COMPOSITES THEORY AND PRACTICE

Research Journal of The Polish Society of Composite Materials

Editorial Board

Editor-in-Chief

Katarzyna N. Braszczyńska-Malik (Poland): Czestochowa University of Technology, Faculty of Production Engineering and Materials Technology, Institute of Materials Engineering, Poland
Metal matrix composites, light metal alloys, fabrication processes, microstructure and properties

Associate Editors



Jan Dusza (Slovakia): Institute of Materials Research, Slovak Academy of Sciences, Slovak Republic
Microstructure and mechanical properties of ceramic matrix composites, nano-composites, fractographic failure analysis of brittle materials, nano-mechanical testing of advanced ceramic and ceramic based composites
Jerzy Sobczak (Poland): Foundry Research Institute, Poland
Metal matrix composites, lightweight metals and alloys, functionally graded structures, high porosity media, special foundry techniques
Abdullach Tugrul Seyhan (Turkey): Eskisehir Technical University (ETU), Faculty of Engineering, Department of Materials Science and Engineering, Turkey
Nanocomposites, processing of fibre reinforced polymer composite materials, mechanical, thermal, physical and microstructural characterization of composite materials
Mateusz Kozioł (Poland): Silesian University of Technology
Polymer matrix composites (PMCs), functional nanocomposites, recycling of PMCs

Editorial Board







Victor Birman (USA)
Stanisław Błażewicz (Poland)
Aldo R. Boccaccini (United Kingdom)
T.W. Clyne (United Kingdom)
Philippe Colomban (France)
Ignazio Crivelli-Visconti (Italy)
Lech Czarnecki (Poland)
Jan Dutkiewicz (Poland)
Luciano Feo (Italy)
Ludo Froyen (Belgium)
Werner Hufenbach (Germany)
David Hui (USA)
Karl U. Kainer (Germany)
Jang-Kyo Kim (Hong Kong, China)
Marian Klasztorny (Poland)
Józef Koszkul (Poland)
Lothar Kroll (Germany)
Satish Kumar (USA)
Krzysztof J. Kurzydłowski (Poland)
Marcin Leonowicz (Poland)
Pavel Lukac (Czech Republic)
Gad Marom (Israel)
Stanisław Mazurkiewicz (Poland)
Roger Naslain (France)
Seeram Ramakrishna (Singapore)
Michał Szweycer (Poland)
Akira Todoroki (Japan)
Danuta Żuchowska (Poland)

Aims and Scope:

The Composites Theory and Practice Journal constitutes a medium for the publication of theoretical and experimental studies and reviews on fabrication techniques, structure, properties, behaviour and engineering applications of a wide range of composite materials. The Journal publishes original (research and technological) manuscripts and, occasionally, reviews on all aspects of composite materials science and technology.

The main topics covered by the journal are:

Composite materials

Polymer matrix composites (PMCs)
Ceramic matrix composites (CMCs)
Metal matrix composites (MMCs)
Bio-composites
Nano-composites
Smart composites

Production technologies of composites and their processing
Materials science and engineering of composite materials
1. Macro- and microstructure
2. Reaction and interfaces between components
3. Correlation between structure and properties
4. Mechanical, thermal, electrical, magnetic, optical, acoustic, other physical and chemical properties, corrosion and tribology
5. Biocompatibility
Mechanics of composite materials from nano to macro scales
1. Identification of mechanical (static and dynamic) and physical properties
2. Constitutive models
3. Strain rate and temperature sensitive mechanical properties
4. Rheology of composite materials
5. Degradation, damage, fracture, failure
6. Random properties, durability and reliability of composite materials and structures
Numerical modelling, simulation, validation and verification of composite materials and structures (statics, stability, dynamics, rheology)
1. Application of FE codes to modelling and simulation
2. Experimental validation and verification of numerical modelling and simulation
3. Modelling, simulation, validation and verification of degradation and failure of composite materials and structures and composite joints
4. Optimization of composite materials and structures
Engineering applications of composite materials in civil, mechanical and aerospace engineering, medicine, chemical engineering, marine, automotive and in rail-vehicle engineering
Recycling of composite materials and structures
Health monitoring, degradation, utilization of composite materials and structures
Frontier research and development of composite materials and structures

Other

COMPOSITES THEORY AND PRACTICE Journal Procedures

The Editors accept papers throughout the calendar year. All papers submitted to the Journal are subjected to a thorough peer reviewing process. The prerequisites for accepting articles for publication is to prepare the work in accordance with the requirements of the Journal and to obtain positive reviews.

Before submitting a paper, an Author must prepare it according to the Guidelines for Authors.
After logging into the system, an Author must attach:

his / her details (name and surname, affiliation and current e-mail address)
paper title
paper in Word format
paper in PDF format
become familiar with the provisions regarding ethics in publishing. By submitting an article to the journal, Authors automatically declare that the work is consistent with the principles against ghostwriting, guest authorship and plagiarism.

Each paper submitted to the Journal is subject to preliminary verification by the Editors for compliance with the Journal requirements (the topic and correct preparation of the paper according to the Guidelines for Authors). If the paper does not satisfy the basic requirements, the Author will be requested to revise the paper and resubmit it.

Having met the preliminary conditions, each manuscript is subject to identical procedures:

I. REVIEW PROCEDURE

* All the papers (in PDF format) are sent to Reviewers. The Journal Reviewers are specialists in composite materials, materials engineering and related sciences (Reviewers are always selected from other institutions than the Authors of the paper).The decision to appoint a reviewer belongs only to the Editor.

The reviewers for particular papers are appointed by the Editor-in-Chief (himself or having sought the opinion of the Section Editors) depending on the detailed topic of the submitted paper. Each Reviewer is asked to prepare an opinion on the paper on the standard Review form (available for Reviewers online in electronic format).

Reviewer before commencing work should become familiar with and act in accordance with the principles of ethics for the Journal. The Reviewer must guarantee:

an objective opinion
no conflict of interests (no personal or professional relationships with the paper Authors)
confidentiality.

* The Reviewer can present his / her comments in a descriptive form and classifies the paper as: accepted in the present form, in need of minor revision, in need of major revision or rejected. The Reviewer also has the right to request the paper to be submitted to him / her again after revisions for repeated review and acceptance.

* The Author (or Co-author – named as the contact person to receive correspondence) receives reviews (without the Reviewers’ names) in PDF format.

Where a revision is required, the authors are required to respond in detail to the Editor's, Editorial Office's and Reviewer's comments (by sending to the Editor) and to make corrections to the manuscript. In cases of dispute (including possible rejection of the manuscript) or at the author's request, the decision is taken by the Editors (with the final decision belonging to the Editor-in-Chief), who can appoint further reviewers if necessary.

* If the review is positive or the paper is submitted after corrections according to the Reviewers’ and Editor's remarks, the paper is referred to a further editorial procedure.

II. EDITORIAL PROCEDURE

* Each paper is proofread by a specialist native speaker of English. After proofreading the Author receives the corrected paper for acceptance of the corrections, remarks and suggestions of the proofreader.

* After the language proofreading and acceptance thereof by the Author, technical proofreading is done by the technical proofreader, then the text is typeset and formatted and all the papers submitted to the particular issue are subject to final technical proofreading.

(In case of any doubt arising during technical proofreading or typesetting and formatting of a particular paper, the Coordinating Editor contacts the Author again).

* Finally the whole issue goes to press and after its publication the particular papers are made available online (in PDF format) on the Journal website.

The order in which the papers are printed in the particular issue / publishing year depends both on the date of submission to the Editors and on how fast the paper undergoes the whole procedure as described above.

Submitting an article to the Journal is tantamount to expressing consent to publication in both paper and electronic form. The corresponding Author of the article receives (free of charge) the printed version of the Journal Issue, in which the article appeared. The electronic version is available without restrictions (free of charge to all readers).

By submitting the manuscript, the Authors automatically agree to the processing of the personal data provided by the Editors and Publishing House.

No honorarium will be paid. The journal does not have article submission charges.

The ethics rules

The ethics rules for the Composites Theory and Practice journal are based on the Best Practice Guidelines for Journal Editors issued by the Committee for Publishing Ethics (COPE).

Editors

An editor of a reviewed journal is responsible for making decisions which articles should be published, and in addition be responsible for all publications in the journal. By making these decisions, an editor may be guided by the editorial policy of the journal, as well as the legal requirements for libel, copyright infringement and plagiarism. An editor may communicate with other editors or reviewers when making a decision about publication.
An editor should evaluate manuscripts for intellectual content and follow the COPE guidelines for withdrawing articles. The editor shall not disclose any information about the manuscript he considers to anyone except the authors, reviewers and potential reviewers, and in some cases - members of the editorial board, as deemed appropriate.
Unpublished materials contained in the submitted manuscript cannot be used in the editor's own research. Valuable information or ideas obtained as a result of evaluation of the work must be confidential and cannot be used for personal gain.
The editor undertakes to ensure that advertising, reprinting or other commercial revenues do not affect editorial decisions. The editor should strive to ensure a fair and proper review process. The editor should require all colleagues to disclose relevant conflicting interests.

Reviewers

Reviewing helps the editor in making editorial decisions, and through editorial communication with the author, can also help the author improve the manuscript.
Any invited reviewer who does not feel competent to review the research reported in the article or knows that its timely execution will be impossible, should immediately notify the editor so that alternative reviewers can be contacted.
All manuscripts received for review must be treated as confidential documents. They must not be shown or discussed with other people unless permitted by the editor.
Reviews should be processed objectively. Personal criticism of the author is unacceptable. Reviewers should clearly express their views using appropriate supporting arguments.
The reviewer should also draw the Editor's attention to any significant similarities or overlaps between the manuscripts under consideration and any other published data about which he has personal knowledge.
Privileged information or ideas obtained as a result of the assessment must be confidential and cannot be used for personal gain. Reviewers should not judge manuscripts in the event of a conflict of interest, including those resulting from competitive cooperation or other relationships or connections with any of the authors, a company or institution related to the manuscript.

Authors

Authors reporting the results of original research should provide a detailed description of the performed work and an objective discussion about its significance. Fraudulent or knowingly inaccurate statements constitute unethical behavior and are unacceptable.
Authors should ensure that they have written entirely original works and if they have used the work and/or words of other people, that they have been quoted appropriately.
The author should not publish manuscripts describing basically the same research in more than one journal or original publication. Parallel submission of the same manuscript to more than one journal is considered as unethical publication behavior and is unacceptable.
Proper recognition of the work of others must always be granted. The authors should also cite publications that influenced the inspiration and determined the nature of the submitted work.
Authorship should be limited to persons who have made a significant contribution to the concept, design, performance or interpretation of the results of the submitted manuscript. All those who have made a significant contribution should be listed as co-authors. If there are other people who have participated in certain aspects of the research project, they should be listed in the Acknowledgments section.
The author for correspondence should ensure that all the relevant co-authors (as defined above) are listed and no inappropriate co-authors are included in the list of authors of the manuscript. He/she must also ensure that all the co-authors approved the final version of the article and agreed to submit it for publication.
All authors should disclose in their manuscripts all financial or other conflicts of interest that can be interpreted as affecting the results or their interpretation in the manuscript. All sources of financial support for work should be indicated.
When the author discovers a significant error or inaccuracy in his own published work, it is the responsibility of the author to immediately notify the editor or publisher of the journal and to cooperate to withdraw the article or to publish an appropriate errata.

Publisher confirmation

In cases of alleged or proven scientific abuse, fraudulent publication or plagiarism, the publisher, in close cooperation with the editors, will take all appropriate measures to clarify the situation and change the article. This includes a quick errata publication or, in the most severe cases, complete withdrawal of the paper.

Bibliographical information

Scientific Journal of the Polish Society of Composite Materials

ISSN (Print): 2084-6096

ISSN (Electronic): 2299-128X

Published since 2001

(formerly: KOMPOZYTY (COMPOSITES) - to 2011 - ISSN 1641-8611)

The publication is indexed by:

Scopus
Emerging Sources Citation Index (ESCI - Thomson Reuters; Clarivate Analytics)
Chemical Abstracts Service
journals scored by the Ministry of Science and Higher Education (Poland)
Library of Congress (USA)
National Library of Poland
BazTech
IndexCopernicus

the Journal is also distributed to libraries and scientific institutions.

Publisher:

Polish Society of Composite Materials Publishing Services

Al. Armii Krajowej 19

42-200 Częstochowa, Poland

tel. +48 34 325 07 21

E-mail: ptmk@ptmk.net

Statistical editor: Ewa Majchrzak
Language editor: Christine Frank-Szarecka
Technical corrector: Zdzisława Tasarz
Typesetting and paging: Dorota Boratyńska

Distribution:

tel. +48 34 325 07 44;

E-mail: ptmk@ptmk.net

Issues 200 copies

Subscription:

tel. +48 34 325 07 44;

E-mail: ptmk@ptmk.net

Annual subscription price 36 EUR (pinted version)

Single issue price 9 EUR (pinted version)

The electronic version is available without restrictions (free of charge to all readers).

(Polish Society of Composite Materials, Poland)

Printed version of the Journal is its original.

Recent Articles

2022

Quarterly No. 4, 2022 - show articles

PROPERTIES OF DEVELOPED SYNTHETIC LIGHTWEIGHT AGGREGATE (COMPOSITE) BASED ON HYDRAULIC BINDERS AND WASTEMarcin Głodniok, Jerzy Korol, Paweł Zawartka
pages 191-195
keywords: sewage sludge, synthetic lightweight aggregate, granulates
article version pdf (0.47MB)

Lightweight aggregates developed on the basis of hydraulic binders and mining waste were investigated in the study. Original technology was utilized to obtain the aggregates. The synthetic aggregate materials obtained in the work satisfy the basic requirements for materials used in construction. Granulates were obtained by granulating raw materials with a counter-current high intensity mixer having a nominal capacity of 30 litres. A rotary tube furnace was selected as the most appropriate to sinter the produced granulates. The process combined two operations: burning the combustible fractions (sewage sludge) responsible for porosity, and sintering (consolidating) the granulate. The sintering process was conducted at the temperature of 950°C in the presence of air. The working reactor tilt was about 2°. Initially the rotational speed for the quick tests was 4.28 rpm, which yielded a granule residence time of about 7.3 minutes in the heating zone (a variant was applied for the tests). The obtained aggregates were subjected to strength testing, and their crushing resistance was determined based on standard PN-EN 13055-1. Depending on the proportions of the individual raw materials, the aggregates are characterised by high crushing resistance from 4.1 to 6.5 MPa, which confirms the potential for their industrial application. These aggregates may be used for purposes such as lightweight building and pavement concrete production due to their relatively low bulk density.

EFFECT OF INJECTION PARAMETERS ON TENSILE AND FLEXURAL PROPERTIES OF GREEN COMPOSITESRajat Rathore, Saugata Bhattacharjee, Prayas Bora, Gorrepotu Surya Rao, Sutanu Samanta, Kishore Debnath
pages 196-204
keywords: natural fibre, biodegradable polymer, green composites, injection moulding, mechanical properties
article version pdf (3.55MB)

Natural fibres are used to develop green composites due to their environmentally friendly nature, ease of availability, low cost, higher strength, as well as good thermal, acoustic, and insulating properties. In this study, jute fibre (JF) and sisal fibre (SF) were considered as reinforcement and a biodegradable polymer, namely polylactic acid (PLA), was selected to fabricate the composites by the injection moulding process. The fibres were chemically treated with sodium hydroxide (NaOH) at a concentration of 2% to improve the characteristics of the fibre. The effect of the injection moulding parameters like injection pressure (bars), injection speed (mm/s), and melting temperature (°C) on the tensile and flexural properties of the sisal fibre/polylactic acid (SF/PLA) and jute fibre/polylactic acid (JF/PLA) composites were investigated. Taguchi’s L9 orthogonal array was chosen for the design of experiments, and analysis of variance (ANOVA) was performed to find the significance and contribution of the selected parameters. The optimum levels from the main plots of both the tensile and flexural strength of the JF/PLA composite were found to be the injection pressure of 90 bars, injection speed of 60 mm/s, and injection temperature of 165°C. Meanwhile, the optimum level of tensile strength for SF/PLA-based composite was recorded as the injection pressure of 70 bars, injection speed of 40 mm/s, and temperature of 165°C. For the flexural strength, the optimum level was determined as the injection pressure of 90 bars, injection speed of 60 mm/s, and temperature of 165°C.

STRESS AND FAILURE ANALYSIS OF COMPOSITE PLATES WITH CIRCULAR HOLE SUBJECTED TO SHEAR LOADING. PART 1: ANALYTICAL AND FINITE ELEMENT FORMULATIONAbdelhak Khechai, Abdelouahab Tati, Mohamed-Ouejdi Belarbi, Fares Mohammed Laid Rekbi
pages 205-210
keywords: anisotropic plates, stress concentration, circular cutout, failure criterion, shear loading
article version pdf (0.63MB)

This current paper, which is the first part of two parts of a complete article, presents the theoretical and finite element formulation developed and proposed by the authors to obtain the stress concentration factors (SCFs) and the first ply failure (FPF) loads of composite laminated plates. The numerical studies are performed using a quadrilateral finite element of four nodes with thirty-two degrees of freedom. The present finite element was previously developed by the authors to study the bending and buckling of composite plates. The present finite element is a combination of two finite elements. The first one is a linear isoparametric membrane element, and the second one is a high-precision rectangular Hermitian element. In the second part of the paper, several examples will be considered to demonstrate and affirm the accuracy and the performance of the present element, as well as highlight the effect of some parameters on the stress distribution. The FPF strengths and their locations in laminated plates with and without holes are calculated by adapting the Hashin-Rotem, Tsai-Hill, and Tsai-Wu failure theories.

MANUFACTURING AND PROPERTIES OF Al-Al ALLOY BIMETALLIC COMPOSITES OBTAINED FROM POWDERS BY HOT EXTRUSIONMarek Wojtaszek, Krystian Zyguła
pages 211-218
keywords: bimetallic composites, hot extrusion, powder metallurgy, aluminum, microstructure, properties
article version pdf (5.19MB)

This paper presents the process of manufacturing bimetallic composites in the shell-core system. Al17Si5Fe3Cu1.1Mg0.6Zr alloy powder was used for the shell. Pure aluminum was used as the core of the composite, respectively, in the form of a cast and then rolled rod, and in the form of a semi-finished product obtained from aluminum powder. The semi-finished powders were produced by means of the uniaxial hot pressing method. From the components prepared in this way, an extrusion charge was made by machining in an alloy shell-core system. Permanent bonding of the components and forming the required shape of the composites was carried out using direct hot extrusion under isothermal conditions. It was confirmed that the application of powder metallurgy technology for the production of one or both component materials makes it possible to conduct the extrusion of the components with significantly different plasticity without violating the cohesion of the layers. This approach made it possible to produce layered composites with high-strength properties of the outer layer and with a ductile core. The microstructural state of the components was evaluated, focusing on the continuity of the transition zone between the components. Observations of the separation lines between the layers revealed that the zone between the components was continuous, which was found for both composites, regardless of the examined cross-section. On this basis, it was concluded that the direct hot extrusion process, carried out under the adopted parameters, made it possible to combine the components very well. Selected properties of the layered composites were also determined. It was shown that the proposed method, combining powder metallurgy and hot forming technologies, makes it possible to obtain a continuous connection of components and produce products with properties significantly differentiating in the core and shell zones. These properties can be controlled by appropriate selection of the components, as well as by the method of manufacturing the core. Potential applications of the studied materials include the manufacture of bimetallic components for operation in conditions where significantly different properties of the outer zone and the core are required.

MICROSTRUCTURE, MECHANICAL PERFORMANCE AND WEAR BEHAVIOR OF AZ91D-B4C-ZrO2 HYBRID COMPOSITESSingaiah Gali, Prasanna Prattipati
pages 219-224
keywords: AZ91D, hybrid composite, zirconia, boron carbide, coefficient of friction, wear
article version pdf (0.64MB)

The stir casting process was used to produce AZ91D magnesium alloy hybrid composites reinforced with boron carbide (B4C) and zirconia (ZrO2). The microstructure of the composites revealed heterogeneity in the reinforcing phase distribution. A pin-on-disc test was conducted to investigate the tribological features of the fabricated composites such as the wear and coefficient of friction under dry sliding conditions. Increased hardness was observed for the composites due to the dispersion of the reinforcement. The composite with 2 wt.% ZrO2 + 3 wt.% B4C exhibited a higher yield strength and increased tensile strength compared with the other specimens. It was observed that the addition of B4C and ZrO2 improved the wear resistance of the AZ91D alloy as reflected by the lower wear rate. Among all the specimens, the composite reinforced with 2 wt.% ZrO2 + 3 wt.% B4C has the highest wear resistance. Hence, it can be concluded from the present work that incorporating B4C and ZrO2 is a promising way to achieve better mechanical properties and wear properties of AZ91 composites.

STRESS AND FAILURE ANALYSIS OF COMPOSITE PLATES WITH A CIRCULAR HOLE SUBJECTED TO SHEAR LOADING. PART 2: RESULTS AND DISCUSSIONSAbdelhak Khechai, Abdelouahab Tati, Mohamed-Ouejdi Belarbi, Fares Mohammed Laid Rekbi
pages 225-232
keywords: anisotropic plates, stress concentration, circular cutout, failure criterion, shear loading
article version pdf (0.73MB)

This paper, the second part of two parts of a complete paper, presents the analytical and numerical results of stresses around circular cutouts in anisotropic and isotropic plates under shear loading. The main aim of this study is to understand the effect of the presence of cutouts on the stress concentration and failure mechanisms in composite laminates. The numerical investigations are performed by means of the quadrilateral finite element of four nodes with thirty-two degrees of freedom. The present finite element is a combination of two finite elements. The first one is a simple linear isoparametric membrane element and the second one is a high-precision rectangular Hermitian element. The analytical and finite element formulations were presented in the first part of the paper. Several new examples are considered to demonstrate and affirm the accuracy and the performance of the present element and to highlight the effect of some parameters on the stress distributions. The numerically obtained results are found to be in good agreement with the analytical findings. On the other hand, first ply failure (FPF) strengths in laminates with and without holes are calculated by adapting the Hashin-Rotem, Tsai-Hill, and Tsai-Wu failure theories. Finally, the numbers of the figures are obtained, using various E1/E2 ratio values, for the maximum positive and negative stresses values located in the vicinity of the cutout versus the angular location of points, and for various fiber orientation angles.

ACKNOWLEDGEMENTS TO REVIEWERS FOR YEAR 2022Composites Theory and Practice
pages 233-234
keywords:
article version pdf (0.19MB)

COMPOSITES THEORY AND PRACTICE JOURNAL PROCEDURESComposites Theory and Practice
pages 235-236
keywords:
article version pdf (0.07MB)

ETHICS IN PUBLISHINGComposites Theory and Practice
pages 237-238
keywords:
article version pdf (0.06MB)

Quarterly No. 3, 2022 - show articles

INVESTIGATION OF GLASS FIBER INFLUENCE ON MECHANICAL CHARACTERISTICS OF NATURAL FIBER REINFORCED POLYESTER COMPOSITES: AN EXPERIMENTAL AND NUMERICAL APPROACHDeepak Kumar Mohapatra, Chitta Ranjan Deo, Punyapriya Mishra
pages 123-129
keywords: glass fiber, kenaf fiber, palmyra palm leaf stalk fiber, mechanical strength, ANSYS
article version pdf (0.61MB)

In the past few decades, natural fiber reinforced polymeric composites have gained significant importance for various structural applications in different sectors like the automotive, aerospace, sports and building construction industries. However, hybridizations make the composite more versatile in term of strength, weight and its processing for many engineering applications. In the current study, a polyester resin matrix was reinforced with two different natural fibers, namely kenaf and palmyra palm leaf stalk (PPLS) and hybridized with glass fiber. Four layers of two different fiber mats, kenaf/glass and PPLS/glass with different stacking sequences were employed to fabricated laminates by the hand lay-up technique. In this case, an attempt was made using the numerical approach to investigate the influence of glass fiber on the mechanical characteristics of the laminates. To substantiate the results of the numerical approach, experiments were conducted. Enhancement of both the tensile and flexural strength was observed due to hybridization of both the kenaf and PPLS fiber with glass fiber. The tensile and flexural strength improved by 68.91 and 37.63% respectively when the kenaf fiber was hybridized with glass fiber. Similarly, enhancement of 54.42% of the tensile strength and 15.92% of the flexural strength were noticed when the PPLS fiber was hybridized with glass fiber. Through the use of ANSYS software, finite element analysis (FEA) was employed as a simulation method to examine the tensile and flexural strength. The numerical findings were found to be quite close to the experimental results, with a variation of less than 3%.

NUMERICAL ANALYSIS OF INTERFACIAL DEBONDING OF METAL/CERAMIC BIMATERIAL USING FEMSara Ramdoum, Boualem Serier, Luciano Feo
pages 130-134
keywords: stresses, crack, interface, bimaterial, FEM
article version pdf (0.53MB)

The bimaterials applied in various fields of industry consist mainly of ceramics and metal. Their damage is mainly due to the presence of residual stresses generated during their manufacture. The damaged area is closely related to the high production temperature. The aim of this study is to analyze the effect of these factors on the behavior of an interfacial and subinterfacial crack in the volume of alumina material. This behavior is studied in terms of variation of the stress intensity factor (SIF) in Modes I, II and III. A study by means of the finite element method (FEM) was carried out. This work demonstrates that the risk of sudden propagation of these cracks is all the more probable when the bimaterial is produced at high temperatures. The elastoplastic behavior of the metal considerably minimizes this risk by plasticizing the metal, which allows strong relaxation of the residual stresses.

SCRATCH BEHAVIOUR OF SURFACE MODIFIED HOLLOW GLASS MICROSPHERE FILLED PC/ABS COMPOSITESB.L.N. Krishna Sai, Pankaj Tambe
pages 135-141
keywords: polycarbonate (PC), normal load, hollow glass microspheres (HGMs), scratch, blend
article version pdf (0.54MB)

In this paper, hollow glass microspheres (HGMs) were surface treated using a silane coupling agent to coat the surface with an amine functional group. Modified and unmodified HGM filled polycarbonate (PC)/acrylonitrile butadiene styrene (ABS) (70/30 wt.%) composites were prepared using a twin-screw extruder and then injection moulding. By means of FTIR spectroscopy, it was found that the modified HGMs containing the amine group formed an aminolysis compound with the PC phase. Scratch studies were performed at low load to avoid fracturing the composites during the test so that deformation of the material only happened in order to understand the influence of HGMs and modified HGM on the scratch behaviour of the composites. The silane modified HGM filled PC70/ABS30 composites exhibited improvement in scratch behaviour as compared to the composites containing unmodified HGMs. The 5 wt.% HGM-NH2 filled PC70/ABS30 composites demonstrate good improvement in scratch resistance as they attained the the highest values of scratch force, coefficient of friction and scratch hardness among all the compositions of composites.

PREDICTION OF COMPRESSION STRENGTH OF BAMBOO REINFORCED LOW-DENSITY POLYETHYLENE WASTE (LDPEw) COMPOSITESAgha Inya Ndukwe, Solomon Umoh, Chimezie Ugwochi, Christian Ogbuji, Chinedu Ngolube, Ferdinand Aliegu, Lilian Izuegbu
pages 142-149
keywords: composite, compression strength, carbonized bamboo, low-density polyethylene waste, artificial neural network, multiple regression, hardness
article version pdf (0.69MB)

In this work, the compression strength of bamboo reinforced low-density polyethylene waste (water sachet waste) composites was predicted. The composites were produced using the compression moulding technique with the following formulations: LDPEw, 5, 10, 15, and 20 wt.% filler. The hardness and compression strength of the examined composites were found to increase when the amount of filler was raised, with the formulation containing 20 wt.% filler having the highest hardness and compression strength values of 59.37 HV and 12.72 MPa, respectively. The control (LDPEw) gave the lowest values of hardness (41.57 HV) and compression strength (8.6 MPa). Multiple regression (MR) and artificial neural networks (ANN) were utilized to predict the experimental compression strength of the produced composites with the hardness and filler composition as independent variables. The mean squared error results indicated that when compared with the multiple regression forecasts, the artificial neural network predictions not only had smaller errors but were also closer to the experimental compression strength values. It is recommended that other methods of producing composites, such as the pulverization process with a 40% higher filler content than what was used in this work, should be studied to ascertain if they provide better composite materials.

HARDNESS AND DRY SLIDING WEAR BEHAVIOUR OF Al7050 HYBRID COMPOSITES PRODUCED BY STIR CASTINGKatepalli Srivallirani, M Venkateswara Rao
pages 150-159
keywords: Al7050, TiO2, h-BN, stir casting, SEM, mechanical wear, XRD
article version pdf (1.66MB)

The current study aims to investigate at the tribological properties of Al7050 reinforced with TiO2 and BN particles utilising a pin-on-disc apparatus. By means of the stir-casting process, MMCs were fabricated with three different weight percentages of TiO2 particles: 1, 3, and 5%, as well as various weight percentages of h-BN particles: 2, 4, and 6%. The volumetric wear rates and coefficients of friction were continuously recorded under normal loads of 20-40 N, sliding speeds of 2-4 m/s and for sliding distances of 1000, 1500 and 2000 m. Microstructural analysis revealed that the TiO2 and BN particles were uniformly dispersed throughout the Al7050 matrix with minimal agglomeration. The experimental data reveals that the tensile strength and Vickers hardness of the cast hybrid composites gradually improved by increasing the weight percentages of the TiO2 and h-BN reinforcing particles. The worn micrographs reveal that abrasion and delamination are the dominant wear mechanisms in the case of the hybrid composites. The composite containing 6 wt.% h-BN particles had the lowest coefficient of friction and wear rate at a normal load of 40 N, sliding speed of 4 m/s and for the sliding distance of 2000 m when compared to other composites. On the other hand, the composites with 2 wt.% h-BN particles had the highest coefficient of friction and wear rate. The XRD analysis showed the generation of strong interfacial reactions, which contributed to the hardness of the hybrid composites.

THERMAL, MECHANICAL AND MOISTURE PROPERTIES OF POLYMER PLASTER MODIFIED WITH LIGHTWEIGHT FILLERSIzabela Marchewka, Ewa Downar-Zapolska, Waldemar Pichór
pages 160-165
keywords: lightweight fillers, polymer plaster, thermal insulating, hollow glass microspheres, expanded glass
article version pdf (0.61MB)

Thermally insulating lightweight plasters are urgently needed for the development of sustainable energy-saving buildings. The creation of such a material is possible because of the use of lightweight fillers, which are of interest to many researchers. As a result of their porous structure, it is possible to lower the density and thermal conductivity of various materials. The aim of this work is to analyze the influence of hollow glass microspheres in two granulations and expanded glass on the parameters of polymer plaster. Composites containing various amounts of lightweight fillers were prepared. Then, their parameters were compared in terms of the mechanical properties, thermal conductivity, vapor permeability, and water absorption. All three lightweight fillers successfully reduced the density of the polymer mass and improved plaster insulation. The best effect was achieved with both types of hollow glass microspheres. The weight of the polymer binder was reduced by up to 80%. In the case of expanded glass, the density was only reduced by 38%. At the same time, the composites were studied in terms of their mechanical and moisture properties. The specimens with the highest amount of lightweight filler showed significant deterioration in elasticity due to disturbance of the pigment:binder ratio. They cracked at lower deflection angles. By not exceeding 20% of the filler, no effect on flexibility was observed in any of the three investigated fillers. Interpretation of the research results indicates that the studied lightweight fillers allow a plaster mass to be obtained with an extremely low thermal conductivity coefficient, less than 0.086 W/mK. However, while ensuring the optimal proportion between fillers and polymer binder, it is possible to reduce the coefficient to 0.261 W/mK without noticeable deterioration of the mechanical properties.

THERMAL CHARACTERIZATION OF CURING PROCESS IN UNSATURATED POLYESTER RESIN BASED POLYMER CONCRETEJakub Smoleń, Klaudia Tomaszewska, Debela Geneti Desisa
pages 166-171
keywords: curing process, polymer concrete, polyester resin, composites
article version pdf (1.30MB)

This paper presents a description of the temperature changes that take place in the curing system of polymer concrete. The research used polymer concrete composed of 30% by volume unsaturated polyester resin acting as a binder for powder fillers. Among the powder fillers, ground glass waste and sand in a volume ratio of 1:1 were used. The investigations were carried out for three volumes, 10, 100 and 1000 cm3, respectively. The temperature in the central point of the volume (the highest temperature) was measured by the ATD method using a NiCr-NiAl thermocouple, and the temperature on the polymer concrete surface was measured using a thermal imaging camera. The temperature-time course recorded for both the measuring points allowed evaluation of the curing system parameters (gelation time, maximum curing temperature, time to maximumtemperature), important for the processing of polymer concrete. Additionally, the knowledge of the temperature curves enabled a mathematical description of the heat flow between the measuring points. The conducted studies proved that the volume of the mold is important for the maximum temperature and curing time. The work is a continuation of previous research focused on polymer concrete and is an extension of information oriented to the industrial aspect. Knowledge of the temperature peaks and curing time will allow adjustments to be made to the manufacturing processes.

DEVELOPMENT OF Al-Ti-C POROUS STRUCTURES FOR REINFORCING ALUMINUM MATRIX COMPOSITESAnna Dmitruk, Krzysztof Naplocha
pages 172-177
keywords: Al-Ti-C, preform, SHS synthesis, microwave, metal matrix composite, MAX phase
article version pdf (2.65MB)

Open-porous preforms from Al-Ti-C compounds were successfully ignited and synthesized by combustion synthesis in a microwave field. The reaction course and the temperature were remarkably affected by the preparation method and molar ratio of the substrates, as well as the position of the green sample in the microwave field generated by a single mode microwave reactor. The manufactured structures were characterized by SEM investigations. The addition of aluminum powder to the mixture moderates the reaction and temperature variations, allowing the course of synthesis in explosive mode to be avoided. Among the reported developed materials the following can be distinguished: Ti-Al intermetallics, titanium carbides and MAX phases belonging to the Ti-Al-C system. The prepared and selected Al-Ti-C preforms were subsequently infiltrated with an AlSi12 aluminum alloy by the squeeze casting method. The composite materials exhibit a relatively homogeneous microstructure with low residual porosity and a good reinforcement/matrix interface.

CHARACTERIZATION OF SiC PARTICLE REINFORCED COPPER MATRIX COMPOSITE WITH COPPER WIRE STRUCTUREAshish Singh, Rajeev Srivastava, Vijay Singh Bisht, Prabhakar Bhandari
pages 178-183
keywords: metal matrix composite, copper wireframe structure, SEM, hardness, compressive strength
article version pdf (4.36MB)

Composites have become a very important class of materials in our everyday life. In the present work, the effect of a copper wireframe structure in SiC particle reinforced copper matrix composites on the compressive strength and other physical properties was analysed. SiC particle reinforced copper matrix composites with and without a copper wireframe structure were fabricated by the powder metallurgy method and sintering was performed at 700°C in atmospheric condition. The copper wire used for making the wireframe structure has diameters of 0.2 and 0.3 mm. A scanning electron microscope (SEM) with magnification of 500X was used to characterize the sintered composites. In addition, hardness tests were performed on a Vickers hardness testing machine and compression testing was carried on a UTM machine. It was observed that the formation of Cu reinforced with 5-7 wt.% SiC and 0.1-0.2 wt.% copper wireframe structure composites was successful. It can be concluded that the hardness of the Cu-SiC composite rises with the increase in the wt.% of reinforcement, while the copper wireframe structure in the composite had a negligible effect on the hardness. However, the addition of the copper wireframe structure resulted in increased compressive strength.

INFLUENCE OF SONICATION ON GRAPHITE AND GLASSY CARBON PARTICLE SIZE DISTRIBUTION IN EPOXY MATRIX AND MECHANICAL PROPERTIES OF PRODUCED COMPOSITESJakub Jała
pages 184-188
keywords: epoxy composite, glassy carbon, sonication, powder treatment, mechanical properties
article version pdf (0.41MB)

In the following study the influence of the ultrasonic treatment of graphite and glassy carbon powder reinforcement on epoxy composites was examined. Sonication treatment was applied to ethanol dispersions of graphite and glassy carbon respectively. After ultrasound treatment the dispersions were dried at the temperature of 70°C. Subsequently, the graphite and glassy carbon powders were mechanically extracted. The produced powders were then analyzed – the grain size distributions of the pre- and post-treatment powders were compared. The results show that the grain sizes of the sonicated graphite decreased, while the glassy carbon particles were not significantly influenced. Epoxy resin composites were made with the pre- and post-treatment powders as reinforcement. The mechanical properties of the prepared composites were examined using a Brinell hardness tester and a tensile tester. The results show slight changes in the mechanical properties of the composites reinforced with the sonicated powders in comparison to the non-sonicated powders and the neat resin samples.

Quarterly No. 2, 2022 - show articles

WATER ABSORPTION BEHAVIOR AND ITS EFFECT ON CHARPY IMPACT TEST OF JUTE YARN REINFORCED POLYESTER COMPOSITESDjamel Djeghader, Bachir Redjel
pages 65-71
keywords: jute, polyester, absorption, Charpy impact test, immersion, diffusion
article version pdf (0.83MB)

Plates of bidirectional jute/polyester composite material were manufactured by the contact molding method. These plates were cut to form notched test pieces 80x15x4 mm and immersed in water (1, 10, 30, 90, 180 and 270 days) in order to study the impact behavior of this material. The studied composite exhibited a water saturation limit after an immersion period of approximately 30 days, with Fickian diffusion of water within the material. Williams’ method based on linear elastic fracture mechanics was used to calculate impact toughness GIC, which is due to the intrinsic characteristics of the material.

ALUMINIUM OXIDE (Al2O3)-FEW LAYER GRAPHENE (FLG) REINFORCED ALUMINIUM HYBRID COMPOSITESCantekin Kaykilarli, Zehra Altinisik, E. Can Kilic, Deniz Uzunsoy, H. Aygul Yeprem
pages 72-78
keywords: Al matrix composites, Al6061, aluminium oxide, few-layer graphene, powder metallurgy, hardness
article version pdf (3.59MB)

The present study investigates the microstructural and mechanical properties of few layer graphene (FLG, 0.1 to 5 wt.%) and aluminium oxide (Al2O3, 4 to 20 wt.%) reinforced Al6061 matrix composites prepared via mechanical alloying (MA), uniaxial pressing and pressureless sintering. The effects of the amounts of Al2O3 and FLG were studied. MA was carried out at 300 rpm for 3 h in a planetary ball mill in argon atmosphere. The mechanically alloyed (MAed) powders were compacted via uniaxial pressing (400 MPa) and sintering (620°C, 2 h). The microstructural and mechanical properties of the Al-xAl2O3-yFLG powders and bulk samples were investigated via X-ray diffraction (XRD), light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), the Archimedes’ method and a hardness test. In the XRD analysis, the aluminium carbide (Al4C3) phase was not detected. The SEM, LM micrographs and EDS results show that the produced composites have a homogeneous structure. Based on the Archimedes’ method, the densification rates of the reinforced samples were higher than the unreinforced sample. The Al-20Al2O3-3FLG sample exhibited the highest relative density, 99.25%. According to the hardness measurements, the highest hardness value was 87.28 HV for the Al-20Al2O3-1FLG composite and increased twofold compared to Al6061.

EFFECT OF TiB2 ON TRIBOLOGICAL PROPERTIES OF AS-CAST Zn-Al-Cu/SiC COMPOSITES USING TAGUCHI AND ANOVA TECHNIQUESRohinikumar Chebolu, Ramanaiah Nallu, Ratnam Chanamala
pages 79-86
keywords: Zn-Al-Cu alloy, HMMC, tribological properties, Taguchi and ANOVA
article version pdf (0.62MB)

The present study presents an evaluation of the tribological properties of the as-cast Zn-Al-Cu alloy-based hybrid metal matrix composite and also the effect of the weight percent of TiB2. The hybrid composites were fabricated using ultrasonic assisted stir casting with 5 wt.% silicon carbide (SiC) and varying X wt.% (0, 5, 10) of titanium diboride (TiB2). A pin-on-disc type tribometer was used to ascertain the tribological properties like the wear rate and coefficient of friction (COF). The influence of various parameters like the weight percentage of TiB2 particles (0, 5 and 10 %), loads (10, 20 and 30 N) and sliding speeds (0.25, 0.5 and 1 m/s) on the tribological behaviour was determined using the L9 orthogonal array for Taguchi and ANOVA.

EVALUATION OF EFFECT OF MACHINING PARAMETERS ON SURFACE ROUGHNESS IN DRILLING OF GLASS FIBER REINFORCED POLYMER (GFRP) COMPOSITE MATERIAL WITH DIFFERENT DRILL BITSMeltem Altin Karatas
pages 87-91
keywords: glass fiber reinforced polymer composite, drilling, surface roughness, Taguchi method
article version pdf (0.52MB)

In the present study, the arithmetical mean roughness (Ra) values obtained as a result of drilling glass fiber reinforced polymer (GFRP) composite material produced in fiber orientation angles (0º/90º) with different drill bits in a 5-axis CNC controlled vertical machining center, were analyzed. The experimental design was applied with the Taguchi method. The drilling experiments were performed using Minitab 19 software according to the Taguchi L18 orthogonal array. The test results were evaluated based on the signal-to-noise (S/N) ratio. Two different drill bits (HSS and carbide), three different spindle speeds (750, 1000, 1500 rpm) and three different feed rates (0.05, 0.10, 0.15 mm/rev) were selected as the control factors. The effect levels of the control factors on Ra were found by applying analysis of variance (ANOVA). A confidence level of 95.62% was obtained with ANOVA analysis. The lowest Ra value was 1.279 μm at the spindle speed of 1500 rpm and the feed rate of 0.05 mm/rev using a carbide drill bit. The drill bit type was obtained as the parameter with the highest effect with a rate of 61.33%.

Deficiency-surplus transition function (DeSuTra) in semi-empirical formulas for tumbling of freely falling cardVladimirs Vorohobovs, Martins Kleinhofs
pages 92-98
keywords: phenomenology, heuristics, semi-empirical research, tumbling cards, Magnus effect, autorotation, lift force, bifurcation, efficiency reducer, efficiency diminisher, DeSuTra function, singularity
article version pdf (0.59MB)

A new phenomenological method for composing analytical formulae to describe dynamic systems using the DeSuTra function as a building block is introduced. Based on heuristic considerations, it is possible to write a correct formula with several unknown coefficients. Next, these coefficients are tuned such a way that the result coincides with the experimental data. To illustrate the viability of such a method, a simple but not trivial aerodynamic system was chosen: the autorotation of a rectangular piece of paper that falls in air. Three correction coefficients (diminishers) were introduced to calculate its rotation frequency. Then a simple expression for the Magnus effect and drag force was used. All the obtained formulae were experimentally proved and the coefficients calculated. The conclusions drawn confirm the usefulness of the presented calculation procedure for the design of composites with chaotically distributed reinforcements.

PROPERTIES AND CHARACTERISTICS OF ALKALI TREATED CALOTROPIS GIGANTEA FIBER-REINFORCED PARTICLE-FILLED EPOXY COMPOSITESR. Jeyapragash, S. Sathiyamurthy, V. Srinivasan, R. Prithivirajan, G. Swaminathan
pages 99-105
keywords: rice husk particles, tensile strength, flexural strength, impact toughness, hardness, water absorption, thickness swelling behaviour, specific wear rate, coefficient of friction
article version pdf (0.90MB)

The presence of particles and fibers as reinforcement in a polymer matrix greatly enhances the mechanical properties. Agricultural residues and natural fibers are commonly used nowadays due to the fact that they easily decompose even after a longer period and they are eco-friendly in nature. Fiber that was extracted from stem of Calotropis gigantea was selected as reinforcement in the present investigation. Initially the fiber was treated with a sodium hydroxide solution and CG fiber-epoxy composites were prepared. The properties of alkaline treated CG fiber-reinforced epoxy composites were further improved by the addition of particles such as chitosan, red mud and rice husk. Properties such as the tensile strength, flexural strength, impact toughness, hardness, water absorption, thickness swelling behaviour, specific wear rate and coefficient of friction were evaluated and compared. The XRD pattern of the chemically treated CG fiber-reinforced parrticle-filled epoxy composites was presented in the present study.

A STUDY ON MECHANICAL AND WEAR BEHAVIOUR OF GRAPHITE FILLED SISAL-GLASS-EPOXY HYBRID COMPOSITESSuresh Kumar Devendrappa, Sanjeevamurthy, Mallesh Goud, Pavankumar Ravikumar, Vasanth Kumar Hasthinapura Seena Naik
pages 106-113
keywords: mechanical and tribological characteristics, sisal, glass, graphite, FRP composites
article version pdf (3.88MB)

In recent years, advancements in development of composite materials can be distinctively observed and taking ecological factors into account, researchers are currently working on the development of natural fibre composites for various applications. The current work concentrates on assessment of the mechanical and wear characteristics of sisal-glass (natural and synthetic) epoxy hybrid graphite filled composites. A comparative characteristic study was performed in the study between synthetic (glass) and natural (sisal) FRP composites and it was found that graphite filled FRP composites exhibit excellent tensile properties, flexural modulus enhanced by 35.2%, the hardness and impact strength were improved with the addition of graphite filler. Statistical analysis was conducted using the design of experiments with the help of ANOVA software. From the tribology tests, it was noticed that the COF and wear loss of the composites with the natural reinforcement are comparatively higher than that of the synthetic fibre. It is evident from ANOVA and regression analysis that the reinforcement has 57.99% influence on the wear rate. Due to increased environmental consequences, natural FRP composites are recommended to be used in as automotive brake friction material and aerospace body parts.

DIFFERENT TECHNIQUES OF REPAIRING COMPOSITE STRUCTURES USED IN AIRCRAFTSintija Zeltina, Martins Kleinhofs, Irena Chatys
pages 114-119
keywords: composite materials, components, repair ways
article version pdf (0.28MB)

The paper presents a fairly extensive review of the procedures and recommendations for checking the damaged repair area of various composite structures (such as sandwich or honeycomb structures) of airframe elements in military and civil airplanes (especially Boeing and Airbus airplanes and sailplanes). The presented requirements for the inspection and assessment of damage (e.g. delamination in layers or in the honeycomb, internal delamination in the laminate, and damaged fibers) should not exceed the permissible damage limits (PDL). The repair requirements (to ensure the continuing airworthiness of the structure) are largely dependent on the classification of the structure under consideration. In these analyses, a fairly important function is performed by non-destructive methods (such as ultrasonic bond testing or using eddy currents), thus assessing the degree of damage and the ongoing maintenance process.

Quarterly No. 1, 2022 - show articles

MODELLING OF LINEAR ELASTICITY AND VISCOELASTICITY OF THERMOSETS AND UNIDIRECTIONAL GLASS FIBRE-REINFORCED THERMOSET-MATRIX COMPOSITES – PART 1: THEORY OF MODELLINGMarian Klasztorny, Daniel B. Nycz
pages 3-15
keywords: thermoset, unidirectional glass fibre-reinforced thermoset-matrix composite, rheological modelling, constitutive equations of linear elasticity-viscoelasticity, analytical modelling
article version pdf (0.30MB)

The paper presents advanced analytical modelling of the linear elasticity and viscoelasticity of thermosets and unidirectional long glass fibre-reinforced thermoset-matrix (UFRT) composites. New non-aging materials fully relaxed after the curing and post-curing processes are considered. Quasi-static long-term isothermal reversible viscoelastic processes under normal condi-tions are modelled. The thermosets are isotropic materials with viscoelastic shear strains and elastic bulk strains, and the fibres are isotropic and elastic. New rheological models for thermosets and UFRT composites, described by the smallest possible number of material constants, are developed. The viscoelastic generic function for shear/quasi-shear stresses is assumed as the Mittag-Leffler fractional exponential function in an integral form. The thermoset is described by two elastic and three viscoelastic parameters. The homogenized UFRT composite is described by five elastic and five viscoelastic parameters. Conjugated/unconjugated standard/inverse constitutive equations of the linear elasticity/elasticity-viscoelasticity governing thermosets and UFRT composites are formulated. The equations are mutually analytically transformable.

EFFECT OF NANO-KAOLINITE WEIGHT FRACTION ON INTERFACIAL SHEAR STRENGTH OF FIBRE REINFORCED NANOCOMPOSITEHisham Mohammed Ali Hasan, Bahaa Aldin Abass Hasan
pages 16-20
keywords: epoxy, nano-kaolinite, Kevlar fibre, polypropylene fibre, drag-out test, interfacial shear strength
article version pdf (1.01MB)

Many studies around the world focus on the use of organic and inorganic additions to polymer composites to enhance their mechanical properties. Investigations were conducted to study the mechanical properties of composites with nano-kaolinite weight fractions of 1, 3, 5, 7, and 12% incorporated into an epoxy matrix. Further investigations were carried out on the diffusion of the epoxy nano-kaolinite monomer into the interfibrillar space when polypropylene and Kevlar rope fibre were added. The Kevlar fibre/matrix and polypropylene fibre/matrix interfacial shear strength was evaluated by the single fibre drag-out method. The highest interfacial shear strength was observed at a 5 wt.% nano-kaolinite content. Energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM), as well as characterisation by X-ray diffraction (XRD), were performed on all the epoxy/nano-kaolinite, Kevlar specimens.

SELECTED PROPERTIES OF POLYPROPYLENE-TiO2 COMPOSITE AFTER EXPOSURE TO UV RAYS – PRELIMINARY STUDYPiotr Olesik, Aleksander Peryt, Krzysztof Stępień, Violetta Frączek, Krzysztof Mackiewicz, Weronika Molka, Oliwia Musiał, Weronika Różańska, Marcin Jesionek
pages 21-24
keywords: titanium dioxide, polypropylene, UV degradation
article version pdf (0.98MB)

In this study the mechanical properties of polypropylene (PP) with a small amount of TiO2, after UV-C exposure were preliminarily analyzed. The effectiveness of titanium oxide was evaluated in two alternative applications: TiO2 as the polymer filler and TiO2 as a protective outer coating. The samples were exposed to UV-C rays for 1000 hours. It was found that an addition of 5 wt% TiO2 to PP matrix results in a 60% smaller decrease in Rg after 1000 h of exposure to UV-C than in the case of neat polypropylene. It was also found that the addition of TiO2 to the polypropylene matrix is more effective than TiO2 applied as a coating component. The Rg decrease after exposure is about 35% in this case. The research confirmed that TiO2 submicrometric particles seem to be a very good component in reducing the sustainability of polypropylene to UV radiation.

MODELLING OF LINEAR ELASTICITY AND VISCOELASTICITY OF THERMOSETS AND UNIDIRECTIONAL GLASS FIBRE-REINFORCED THERMOSET-MATRIX COMPOSITES – PART 2: HOMOGENIZATION AND NUMERICAL ANALYSISMarian Klasztorny, Daniel B. Nycz
pages 25-39
keywords: thermoset, unidirectional glass fibre-reinforced thermoset-matrix composite, rheological modelling, experimental tests, numerical analysis
article version pdf (0.85MB)

The study continues the advanced analytical modelling of the linear elasticity and viscoelasticity of thermosets and unidi-rectional glass fibre-reinforced thermoset-matrix (UFRT) composites. The thermosets are isotropic materials with viscoelastic shear strains and elastic bulk strains, and the fibres are isotropic and elastic. The modified homogenization theory for UFRT composites, based on the selected tasks of the linear theory of elasticity, is developed. The modifications include a volumetrically equivalent cylindrical representative volume cell, solutions determined for an isotropic fibre based on the solutions for a mono-tropic (transversely isotropic) fibre, and certain modifications in the third task of the theory of elasticity. The viscoelastic con-stants of the thermoset are derived analytically and validated by fitting of the simulation and experimental shear strains on a logarithmic time scale in the unidirectional tension creep test. The viscoelastic constants of the UFRT composite are derived analytically and validated by fitting of the storage compliances corresponding to the new viscoelastic model and one obtained from the viscoelastic-elastic correspondence principle. The tension creep experiment is performed on the selected structural unsaturated polyester resin. Identification and validation are carried out for that thermoset and the corresponding UFRT com-posite with long E-glass fibres. All the modelling hypotheses are confirmed.

HA-ZnO-Fe3O4 COMPOSITE MANUFACTURED BY WET POWDER METALLURGY PROCESS FOR IMPLANT APPLICATIONSRuchi Gupta, Mayank Agarwal, Vinay Pratap Singh
pages 40-43
keywords: bioceramics, hydroxyapatite, powder metallurgy, microstructure, density
article version pdf (1.27MB)

A hydroxyapatite (HA) based biocompatible and bioactive composite is an appropriate choice for bio-implants. This experimental work presents the influence of ZnO and Fe3O4 on the microstructure of HA-ZnO-Fe3O4 composites synthesized by the wet powder metallurgy process. These composites were characterized using SEM, energy-dispersive X-ray spectroscopy (EDS), and XRD. The obtained results showed the effect of the addition of Fe3O4 on the interface formation, which is exhibited by interconnected pores and sintered neck in the micrographs. The observed porosity helps to enhance the required osseointegration for the fixation of implants with human bones.

DESIGN STUDY OF NATURAL FIBER REINFORCED HONEYCOMB PANEL FOR LIGHTWEIGHT AND PORTABLE SHELTER MATERIALS FOR TYPICAL MALAYSIAN CLIMATEMuhammad Zulkarnain, Khairul Amri Tofrowaih, Yaseen Adnan Ahmed
pages 44-49
keywords: fiber distribution, thermal conductivity, insulating, finite element analysis, honeycomb sandwich
article version pdf (0.47MB)

An evacuation shelter provides simple living facilities made of lightweight materials for repeated use and ensures that the shelters provide a safe and suitable long-term environment. Improving the shelter material in terms of thermal quality in the Malaysian climate is one requirement when evacuating victims to emergency shelters in open areas. The article aims to investigate the effect of using local natural fibers for composite honeycomb skin on the thermal and mechanical performance. The composite skin is a natural fiber processed in a concrete panel to make a honeycomb sandwich. This work introduces a model of natural fiber distribution embedded in a concrete panel, which is subjected to thermal analysis and three-point bending (TPB) to optimize the honeycomb structure. In order to understand the thermal interaction of the panel sheet for an insulating system, the model provides a six-level range of the number of fibers (100, 200, 300, 400, 500 and 600) to analyze the fiber network. The simulation demonstrated that improvement in the insulating panel of about 2.58% could be achieved by using the number of 600 coconut fibers, which is much lower compared to plain concrete. The morphology study successfully demonstrates the understanding of the fiber distribution and thermal absorption by the concrete. Moreover, the mechanical performance is also positively affected by using fiber in the panel, especially sugar cane, which achieved a 47% improvement. This successfully simulated model provides a promising solution to promote local products for shelter material applications.

SELECTED PROPERTIES OF POLYPROPYLENE-BaSO4 COMPOSITES AFTER UV EXPOSUREPiotr Olesik, Krzysztof Stępień, Aleksander Peryt, Piotr Siejka, Szymon Waluś, Karolina Witczak, Weronika Wójcik, Anna Wolanin
pages 50-53
keywords: barium sulfate, polypropylene, UV degradation
article version pdf (0.50MB)

The paper presents a preliminary study on the effect of an addition of barium sulfate (BaSO4) particles on the mechanical properties of polypropylene (PP) and an evaluation of the effectiveness of this additive in protecting the material against UV rays. Tests were carried on PP samples filled with BaSO4 powder and on samples covered with a protective coating based on BaSO4. Samples of the materials were exposed to UV-C rays for 1000 hours. After exposure, specimens were subjected to static three-point bending tests and hardness examination. Based on the obtained results, it was concluded that BaSO4 reduces the decrease in flexural strength and in hardness caused by exposure to UV-C rays by half in comparison with neat PP. The action of BaSO4 particles as a filler of PP and as a component of a coating applied on the surface of the sample results in similar anti-UV protection of the material. BaSO4 seems to be a commonly available and inexpensive anti-UV protector for plastics.

INFLUENCE OF AIR GAP ON INSULATING PROPERTIES OF COMPOSITE COATINGS ON PIPES FOR HOT MEDIA TRANSPORTAndrzej Posmyk
pages 54-57
keywords: composite coating, thermal insulation, air gap, energy losses, industrial pipelines, short distance transport
article version pdf (1.68MB)

The shrinking resources of fossil fuels and the growing pollution of the environment have caused people to begin to search for possibilities of reducing energy losses. Vast possibilities in this area lie in industrial transport, called short distance transport, as well as in civil engineering. European Union authorities set limits for the emission of harmful pollutants and energy losses. That is why the laboratories of many research centres conduct research on composite insulating materials taking into account a nanotechnology and air gaps. The paper presents the results of research on steel pipelines used in the transport of hot media, insulated with PUR shaped materials covered with a composite coating with a polymer resin matrix containing an air gap between PUR and the pipe. Such a solution makes it possible to employ the reflective properties of selected materials, which, thanks to reflection of the heat flux, returns it to the source. An air gap with the thickness of 10 mm under the conditions of the conducted research, allows the heat losses of an steel industrial pipeline to be reduced by 7.6%.

FAILURE MODEL FOR UNIDIRECTIONAL COMPOSITE ELEMENTJuris Gutans, Piotr Zagulski, Druvis Verzemnieks, Martins Kleinhofs
pages 58-61
keywords: failure, fibers, composite, strength, statistical model
article version pdf (0.36MB)

This paper is devoted to important issues of determining the strength and predicting the failure processes of composites. These issues enable determination of the limits of safe use of a product and the recognition of when limits are reached. It investigates the distribution function of the composite and its components. The developed model that is presented in this paper enables description of not only the predictable strength of unidirectional composites, but also the character of the failure, taking into account the fiber stress and/or ultimate strain distribution.