF). The paper describes how the specimens were designed, printed, subjected to tensile testing, and examined using microscopy. The obtained data will be used to select the optimum material for the rapid manufacture of lower limb orthoses. Carbon composites were found to have better mechanical properties of their base material, but the fabrication of composite samples is much more time consuming, for the reason that the manufacturing process is not stable.

8

Structural integrity of three dimensional printed carbon fiber composites/nanocomposites for aeronautical components—current scenarios and opportunities

Kausar Ayesha

Advances in Materials Science

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2024

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Vol. 24, nr 4(82)

67--97

EN

This state-of-the-art innovatory overview essentially debates practical worth of three-dimensional printed composites/nanocomposites (especially carbon fiber designs) for aerospace sector. Recently, three-dimensional printing (additive manufacturing) has competently transpired for designing high performance space structures. The manuscript systematically frameworks fundamentals of three-dimensional printing approach, ensuing high-tech aeronautical carbon fiber composites/nanocomposite systems, and space components/structural applications. Amongst carbonaceous fillers, short/continuous carbon fibers were inspected as outperforming reinforcements for aerospace. Additionally, surface modified/composited carbon fibers with nanocarbons (carbon nanotube, graphene) have been reported. Accordingly, polyamide, poly(lactic acid), poly(ether ether ketone), epoxies, etc. have been documented as substantial thermoplastic/thermosetting matrices. Ensuing radical polymer/carbon fiber or polymer/carbon fiber/nanocarbon hybrids have benefits regarding low-cost manufacturing, structural precision, complex geometries, high efficiency, least structural defects/voids, superior tensile and shear strength/modulus, compression strength, interlaminar strength, wear properties, thermo-dimensional constancy, and heat stability features, under extreme space environments. Consequently, cutting-edge three-dimensional printed carbon fiber hybrids offered myriad of promising opportunities for mechanically robust (nozzle wearing, strengthened wing spar/ribs, resilient rotating components, interlaminar strength/dimensional stability) and high temperature stable (cryogenic fuel storage, lower earth orbital stability, thermal-dimensional steadiness, thermal conductivity) for aerospace modules. Henceforth, three-dimensional printing owns enormous engineering potential to meet aeronautical manufacturing demands by overcoming challenges of traditional techniques.

9

Nanocomposites of nanocarbon functionalized carbon fibers — manufacturing to methodological applications

Kausar Ayesha, Ahmad Ishaq

Advances in Materials Science

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2024

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Vol. 24, nr 1(79)

46--71

EN

Carbon fibers have been technically applied in high performance materials and industrial scale applications. Importantly, carbon fiber reinforced composite materials have found applications in aerospace industries. These properties of carbon fiber reinforced composites depend upon the carbon fiber features such as length, orientation, surface properties, adhesion with matrices, etc. To improve the surface properties of carbon fibers and adhesion and interactions with polymers, fiber modification has been suggested as an efficient approach. Carbon nanoparticle or nanocarbon functionalized carbon fibers have been manufactured using various facile physical and chemical approaches such as electrospraying, electrophoretic deposition, chemical vapor deposition, etc. Consequently, the modified carbon fibers have nanocarbon nanoparticles such as graphene, carbon nanotube, nanodiamond, fullerene, and other nanocarbons deposited on the fiber surface. These nanocarbon nanoparticles have fine capability to improve interfacial linking of carbon fibers with the polymer matrices. The chemical vapor deposition has been adopted for uniform deposition of nanocarbon on carbon fibers and chemical methods involving physical or chemical modification have also been frequently used. The resulting advanced epoxy/carbon fiber/nanocarbon composites revealed improved tensile and physical profiles. This review basically aims manufacturing and technical aspects of polymer/fiber/nanofiller nanocomposites toward the development of high performance structures. The resulting morphology, strength, modulus, toughness, thermal stability, and other physical features of the nanocarbon functionalized carbon fibers have been enhanced. In addition, the fabricated polymer/fiber/nanofiller nanocomposites have fine interfacial adhesion, matrix-nanofiller-filler compatibility, and other characteristics. The application areas of these nanomaterials have been found wide ranging including the strengthened engineering structures, supercapacitors, shape memory materials, and several others.

10

Competence of carbonaceous fibers/nanofillers (graphene, carbon nanotube) reinforced shape memory composites/nanocomposites towards aerospace — existent status and expansions

Kausar Ayesha

Advances in Materials Science

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2024

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Vol. 24, nr 3(81)

30--55

EN

Shape memory or stimuli responsive polymers have established a unique grouping of smart materials. The technical merit of these polymers has been evaluated in aerospace sector, since last few decades. Particularly, the stimuli responsive polymers render inherent competences to recuperate the structural damages in exterior/interior space architectures. In this context, both the thermoplastics as well as thermosetting polymers depicted essential stimuli responsive behaviour. As interpreted in this state-of the-art review, the carbonaceous reinforcement like carbon fibers and nano-reinforcements including nanocarbons (graphene, carbon nanotube) have been employed in the shape recovering matrices. The performance of ensuing shape retrieving aerospace materials was seemed to be reliant on the polymer chain crosslinking effects, filler/nanofiller dispersal/alignment, microstructural specs, interfacial contour and interactions, and processing techniques used. Consequently, the shape actuations of polymer/carbon fiber composites were found to be instigated and upgraded through the inclusion of nanocarbon nano-additives. The ensuing high-tech shape memory composites/nanocomposites have anomalous significance for various aero-structural units (fuselage, wings, antennas, engines, etc.) due to prevention of possible thermal/shock/impact damages. Future implications of carbonaceous shape memory composites/nanocomposites in aerospace demands minimizing the structure-property-performance challenges and large scale fabrication for industrial scale utilizations. In this way, deployment of carbonaceous nanofiller/filler based composites revealed enormous worth due to low density, anti-fatigue/wear, anti-corrosion, non-flammability, self-healing, and extended durability and long life operations. However, there are certain challenges associated with the use of nanocarbons and ensuing nanocomposites in this field markedly the adoption of appropriate carbon fiber coating technique, aggregation aptitude of nanocarbons, additional processing steps/cost, nanoparticle initiated invisible defects/voids, difficulty in machinability operations due to presence of nanoparticles, and corrosion risk of composite structures in contact with metal surfaces. By overcoming these hinderances, nanoparticles modified carbon fiber based composites can be promising towards a new look of upcoming modernized aerospace industry.

11

Nowe nanomateriały do konstrukcji sprzętu sportowego

Jifang Yuan, Jianguo Chen, Yong Xu

Przemysł Chemiczny

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2023

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T. 102, nr 8

783--794

PL

Nowe nanomateriały dla sprzętu sportowego zostały przygotowane poprzez wzmocnienie żywicy epoksydowej (EP) włóknami węglowymi (CF) i/lub nanorurkami węglowymi (CNT) w celu poprawy jakości, twardości, plastyczności i odporności na starzenie materiałów kompozytowych. CNT zostały równomiernie rozmieszczone poprzez filtrację próżniową i fizyczne osadzanie na powierzchni włókien CF. Wytrzymałość na zginanie kompozytów CF/EP-CNT była o 28,08% większa niż niemodyfikowanego kompozytu CF/EP. Po starzeniu w temp. 120°C naprężenia w kompozycie zostały rozproszone ze względu na doskonałą dyspergowalność CNT, a tłumienie długich pęknięć spowodowało zmniejszenie obszaru uszkodzenia.

EN

New nanomaterials for sport equipment were prepd. by reinforcing an epoxy resin (EP) with C fibers (CF) and/or C nanotubes (CNT) to improve quality, hardness, plasticity and aging resistance of the composite materials. The CNT were uniformly dispersed by vacuum filtration and phys. deposition on CF fiber surface. The bending strength of CF/EP-CNT composites was by 28.08% higher than that of an unmodified CF/EP composite. After aging at 120°C, the stress in the composite was dispersed due to the excellent dispersibility of CNT, and the suppression of long cracks resulted in a redn. of damage area.

12

Functionalization methods of carbon fibers – an overview

Magdziarz Sylwia, Frączyk Justyna, Boguń Maciej

Polimery

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2023

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Vol. 68, nr 6

307--316

EN

This article is a literature review related to the methods of functionalization of carbon fibers for tissue engineering applications. Through physical modification, it is possible to obtain a layer of a chemical compound on the carbon fibers surface and to impart additional properties. On the other hand, chemical modification may lead to the incorporation of appropriate functional groups into the carbon fiber structure, capable of attaching, among others, biologically active compounds. The paper presents the advantages and disadvantages of the carbon fibers modifying methods, with particular emphasis on the use of such modified fibers in medicine.

PL

Niniejsza praca stanowi przegląd literatury dotyczący metod funkcjonalizacji włókien węglowych przeznaczonych do zastosowań w inżynierii tkankowej. Poprzez modyfikację fizyczną możliwe jest uzyskanie warstwy związku chemicznego na powierzchni włókien węglowych i nadanie im dodatkowych właściwości. Natomiast modyfikacja chemiczna może prowadzić do wbudowania w strukturę włókna węglowego odpowiednich grup funkcyjnych zdolnych do przyłączania m.in. związków aktywnych biologicznie. W pracy przedstawiono zalety i wady stosowanych metod modyfikacji włókien węglowych, ze szczególnym naciskiem na zastosowanie tak modyfikowanych włókien w medycynie.

13

Electromagnetic interference shielding effectiveness of multi-cracked strain-hardening cementitious composites (SHCC)

Kim Soonho, Jang Yun Sik, Oh Taegeun, Lee Seung Kyun, Yoo Doo-Yeol

Archives of Civil and Mechanical Engineering

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2023

|

Vol. 23, no. 3

art. no. e179, 2023

EN

With the rapid increase in the use of wireless electronic devices, electromagnetic pollution has been recognized as a serious threat. There has been an increasing demand for the use of cement composites as electromagnetic shielding materials. Thus, this study investigated the advantages of adding a small dosage of carbon fibers to enhance the mechanical and electrical properties of strain-hardening cementitious composites (SHCCs) containing steel fibers. In addition, the effect of microcrack formation on the electromagnetic interference (EMI) shielding effectiveness of the SHCCs was analyzed. For this purpose, four different residual tensile strains were applied in preloading tests in the range of 0.015–0.1%. The test results suggested that the tensile performance of the SHCCs was improved by adding 0.2 vol% carbon fibers. Moreover, the rate of increase of the energy absorption capacity was higher (50%) than those of the tensile strength and strain capacity. The electrical conductivity and EMI shielding effectiveness of the SHCCs were noticeably increased by the addition of carbon fibers. The highest shielding effectiveness of 45.6 dB, at 1 GHz, was achieved for the SHCC containing 2% steel fibers and 0.2% carbon fibers, which was approximately 6% higher than that of the corresponding plain SHCC with only steel fibers. An approximately 44–47% lower shielding effectiveness was observed with the formation of through microcracks; however, the number of cracks and the residual tensile strain did not significantly influence the shielding effectiveness. This study can be a basis for evaluating EMI shielding effectiveness of damaged structures.

14

Unconventional Methods of Joining Composites and Metals in the Context of Weight Reduction of Car Bodies

Sabadka Dušan, Kender Štefan

Advances in Science and Technology. Research Journal

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2023

|

Vol. 17, no. 1

230--242

EN

One of the basic trends in the automotive industry today is to achieve the most acceptable ratio between the total weight of the car to its overall performance and utility properties. Reducing the weight of cars is largely due to the use of new materials, where composite materials offer a wide space for their application. Composite materials have their specific properties which is very beneficial in reducing the total weight. Another advantages is strength, stiffness, low fiber density, the ability to form them into any shape based on the required applications. One of the challenges associated with the use of composite materials is the search for new technological possibilities of joining composite materials with metals. These include technologies as for example riveting, ultrasonic welding, but especially gluing. Bonding is currently one of the most preferred ways of joining composite materials. The paper deals with testing of technology of bonding composite materials with metals used in the manufacture of automobiles and a comparison of individual results obtained from the experiment.

15

Hierarchical Carbon Fiber-Carbon Nanotubes by Using Electrospray Deposition Method with Preserved Tensile Properties

Zakaria Muhammad Razlan, Akil Hazizan Md, Omar Mohd Firdaus, Al Bakri Abdullah Mohd Mustafa, Rahim Shayfull Zamree Abd, Nabiałek Marcin, Wysłocki Jerzy J.

Archives of Metallurgy and Materials

|

2022

|

Vol. 67, iss. 4

1299--1304

EN

In this study, the electrospray deposition (ESD) method was used to deposit carbon nanotubes (CNT) onto the surfaces of carbon fibers (CF) in order to produce hybrid carbon fiber-carbon nanotubes (CF-CNT) which is rarely reported in the past. Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), high-resolution transmission electron microscopy (HRTEM) and x-ray photoelectron spectroscopy (XPS) were used to analyse the hybrid carbon fiber-carbon nanotube (CF-CNT). The results demonstrated that CNT was successfully and homogenously distributed on the CF surface. Hybrid CF-CNT was then prepared and compared with CF without CNT deposition in terms of their tensile properties. Statistically, the tensile strength and the tensile modulus of the hybrid CF-CNT were increased by up to 3% and 25%, respectively, as compared to the CF without CNT deposition. The results indicated that the ESD method did not cause any reduction of tensile properties of hybrid CF-CNT. Based on this finding, it can be prominently identified some new and significant information of interest to researchers and industrialists working on CF based products.

16

Electromagnetic wave absorption performance of UHPC incorporated with carbon black and carbon fiber

Xu Shenchun, Yang Yekai, Wu Chengqing, Liu Kai

Archives of Civil and Mechanical Engineering

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2022

|

Vol. 22, no. 2

art. no. e71, 1--17

EN

This study focuses on the electromagnetic wave absorption performance (EWAP) of ultra-high-performance concrete (UHPC) incorporated with carbon black (CB) and carbon fiber (CF) in 2-18 GHz frequency range (required for the radar wave absorbing materials). The reflectivity of the traditional UHPC was investigated and compared to the cement-based composites reported in the literatures, so as to illustrate the advantages of novel UHPCs with respect to EWAP. Afterwards, the effect of CB and CF on the compressive strength, complex permittivity and reflectivity of the novel UHPCs was investigated. The microstructure of the novel UHPCs was also explored via scanning electron microscopy to illustrate the mechanism of performance enhancement on incorporating CB and CF. The results indicated that EWAP of the traditional UHPC was similar or inferior (at specific frequencies) to the literature reported cement-based composites. However, EWAP of the novel UHPCs was significantly improved after reinforcing with CB or CF. A positive effect of CB and CF was also observed on the compressive strength of the developed UHPCs. This study provides avenues for the use of UHPCs in protecting structures for absorbing the electromagnetic waves and safeguarding these structures against extreme loads, including blast and penetration.

17

Strength analysis of a prototype composite helicopter rotor blade spar

Kliza Rafał, Ścisłowski Karol, Siadkowska Ksenia, Padyjasek Jacek, Wendeker Mirosław

Applied Computer Science

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2022

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Vol. 18, no. 1

5--19

EN

This paper investigates the strenght of a conceptual main rotor blade dedicated to an unmanned helicopter. The blade is made of smart materials in order to optimize the efficiency of the aircraft by increasing its aerodynamic performance. This purpose was achieved by performing a series of strength calculations for the blade of a prototype main rotor used in an unmanned helicopter. The calculations were done with the Finite Element Method (FEM) and software like CAE (Computer-Aided Engineering) which uses advanced techniques of computer modeling of load in composite structures. Our analysis included CAD (Computer-Aided Design) modeling the rotor blade, importing the solid model into the CAE software, defining the simulation boundary conditions and performing strength calculations of the blade spar for selected materials used in aviation, i.e. fiberglass and carbon fiber laminate. This paper presents the results and analysis of the numerical calculations.

18

Modeling of high-speed flywheel designs for technological equipment

Dehtiarov Ivan, Antosz Katarzyna, Avramenko Serhiy, Herasko Kostyantyn, Ivanov Vitalii

Technologia i Automatyzacja Montażu

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2021

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nr 2

13--19

PL

W artykule przeanalizowano konstrukcję napędów mechanicznych oraz obszary ich zastosowania. Na podstawie przeprowadzonej analizy opracowano projekt napędu kinetycznego opartego na sprzęgle z materiału kompozytowego, przeznaczonego do pracy z wysoką częstotliwością obrotową. Zaproponowano najbardziej optymalne koła zamachowe pod względem akumulacji energii kinetycznej i jednocześnie maksymalnej wytrzymałości konstrukcji oraz przeprowadzono ich symulację numeryczną. Na podstawie wyników analizy modalnej ustalono wartości i postaci częstotliwości własnych oscylacji wirników ze sprzęgłami o różnych konstrukcjach, co pozwala na sterowanie procesem, znając graniczne wartości maksymalnej dopuszczalnej częstotliwości obrotów. Na podstawie modelowania numerycznego ustalono, że kształt sprzęgła oraz jego masa mają istotny wpływ na ograniczenie prędkości obrotowej. Jednocześnie sprzęgło o najmniejszej masie, ale największej częstotliwości obrotów ma maksymalną jednostkową energochłonność, co świadczy o tym, że jest to najbardziej efektywny wariant pod względem kosztów materiałowych i zastosowania tej konstrukcji w urządzeniach do gromadzenia energii podczas pracy urządzeń technologicznych. Porównano koszt dla sprzęgła o zawartości materiału kompozytowego powyżej 68% z kosztem sprzęgła, które ma maksymalną wartość jednostkową energochłonności na 1 kg masy.

EN

The article analyzes the design of mechanical energy drives and their use areas. Based on the analysis, the kinetic energy drive designis based on the composite material's flywheel, capable of working with a high frequency of rotation. The most optimal flywheels in terms of accumulation of kinetic energy and at the same time the maximum strength of the design are proposed, and their numerical simulation is carried out. The modal analysis results established the values and forms of the eigenfrequencies of oscillations of rotors with flywheels of various structures, which allows controlling the process of overclocking, knowing the limit values of the maximum permissible frequency of rotation of the flywheels. Numerical modeling established that the flywheel's shape and its mass significantly affect the rotor speed limit with the flywheel. At the same time, the flywheel with the lowest mass but the highest frequency of rotation has the maximum specific energy intensity per unit of mass, which determines it as the most effective option in terms of the cost of material and the use of this design in devices for energy accumulation during the operation of technological equip-ment. The calculation results also show that the lamb flywheel has the most incredible absolute energy in-tensity. Simultaneously, the costs of the composite material above 68% are compared with the flywheel, which has the maximum specific value of the energy intensity per 1 kg of its mass.

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Analiza przykładów wykorzystania kompozytów typu CFRP w budowie pojazdów szynowych

Słowiński Marcin

Problemy Kolejnictwa

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2021

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Z. 193

43--51

PL

Celem niniejszego artykułu jest przedstawienie najważniejszych informacji dotyczących kompozytów typu CFRP i przykładów ich zastosowania w budowie pojazdów szynowych. W pierwszej części artykułu przedstawiono podstawowe cechy charakterystyczne kompozytów typu CFRP, a także zaprezentowano porównanie ich właściwości z właściwościami konwencjonalnych materiałów konstrukcyjnych. Następnie omówiono przykłady wykorzystania kompozytów z tej grupy w budowie elementów konstrukcyjnych pojazdów szynowych. Ostatnią część artykułu stanowi analiza motywacji, które przemawiają za wprowadzeniem tego rodzaju kompozytów do inżynierskiej praktyki kolejowej.

20

An Analysis of CFRP Application in the Construction of Rail Vehicles

Słowiński Marcin

Problemy Kolejnictwa

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2021

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Z. 193

105--113

EN

The aim of this article is to provide crucial information on CFRP composites and examples of their use in rail vehicle construction. The first part outlines the key characteristics of CFRP composites and compares their properties with conventional structural materials. Implementation examples of this group of composites for structural components of rail vehicles are discussed further. The final section of the article analyses the reasons for introducing composites of this type into the engineering practice of railways.