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1

Ekologiczne opakowania z nadrukiem na podłożu metalizowanym

Khadzhynova Svitlana, Płatek Andrzej, Frąc Anna

Przegląd Papierniczy

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2023

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R. 79, nr 6

334--340

PL

W ramach badań została opracowana technologia produkcji opakowań tekturowych z wierzchnią warstwą uzyskaną metodą metalizacji pośredniej z zastosowaniem folii transferowej. Zbadano właściwości laminatów oraz opakowań z laminatów z folią transferową i porównano je z właściwościami laminatów i opakowań z użyciem folii tradycyjnej. Opakowania wykonane z tektury z warstwą metalizowaną z folii transferowej charakteryzowały się zbliżonymi parametrami mechanicznymi oraz podobną jakością nadruku oraz niektórymi innymi parametrami do opakowań z warstwą metalizowaną z folii tradycyjnej. Jednakże są one bardziej przyjazne dla środowiska – nadają się do recyklingu i charakteryzują się mniejszym śladem węglowym.

EN

As part of the research, the technology for the production of board packaging with a metallized top layer obtained by indirect metallization with the use of transfer foil was developed. The properties of laminates and packaging from these laminates with transfer foil were tested and compared with the properties of laminates and packaging with traditional foil. Packaging made of board with a metallized layer from transfer foil was characterized by similar mechanical parameters and similar print quality and some other parameters as packaging with a metallised layer based on traditional foil, but they were more environmentally friendly: they are recyclable, are characterized by less environmental impact and a smaller carbon footprint.

2

An experimental investigation of fracture modes and delamination behaviour of carbon fiber reinforced laminated composite materials

Musafir Mustafa Abd Alhussein, Ameer Zuhair Jabbar Abdul, Hamzah Ahmed Fadhil

Diagnostyka

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2023

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Vol. 24, No. 1

art. no. 2023101

EN

Mechanically, composite laminates perform exceptionally well in-plane but poorly out-of-plane. Interlaminar damage, known as "delamination," is a major issue for composite laminates. Results from Mode-I and Mode-II experimental testing on twill-woven carbon fiber reinforced (CFRP) laminates are analyzed in this paper. Composite Mode-I fracture toughness was determined using three different methods in accordance with ASTM D5528: modified beam theory, compliance calibration, and a codified compliance calibration. Two methods, the Compliance Calibration Method and the Compliance-Based Beam Method, were used to determine the Mode-II fracture toughness in accordance with ASTM D7905. Stick-slip behavior is quite evident in the composite's ModeI fracture toughness test findings. The MBT technique's 𝐺Ic values for initiation and propagation are 0.533 and 0.679 KJ/m2 , respectively. When comparing the MBT approach to the industry-standard ASTM procedure for determining fracture toughness Mode-I, the MBT method was shown to be highly compatible. Furthermore, the 𝐺IIc values for the CBBM technique are 1.65 KJ/m2 for non-pre cracked and 1.4 KJ/m2 for pre-cracked materials. The CBBM method shows a good method to evaluate fracture toughness Mode-II, due to not needing to monitor the length of the crack during delamination growth to get the value of the fracture toughness.

3

Diagnostyka przedwczesnych uszkodzeń betonowych posadzek przemysłowych utwardzanych powierzchniowo

Glinicki Michał A., Jóźwiak-Niedźwiedzka Daria, Brandt Andrzej M.

Cement Wapno Beton

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2023

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R. 28, nr 6

409--427

PL

W artykule przedstawiono wyniki badań diagnostycznych betonowych posadzek przemysłowych utwardzanych powierzchniowo. Wybrane przykłady posadzek obejmowały przedwczesne uszkodzenia warstw powierzchniowych, wykazujących intensywne pylenie, miejscowe delaminacje i obszarowe odpryski, bez uszkodzeń układu konstrukcyjnego. Zastosowano technikę ilościowych badań petrograficznych betonu na próbkach-odwiertach z posadzek, obejmujących analizę cyfrowych obrazów mikroskopowych z mikroskopu optycznego polaryzacyjnego i mikroskopu skaningowego. Posypkę utwardzającą i sproszkowane próbki matrycy cementowej badano za pomocą termicznej analizy różnicowej i dyfraktometrii rentgenowskiej. Metodę badania mikrotwardości wykorzystano do oceny miejscowego zróżnicowania właściwości mechanicznych. W przekrojach betonu zidentyfikowano obszary niejednorodności rozkładu porów powietrznych, zlokalizowano obszary o podwyższonej porowatości i obszary spękań w betonie, oznaczono lokalną zmienność składu fazowego produktów hydratacji cementu oraz występowanie obszarów skarbonatyzowanych. Na tej podstawie przedyskutowano przyczyny powstania uszkodzeń. Wykazano kluczową rolę ilościowych badań petrograficznych w diagnozowaniu przedwczesnych powierzchniowych uszkodzeń posadzek przemysłowych.

EN

The article presents the diagnostic results on surface-hardened industrial concrete floors. Selected examples of floors showcased premature damage to surface layers, characterized by intense dusting, delamination, and local spalling, while the structural system remained unaffected. Quantitative petrographic analysis of concrete was applied to core specimens from the floors, involving the examination of digital images from a polarizing optical microscope and a scanning electron microscope. The hardening compound and powdered specimens of the cement matrix were characterized using differential thermal analysis and X-ray diffraction. A multiple microindentation method was employed to assess local variations in mechanical properties. Concrete cross-section analysis revealed areas with a non-uniform distribution of air voids, identified regions exhibiting increased porosity, highlighted areas of cracking in the concrete, indicated local variability in the phase composition of cement hydration products, and pointed out the presence of carbonated areas. The causes of the damage were discussed based on these findings. The crucial role of quantitative petrographic analysis in diagnosing premature surface damage to industrial floors was demonstrated.

4

Badania nieniszczące materiałów kompozytowych metodą termografii laserowej

Hyla Bartosz, Sobczak Michał, Roemer Jakub

Badania Nieniszczące i Diagnostyka

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2023

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nr 1-4

62--66

PL

Termografia jest jedną z metod badań nieniszczących, która wykorzystuje termowizję do wnioskowania o stanie technicznym materiału. Termografia laserowa jest rodzajem termografii aktywnej w której źródłem wymuszenia jest promieniowanie laserowe. Metoda ta pozwala na bardzo precyzyjne kontrolowanie ilości energii dostarczanej do próbki. Istotną zaletą w badaniach laserowych jest możliwość wykrywania zarówno delaminacji jak i pęknięć będącymi głównymi rodzajami uszkodzeń strukturach kompozytowych. W pracy przedstawione zostanie stanowisko do badań, którego prototyp jest opracowywany na AGH oraz wyniki skanowania na przykładzie próbki z włókna węglowego w osnowie polimerowej.

EN

Thermography is a non-destructive testing method that utilizes infrared camera to infer the technical condition of a material. Laser thermography is a type of active thermography in which laser radiation serves as the excitation source. This method allows for highly precise control of the amount of energy delivered to the sample. An important advantage of laser testing is the capability to detect both delamination and cracks, which are the main types of damage in composite structures. This paper presents a test setup developed at AGH University of Krakow and the results of scanning a sample made of carbon fiber reinforced polymer.

5

Influence of drill bit material on the bearing strength of holes in GFRP composite

Galińska Anna

Archive of Mechanical Engineering

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2023

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LXX, nr 2

287--310

EN

The article aims at assessing the influence of the drill bit material on the bearing strength of holes made in glass fabric reinforced epoxy composite. Six twists made of widely used drill materials such as high speed steels and carbides in different configurations were selected to drill holes in the composite. In the first stage of the work, optimum drilling parameters were selected and then used for drilling holes in specimens tested in single lap shear experiments. For each tested specimen two different delamination factors, one based on the delamination area and another - on its diameter, were calculated in order to assess the quality of the holes and then compared to the results of the bearing strength experiments. The results of the bearing tests showed that the highest strength was achieved for the high speed steel drill with titanium coating while the lowest for the cemented carbide drill. This finding is in opposition to the majority of results reported in literature.

6

Efficacy comparison of two methods for determining the position of the rebate edge (formed after MDF machining) during automatic monitoring of workpiece delamination

Śmietańska Katarzyna, Górski Jarosław

Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology

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2023

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No. 123

60--65

EN

Efficacy comparison of two methods for determining the position of the rebate edge (formed after machining) during automatic monitoring of workpiece delamination. Delamination is one of the most common defects in the processing of wood-based materials. It has a huge impact on the quality of the final product. In order to determine the delamination indicators in a simple and reliable way, the automatic image processing method can be used (Śmietańska et al. 2020). Bator and Śmietańska (2019) proposed the special algorithm to estimate the straight line representing a milling edge. However, this algorithm is quite complicated. The aim of this article is to check whether the aforementioned (complicated) algorithmic way can be replaced by a much simpler idea – the precise manual positioning of the scanned sample on the scanner (using very simple device installed on the scanner). The special experimental research was carried out to compare the effectiveness of the two different methods. The straight line which represents the rebate edge identified by Bator and Śmietańska (2019) algorithm was usually accurate to 1 pixel (0.02 mm). The analogue line based on the assumption that the scanned samples were perfectly positioned on the scanner only sometimes fit just as well. At worst, the distance between these lines is 0.2 mm. Usually the distance did not exceed 0.16 mm but was significant and quite random. There was no statistically significant correlation between this parameter (Dmax) and tool condition (VB). It means that sample were not perfect positioned. They were placed more or less in the same position because of imperfect stiffness of the frame installed on the scanner and human errors.

PL

Porównanie efektywności dwóch metod wyznaczania położenia krawędzi wręgu (powstałego po frezowaniu MDF) podczas automatycznej oceny delaminacji przedmiotu obrabianego. Delaminacja jest jedną z najczęściej występujących wad powstałych w wyniku obróbki skrawaniem materiałów drewnopochodnych. Stan krawędzi jest niezwykle ważnym kryterium oceny jakości wyrobu finalnego. W celu prostego i rzetelnego określenia wskaźnika delaminacji doskonałym rozwiązaniem wydaje się zastosowanie metody automatycznego przetwarzania obrazu (Śmietańska i in.2020). Bator i Śmietańska (2019) zaproponowali specjalny, jednak dość skomplikowany, algorytm pozwalający na estymację prostej reprezentującej krawędź wręgu powstałego w procesie frezowania. Celem artykułu jest sprawdzenie, czy powyższą metodę (z zastosowaniem algorytmu) można zastąpić znacznie prostszym rozwiązaniem - precyzyjnym ręcznym pozycjonowaniem skanowanej próbki na skanerze (przy pomocy specjalnego nieskomplikowanego przyrządu). Aby porównać skuteczność dwóch metody przeprowadzono badania eksperymentalne. Linia prosta reprezentująca krawędź wręgu oszacowana z zastosowaniem algorytmu Batora i Śmietańskiej (2019) osiągała przeważnie dokładność 1 piksela (0,02mm). W przypadku linii analogowej opartej na założeniu, że zeskanowane próbki były idealnie umiejscowione na skanerze zaobserwowano znacznie mniejszą dokładność. W najgorszym przypadku różnica pomiędzy liniami wynosiła 0,2 mm (zwykle nie przekraczała 0,16 mm). Nie zaobserwowano także istotnej statystycznie korelacji między parametrem Dmax, a stopniem zużycia narzędzia VB. Ręczna metoda okazała się zdecydowanie mniej precyzyjna. Za przyczynę tego można uznać niewystarczającą sztywność przyrządu do pozycjonowania próbki na skanerze oraz błędy ludzkie.

7

Numerical Modelling and Experimental Testing on Polyurethane Adhesively Bonded Joints Behaviour in Wood-Wood and Wood-Carbon Fibre Reinforced Polymer Layouts

Kawecki Bartosz

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 2

36--52

EN

Scientists do a variety of laboratory tests on timber and wood-containing composites. An example is adhesively bonded joints in such materials. Despite a wide range of empirical research, consideration of adhesive layers or surfaces in a structure is commonly done in a very simplified manner - they are often modelled as a perfect connection between adherends. It means the cohesive stiffness and opportunity of progressive delamination are neglected. This may lead to an overestimation of the structural load-bearing capacity. The article presents wood-wood and wood-CFRP adhesively bonded joints’ investigations, based on own experimental testing technique (covering a current one as a Digital Image Correlation), analytical double-lap model for adhesives and advanced numerical Finite Element approach. The aim of the paper is to give the guidelines for complex, non-linear modelling of connections in glue laminated timber and wood-CFRP composites that can be utilised for many purposes.

8

Influence of montmorillonite hydration and delamination on coal flotation

Zhang Lucheng, Zhang Mingqing, Liu Qi, Song Shuoshuo, Tian Yu, Barvora Joshua Bosco

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 153085

EN

In this study, the influence of montmorillonite (MT) hydration and delamination on coal flotation was investigated through flotation tests using coal-MT mixtures. MT particles were subjected to hydration at different time intervals. The Fuerstenau upgrading curve was plotted to evaluate the change in overall flotation selectivity. The zeta potential and particle size distribution were used to characterize the delamination behavior of MT in deionized water at natural pH level. Atomic force microscopy (AFM) (colloidal probe) was used to analyze the interaction force between coal and MT particles. It was found that smaller particles (individual silicate layers or thin packets of layers) with higher zeta potentials appeared gradually, and their volume proportion increased with increasing hydration time. AFM results showed that a monotonous repulsive force was detected consistently throughout the separation distance between coal and these emerging smaller MT particles. The decrease of these MT coating on coal surface was responsible for the higher flotation recovery and better selectivity. A jump-into-contact phenomenon was observed in coal and MT interaction when MT hydrated incompletely. It showed that heterocoagulation between coal and MT occurred and MT coating on the coal surface was responsible for the depression of flotation.

9

Multi-layered non-linear viscoelastic beams subjected to torsion at a constant speed: a delamination analysis

Rizov Victor Iliev, Altenbach Holm

Engineering Transactions

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2022

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Vol. 70, iss. 1

53--66

EN

A non-linear mechanical model with a linear spring, a linear dashpot and a non-linear dashpot is used for studying the non-linear viscoelastic behaviour of a multi-layered inhomogeneous beam with a delamination crack. The beam with a circular cross-section is under a torsion moment that increases at a constant speed. The non-linear stress-strain-time constitutive law of the model is obtained by adding the non-linear shear strain to the strain in the linear spring and linear dashpot. Solutions of the time-dependent strain energy release rate are derived, which take into account the non-linear viscoelastic behaviour of the beam and the torsion moment rate.

10

Simulation of the effect laminate sequence on delamination mode-I with elastic couplings

Alhussein Mustafa Abd, Ameer Zuhair Abdul, Hamzah Ahmed Fadhil

Diagnostyka

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2022

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Vol. 23, No. 2

no. art. 2022211

EN

A numerical study using the ANSYS 19.R3 environment is discussed in this research. This environment depends on the Virtual Crack Closure Technique (VCCT) method to test a double cantilever beam (DCB) according to the ASTM D5528 standard. Four kinds of laminate stacking sequences were considered. According to the results, the distribution of the strain energy release rates obtained along the delamination front in bending-extension and extension-twisting coupling had a good affinity with bending-extension coupling. At the same time, critical fracture toughness values were estimated to be around 87.9% of critical fracture toughness values bending-extension coupling. These results are proof of the bending-extension and extensiontwisting coupling success while testing the proximity to bending-extension coupling results of the DCB beam. These findings are compatible with the standard ASTM D5288. Therefore, the bending-extension and extension-twisting coupling provide a good indication of the delamination resistance during buckling tests of the composite.

11

Formulating delamination-fretting wear failure predictive equation in HAp coated hip arthroplasty using multiple linear regression model

Nagentrau M., Ibrahim N.H., Jamian S., Mohd Tobi A.L.

Archives of Materials Science and Engineering

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2022

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Vol. 115, nr 2

76--85

EN

Purpose: Present paper addresses the formulation of delamination-fretting wear failure predictive equation in HAp-Ti-6Al-4V interface of hip arthroplasty femoral stem component using multiple linear regression model. Design/methodology/approach: A finite element computational model utilising adaptive meshing algorithm via ABAQUS/Standard user subroutine UMESHMOTION is developed. The developed FE model is employed to examine effect of different HAp-Ti-6Al-4V interface mechanical and tribological properties on delamination-fretting wear behaviour. The FE result is utilised to formulate predictive equations for different stress ratio conditions using multiple linear regression analysis. Findings: Delamination-fretting wear predictive equations are successfully formulated with significant goodness of fit and reliability as a fast failure prediction tool in HAp coated hip arthroplasty. The robustness of predictive equations is validated as good agreement is noted with actual delamination-fretting wear results. Research limitations/implications: The influence of different mechanical and tribological properties such as delamination length, normal loading, fatigue loading, bone elastic modulus and cycle number under different stress ratio on delamination-fretting wear failure is analysed to formulate failure predictive equations. Practical implications: The formulated predictive equation can serve as a fast delamination-fretting wear failure prediction tool in hip arthroplasty femoral stem component. Originality/value: Limited attempt is done to explore the potential of utilizing multiple linear regression model to predict failures in hip arthroplasty. Thus, present study attempt to formulate delamination-fretting wear failure predictive equation in HAp -Ti-6Al-4V interface of hip arthroplasty femoral stem component using multiple linear regression model.

12

Measurement and evaluation of delamination factors and thrust force generation during drilling of multiwall carbon nanotube (MWCNT) modified polymer laminates

Kumar Kuldeep, Verma Rajesh Kumar

Archive of Mechanical Engineering

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2022

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LXIX, nr 2

269--300

EN

In recent years, manufacturing industries have demanded high-performance materials for structural components development due to their reduced weight, improved strength, corrosion, and moisture resistance. The outstanding performance of polymer nano-composites substitutes the use of conventional composites materials. This study is concerned with the machining of MWCNT and glass fiber-modified epoxy com posites prepared by a cost-effective hand layup procedure. The investigations were carried out to estimate the generation of the thrust force (Th) and delamination factors at entry (DFentry) and exit (DFexit) side during the drilling of fiber composites. The effect of varying constraints on the machining indices was explored for obtaining an adequate quality of hole created in the epoxy nano-composites. The outcome shows that the feed rate (F) is the most critical factor influencing delamination at both entry and exit side, and the second one is the thrust force followed by wt.% of MWCNT. The statistical study shows that optimal combination of S (1650 Level-2), F (165 Level-2), and 2 wt.% of MWCNT (Level-2) can be used to minimize DFentry, DFexit, and Th. The drilling-induced damages were studied by means of a high-resolution microscopy test. The results reveal that the supplement of MWCNT substantially increases the machining efficiency of the developed nano-composites.

13

Stability and failure of thin-walled composite structures with a square cross-section

Czajka Błażej, Różyło Patryk, Dębski Hubert

Applied Computer Science

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2022

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Vol. 18, no 2

43--55

EN

This paper is devoted to the analysis of the stability and load-carrying capacity of thin-walled composite profiles in compression. The specimens reflect elements made of carbon fibre reinforced laminate (CFRP). Thin-walled columns with a square cross-section were made from 4 layers of composite in 3 different combinations of layer arrangements. Advanced numerical analyses have been carried out. In the first stage of the study, a buckling analysis of the structure was performed. In further numerical simulations, two advanced models were used simultaneously: the Progressive Failure Analysis (PFA) and the Cohesive Zone Model (CZM). The results showed significant differences between the critical load values for each layer configuration. The forms of buckling and the areas of damage initiation and evolution were also dependent on the applied layup.

14

A Study on Mechanical Strength and Failure of Fabric Reinforced Polymer Composites

Korzec Izabela, Samborski Sylwester, Łusiak Tomasz

Advances in Science and Technology. Research Journal

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2022

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Vol. 16, no 2

120--130

EN

The paper presents a study on influence of different fabric weave and fabric orientation on strength properties of fiber reinforced polymer composites. The research concerns materials used in a new type of rotorcraft. Four series of laminates were fabricated with hand forming, using the MGS L285/H285 epoxy resin. Triple-kind experiments were performed: the Shore hardness measurements, tensile strength testing and fractographic analysis. The specimens of different series shown various strength and stiffness characteristics, depending on the type of weave and fabric layup. Three different failure schemes were observed. The Poisson coefficient was different among series, as well, but no understandable link to specimen morphology could be found so far. Fractographic observations suggested intralaminar delamination.

15

Coupled circuit method applied to the detection of defects in a conductive multilayer device

Bouali Ferroudja, Mohellebi Hassane, Yousfi Ghania

Przegląd Elektrotechniczny

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2021

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R. 97, nr 3

106--112

EN

The work present the coupled circuit method applied to an eddy current nondestructive testing (EC-NDT) problems. The device is consisting on a conductive multilayer structure having an air gap (delamination), or a physical defect (lack of material). The purpose of the study is to identify the presence of the delamination when a physical defect can occur simultaneously. The use of Coupled Circuits Method permits to reduce the discretization to only the active parts without mesh air gap. The results obtained are compared to finite elements ones. A good agreement is observed between results. Interesting and useful conclusions are made.

PL

W pracy przedstawiono metodę obwodów sprzężonych zastosowaną do badań nieniszczących prądów wirowych (EC-NDT). Urządzenie składa się z przewodzącej konstrukcji ze szczeliną powietrzną (rozwarstwieniem) lub wadą fizyczną (brak materiału). Celem badania jest identyfikacja obecności rozwarstwienia, gdy jednocześnie może wystąpić wada fizyczna. Zastosowanie metody obwodów sprzężonych pozwala zredukować dyskretyzację tylko do aktywnych części bez siatkowej szczeliny powietrznej. Uzyskane wyniki porównuje się z wynikami elementów skończonych. Obserwuje się dobrą zgodność wyników.

16

Problem delaminacji w posadzkach betonowych

Bajorek Grzegorz, Barć Maciej, Słonina Sławomir, Warchoł Sabina

Materiały Budowlane

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2021

|

nr 10

11--12

17

Discrete wavelet transformation as a tool for analysing the borehole quality when drilling Carbon Fibre Reinforced Plastic aluminium stack material

Duntschew Jonas, Eschelbacher Sarah, Schluchter Ivo, Möhring Hans-Christian

Journal of Machine Engineering

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2021

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Vol. 21, No. 1

78--88

EN

To meet the higher demands of the lightweight industry, composite materials are used for weight-bearing structures. Due to their superior properties, CFRP (Carbon Fibre Reinforced Plastic) – aluminium stacks are especially attractive for many applications in the aerospace industry. Using rivets to connect these materials requires precise boreholes in large numbers, which are usually drilled. Because of the anisotropic material properties, high demands on the tool performance and process stability are set. Damages such as delamination, fibre pull-outs and inadequate surface properties are frequently observed at the drilled boreholes. To improve the monitoring status and failure detection, acoustic emission during drilling was analysed using the discrete wavelet transform method. By converting time signals into multiple independent time-frequency signals, temporary events during the monitoring of the cutting processes can be found. The studies show that certain combinations of wavelet families are particularly useful for describing correlations between acoustic emission and the delamination of the CFRP surface.

18

Durability Assessment of Composite Structural Element Reinforced with Fabric due to Delamination

Marszałek Jerzy, Stadnicki Jacek

Autex Research Journal

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2021

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Vol. 21, no. 3

333--340

EN

Layer composites reinforced with fabrics – laminates are construction materials in which mechanical properties can be shaped by designing their microstructure appropriately. However, the multi-phase microstructure of laminates makes it difficult to calculate the strength of the laminate constructions, especially when the reinforcement is a fabric. The article presents a special calculation model for determining the strength of an exemplary construction element made of laminate reinforced with a roving fabric with a plain weave made of carbon fibers. The computational model reflected in a simplified way the laminate microstructure, i.e. the number and orientation of the reinforcement fabric layers and its weave, and enabled a simulation of the behavior of the construction element under load up to fracture, which occurred as a result of breaking the reinforcement and interlayer crack – delamination. The simulation results were compared with the results of experimental stand tests. A method of modifying the computational model for laminates reinforced with non-plain weave was also suggested.

19

Effect of Composite Material Fixing on Hole Accuracy and Defects During Drilling

Ciecieląg Krzysztof

Advances in Science and Technology. Research Journal

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2021

|

Vol. 15, no 3

54--65

EN

This study investigates the effect of composite material stiffness on the accuracy of drilled holes and delamination in the drilling process. Two types of composite materials were tested: glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP). The drilling process was performed using dedicated drill bits. Samples were clamped in a vice of the Avia-VMC 800 HS vertical machining center. Drilling parameters were maintained constant but unsupported element length was changed. The unsupported element length was defined as an unsupported distance between the drilled hole axis and the sample attachment location. The maximum feed force Ff was determined in the experiments. The accuracy of drilled holes was estimated by optical microscopy. Diameters of the drilled holes were measured. Results made it possible to determine the recommended unsupported element length at which the hole dimensions were within the dimensional tolerance. The study showed a clear decrease in the drilled hole quality and a significant increase in the feed force, especially in the area of tool exit from the workpiece. In addition, the number of delaminated fibers increased with unsupported element length was determined in the study.

20

Wiertło do materiałów kompozytowych redukujące zadziory i delaminację

Jemielniak Krzysztof

Mechanik

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2020

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R. 93, nr 3

34-35

PL

Podczas wiercenia materiałów kompozytowych, takich jak tworzywa sztuczne wzmacniane włóknem węglowym (CFRP), dochodzi do delaminacji oraz powstawania zadziorów na wejściu wiertła w otwór i jego wyjściu z otworu. W artykule zaproponowano projekt wiertła, które mogłoby ograniczyć te niekorzystne zjawiska.