Search results for: STRENGTH PROPERTIES
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Influence of artificial thermal ageing on polyester-reinforced and polyvinyl chloride coated AF9032 technical fabric
PublicationThe presented work deals with the thermal ageing evaluation for polyester-reinforced and polyvinyl chloride coated fabrics. The architectural fabric AF9032 was exposed to artificial thermal ageing by subjecting the material samples to temperature levels of 80℃ and 90℃ for up to 12 weeks. The mechanical properties of the aged fabric have been separately described by the identified linear piecewise model (with assumption of the elastic...
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Thermal and Mechanical Behavior of Elastomers Incorporated with Thermoregulating Microcapsules
PublicationPolyurethane (PU) is one of the principal polymers in the global plastic market thanks to its versatility and continuous improvement. In this work, PU elastomeric materials having thermoregulating properties through the incorporation of microcapsules (mSD-(LDPE·EVA-RT27)) from low-density polyethylene and vinyl acetate containing paraffin®RT27 as PCM were produced. Elastomers were synthesized while varying the molar ratio [NCO]/[OH]...
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Towards understanding the role of peroxide initiators on compatibilization efficiency of thermoplastic elastomers highly filled with reclaimed GTR
PublicationThermoplastic elastomers based on recycled high density polyethylene (rHDPE) and styrene-butadiene-styrene (SBS) block copolymer were highly filled with reclaimed ground tire rubber (RR). The impact of various organic peroxides (dicumyl peroxide (DCP), benzoyl peroxide (BP) and di-tert-butyl peroxide (DB)), applied as free-radical initiators, on the processing, structure and performance properties of rHDPE/SBS/RR blends was investigated....
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Analysis of features of stainless steels in dissimilar welded joints in chloride inducted corrosion
PublicationStainless steels of femtic-austenitic microstructure that means the duplex Cr-Ni-Mo steels, in comparison with austenitic steel includes less expensive nickel and has much better mechanical properties with good formability and corrosion resistance, even in environments containing chloride ions. Similar share of high chromium ferrite and austenite, which is characterized by high ductility, determines that the duplex steels have...
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Overview of planar antenna loading metamaterials for gain performance enhancement: the two decades of progress
PublicationMetamaterials (MTMs) are artificially engineered materials with unique electromagnetic properties not occurring in natural materials. MTMs have gained considerable attention owing to their exotic electromagnetic characteristics such as negative permittivity and permeability, thereby a negative refraction index. These extraordinary properties enable many practical applications such as super-lenses, and cloaking technology, and are...
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Applying of Doped Graphene Oxide Coatings for Corrosion Prevention
PublicationINTRODUCTION Graphene is a carbonaceous material characterized by extraordinary properties (high electron mobility, high surface area, high mechanical strength of 1100 GPa, very dense network hindering the passage of even the smallest helium atoms) [1]. Therefore, it found many applications, also as an anti-corrosive layer [2]. Electrophoretic Deposition (EPD) is one of the methods to deposit coatings. However, due to slight solubility...
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FE analysis of a coupled energetic-statistical size effect in plain concrete beams with varying material properties.
PublicationThe numerical FE investigations of a coupled energetic-statistical size effect in unnotched concrete beams of similar geometry under quasi-static three point bending were performed within elasto-plasticity with non-local softening. The stochastic FE analyses were carried out with three different beam sizes. Deterministic calculations were performed with the uniform distribution of a uniaxial tensile strength. In statistical calculations...
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Poly(ε-Caprolactone)/Poly(Lactic Acid) Blends Compatibilized by Peroxide Initiators: Comparison of Two Strategies
PublicationPoly(ε-caprolactone) (PCL) and poly(lactic acid) (PLA) blends were compatibilized by reactive blending and by copolymers formed during reaction in the solution. The reactive blending of PCL/PLA was performed using di-(2-tert-butyl-peroxyisopropyl)benzene (BIB) or dicumyl peroxide (DCP) as radical initiator. PCL-g-PLA copolymers were prepared using 1.0 wt. % of DCP or BIB via reaction in solution, which was investigated through...
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Rotational Molding of Linear Low-Density Polyethylene Composites Filled with Wheat Bran
PublicationApplication of lignocellulosic fillers in the manufacturing of wood polymer composites (WPCs) is a very popular trend of research, however it is still rarely observed in the case of rotational molding. The present study aimed to analyze the impact of wheat bran content (from 2.5 wt.% to 20 wt.%) on the performance of rotationally-molded composites based on a linear low-density polyethylene (LLDPE) matrix. Microscopic structure...
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Soft-mode enhanced type-I superconductivity in LiPd2Ge
PublicationThe synthesis, crystal structure, and physical properties (magnetization, resistivity, heat capacity) in combination with theoretical calculations of the electronic structure and phonon properties are reported for intermetallic compounds LiPd2X (X = Si, Ge, and Sn). LeBail refinement of powder x-ray diffraction data confirms that all compounds belong to the Heusler family (space group Fm-3m, No. 225). The lattice parameter increases...
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Mechanical behaviour of knit synthetic mesh used in hernia surgery
PublicationPurpose: There is a discussion in literature concerning mechanical properties and modelling of surgical meshes. An important feature of elastic modulus dependency on load history is taken into account in this paper, as implants are subjected to variable loading during human activity. The example of DynaMesh®-IPOM surgical implant is studied. Methods: The analysis is based on failure tension tests and cyclic loading and unloading...
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Structure-property relationships in peroxide-assisted blends of poly(ε-caprolactone) and poly(3-hydroxybutyrate)
PublicationPoly(ε-caprolactone) and poly(3-hydroxybutyrate) (PCL/PHB) blends in two weight ratios (75/25 and 50/50) were reactively compatibilized in the presence of di-(2-tert-butyl-peroxyisopropyl)-benzene and dicumyl peroxide as free radical initiators. Rheological, mechanical, thermal properties and morphological features, as well as the chemical structure of PCL/PHB blends were investigated. It was found that regardless of PCL/PHB blend...
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The estimation of total volatile organic compounds emissions generated from peroxide cured natural rubber/polycaprolactone blends
PublicationNatural rubber (NR)/polycaprolactone (PCL) blends at the ratio of 90/10% wt. (NR/PCL90/10) and 70/30% wt. (NR/PCL70/30), with a constant amount of dicumyl peroxide, were prepared by compounding in an internal mixer. Obtained NR/PCL bio-based blends were cured at three different temperatures (150 °C, 160 °C and 170 °C). The total content of volatile organic compounds (TVOC) as a function of the NR/PCL blends ratio, and their curing...
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Rotational molding of polylactide (PLA) composites filled with copper slag as a waste filler from metallurgical industry
PublicationThe research work carried out so far indicates the ever wider possibilities and demand for shaping composite products in the rotational molding technology. This trend was the main reason to use waste-based filler from the metallurgical process as a filler for manufacturing polylactide (PLA)-based remolded composites. Copper slag (CS) was introduced in the single-step processing method to PLA matrix at 5, 10, 20, and 35 wt%. The...
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On the generalized model of shell structures with functional cross-sections
PublicationIn the present study, a single general formulation has been presented for the analysis of various shell-shaped structures. The proposed model is comprehensive and a variety of theories can be used based on it. The cross-section of the shell structure can be arbitrarily analyzed with the presented equations. In other words, various types of shell structures, including cylindrical, conical, spherical, elliptical, hyperbolic, parabolic,...
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Influence of Material Thickness on the Ductile Fracture of Steel Plates for Shipbuilding
PublicationIn the shipbuilding industry, the risk of brittle fractures is relatively high because some units operate in arctic or subarcticzones and use high thickness (up to 100 mm) steel plates in their structures. This risk is limited by employing certifiedmaterials with a specific impact strength, determined using the Charpy method (for a given design temperature) and byexercising control over the welding processes (technology qualification,...
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Diatomaceous earth as a drug-loaded carrier in a glass-ionomer cement
PublicationThe effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer cement (GIC). Three sample series, differing in DE content (0, 2.5 and 5 wt%), were prepared using a commercial GIC as a matrix (3M Ketac Molar Easymix). The resultant surface microhardness and roughness, wear performance, and compressive strength of the samples were...
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Study on extraction and characterization of anchote (Coccinia abyssinica) starch and reinforced enset (Ensete ventricosum) fiber for the production of reinforced bioplastic film
PublicationPopulation expansion is causing an increase in dependence on plastic materials. The worst aspects of conventional plastics were their inability to biodegrade, their poor capacity to transmit water vapor, and their production of greenhouse gases. Usages of bioplastics are necessary for the advancement of a green economy and environment in order to eradicate these drawbacks of traditional plastics. In this study, reinforced bioplastic...
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Textile reinforced concrete members subjected to tension, bending, and in-plane loads: Experimental study and numerical analyses
PublicationTextile reinforced concrete has raised increasing research interest during the last years, mainly due to its potential to be used for freeform shell structures involving complex load situations. Yet, most experimental work has focused on test setups with primarily uniaxial loading. In the current work, such setups are complemented with a novel test setup of deep beams, including in-plane bending and shear. Further, nonlinear finite...
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Application of advanced spectroscopic methods in the assessment of the leachability degree of hazardous elements from the matrix of cellular concretea
PublicationDue to its structure, autoclaved cellular concrete exhibits good insulating properties with relatively high compressive strength values. It is increasingly used in construction because of its economic attractiveness. Autoclaved cellular concrete is mainly used in interior structure layers, and therefore its potential exposure to heavy metal leaching from the matrix may be related to the presence of a high pH medium from other materials...
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By-Products from Food Industry as a Promising Alternative for the Conventional Fillers for Wood–Polymer Composites
PublicationThe present paper describes the application of two types of food-industry by-products, brewers’ spent grain (BSG), and coffee silverskin (ŁK) as promising alternatives for the conventional beech wood flour (WF) for wood–polymer composites. The main goal was to investigate the impact of partial and complete WF substitution by BSG and ŁK on the processing, structure, physicochemical, mechanical, and thermal properties of resulting...
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MANDARIN PEEL AS AN AUSPICIOUS FUNCTIONAL FILLER FOR POLYMER COMPOSITES
PublicationThis work describes the application of mandarin peel (MP) as a waste filler for high-density polyethylene (HDPE) composites. The main goal was to investigate the impact of the filler's essential oils, which include multiple terpenes and terpenoids, on the processing, physicochemical, mechanical, and thermal properties of the composites as a function of different filler content (1 – 10 wt%), as well as its effect on the color and...
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AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublicationThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
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Impact of laser beam welding on mechanical behaviour of 2.25Cr–1Mo (P22) steel
PublicationThe use of welding processes in the manufacturing and repair of structures intended for the energy industry plays a key role in the guarantee of a continuous supply of fossil fuels, which is the basic condition for ensuring energy security. A square butt joint of 10 mm thick plate of 2.25Cr–1Mo (P22) steel was fabricated by autogenous laser beam welding process and then post-weld heat treatment (PWHT) for two sets of process parameters...
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Consideration of the safety of bungee jumping in relation to mechanical properties of the instalation based on a jump accident in Gdynia
PublicationThis paper considers a bungee jumping accident that took place in July 2019 in Gdynia, Poland. The authors conducted an investigation to determine the cause of the bungee rope failure. It was based on mechanical tests concerning the strength of the rope as well as the calculation of the force induced in the rope during the jump. Based on the theoretical and experimental results, the rope safety factor was estimated. It appeared...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublicationThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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COMPOSITE MATERIAL SELECTION FOR A PATIENT TRANSFER ASSIST DEVICE
PublicationLaminates - layered composites containing at least two elements (matrix and reinforcement) widely used in industry have also found their usage in medicine. Their main feature is the ability to modify the material in order to obtain the required properties. Depending on the needs, we can modify reinforcement, type of resin or the method of bonding substrates. Commonly used fibers are: carbon fiber, glass and aramid fibers; resins...
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Qualification of brazing procedure for furnace brazing of austenitic steel according to requirements of the ASME BPVC section IX
PublicationThe article presents the procedure for qualifying brazing technology in a vacuum furnace on the example of stainless steel elements joined with copper filler material from the F-No group. 105, in accordance with the ASME Sec. IX, part QB (ASME Boiler and Pressure Vessel Code. Qualification Standard for Welding, Brazing and Fusing; Procedures; Welders; Brazers; and Welding, Brazing and Fusing Operators). The essential variables...
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Non-linear strain rate analysis of earthquake-induced pounding between steel buildings
PublicationPast and recent earthquakes have shown that ground motions may cause severe structural damage to civil engineering structures. Earthquake-induced pounding between adjacent buildings has been identified as one of the reasons which intensifies damages. The aim of this paper is to show the results of the detailed nonlinear FEM analysis of earthquake-induced pounding between two steel buildings. The elastic – perfectly plastic material...
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Characterization of Highly Filled Glass Fiber/Carbon Fiber Polyurethane Composites with the Addition of Bio-Polyol Obtained through Biomass Liquefaction
PublicationThis work aims to investigate the process of obtaining highly filled glass and carbon fiber composites. Composites were manufactured using previously obtained cellulose derived polyol, polymeric methylene diphenyl diisocyanate (pMDI). As a catalyst, dibutyltin dilaurate 95% and Dabco® 33-LV were used. It was found that the addition of carbon and glass fibers into the polymer matrix causes an increase in the mechanical properties...
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Copper Slag as a Potential Waste Filler for Polyethylene-Based Composites Manufacturing
PublicationThe present study aimed to analyze the application of waste material from copper production– copper slag (ŻŻL) as filler for composites based on the high-density polyethylene (HDPE). Copper slag filler was introduced in the amounts of 1–20 wt%, and its influence on the appearance (color analysis), chemical structure (Fourier-transform infrared (FTIR) spectroscopy), microstructure (optical microscopy), as well as static (tensile...
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Chitin nanowhiskers from shrimp shell waste as green filler in acrylonitrile-butadiene rubber: Processing and performance properties
PublicationIn this work, chitin nanowhiskers with high crystallinity index were obtained from shrimp shells waste using acid hydrolysis method and then comprehensively characterized. Subsequently, the impact of chitin nanowhisker content on processing and performance of acrylonitrile-butadiene rubber based nanocomposites was evaluated. The results showed that the addition of chitin nanowhiskers increased tensile strength and tear strength...
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Pantographic metamaterials: an example of mathematically driven design and of its technological challenges
PublicationIn this paper, we account for the research efforts that have been started, for some among us, already since 2003, and aimed to the design of a class of exotic architectured, optimized (meta) materials. At the first stage of these efforts, as it often happens, the research was based on the results of mathematical investigations. The problem to be solved was stated as follows: determine the material (micro)structure governed by those...
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The influence of crude glycerol and castor oil-based polyol on the structure and performance of rigid polyurethane-polyisocyanurate foams
PublicationIn this work, biopolyol obtained from two types of industrial crops’ processing products: crude glycerol and castor oil was used for preparation or rigid polyurethane-polyisocyanurate foams. Bio-based polyol was obtained via crude glycerol polymerization and further condensation of resulting polyglycerol with castor oil. Rigid polyurethane-polyisocyanurate foams were prepared at partial substitution (0–70 wt.%) of petrochemical...
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DESIGN OF THE DUAL CONSTELLATION GPS/GALILEO MOBILE DEVICE FOR IMPROVING NAVIGATION OF THE VISUALLY IMPAIRED IN AN URBAN AREA, POLISH MARITIME RESEARCH
PublicationThe article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of...
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IDENTIFICATION OF DAMAGES OF TRIBOLOGICAL ASSOCIATIONS IN CRANKSHAFT AND PISTON SYSTEMS OF TWO-STROKE INTERNAL COMBUSTION ENGINES USED AS MAIN PROPULSION IN SEA-GOING VESSELS AND PROPOSAL OF PROBABILISTIC DESCRIPTION OF LOADS AS CAUSES OF THESE DAMAGES
PublicationThe article discusses damages of essential tribological associations in crankshaft and piston systems of large power two-stroke engines used as main engines, which take place during transport tasks performed by those ships. Difficulties are named which make preventing those damages impossible, despite the fact that the technical state of engines of this type is identified with the aid of complex diagnostic systems making use of...
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Comprehensive Investigation of Stoichiometry–Structure–Performance Relationships in Flexible Polyurethane Foams
PublicationPolyurethane (PU) foams are versatile materials with a broad application range. Their performance is driven by the stoichiometry of polymerization reaction, which has been investigated in several works. However, the analysis was often limited only to selected properties and compared samples differing in apparent density, significantly influencing their performance. In the bigger picture, there is still a lack of comprehensive studies...
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Waste tire rubber devulcanization technologies: State-of-the-art, limitations and future perspectives
PublicationWaste tires management is a serious and global environmental problem. Therefore, searching for low-cost and industrial-scale applicable tire recycling methods is gaining more and more attention. Waste tire rubber is valuable source of secondary raw materials for the circular economy and current trends indicate that application of waste rubbers during manufacturing value-added products should increase in near future. Sustainable...
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Prognozowanie właściwości złączy spawanych pod wodą metodą lokalnej komory suchej
PublicationNiniejsza praca jest poświęcona spawaniu pod wodą metodą lokalnej komory suchej (MLKS) i przedstawia metodologię oraz narzędzia umożliwiające prognozowanie właściwości złączy spawanych wykonanych przy zastosowaniu tej odmiany spawania. Monografia zawiera opis rozwoju spawania pod wodą oraz charakterystykę metod wykorzystywanych do realizacji prac spawalniczych. Zaproponowano nowy podział metod spawania pod wodą, uwzględniający...
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The new silica-based coated SPME fiber as universal support for the confinement of ionic liquid as an extraction medium
PublicationThe new silica-based SPME fiber coating is reported for the first time as universal support purposed to confinement of ionic liquid as an extraction medium. Fiber coating was prepared by the sol-gel process, using potassium silicate (K2SiO3) as a precursor and dimethylformamide (DMF) as a pore-forming medium. The concept of synthesis assumes obtaining a solid porous material on the surface of the glass rod and, being characterized...
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Applying molecular dynamics simulation to take the fracture fingerprint of polycrystalline SiC nanosheets
PublicationGraphene-like nanosheets are the key elements of advanced materials and systems. The mechanical behavior of the structurally perfect 2D nanostructures is well documented, but that of polycrystalline ones is less understood. Herein, we applied molecular dynamics simulation (MDS) to take the fracture fingerprint of polycrystalline SiC nanosheets (PSiCNS), where monocrystalline SiC nanosheets (MSiCNS) was the reference nanosheet....
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Metallurgical characterization and high-temperature tensile failure of Inconel 617 alloy welded by GTAW and SMAW—a comparative study
PublicationTwo types of the weld joint of Inconel 617 alloy were produced using gas tungsten arc welding (GTAW) and shielded metal arc welding (SMAW) processes with ERNiCrCoMo-1 filler metal and ENiCrCoMo-1 electrode, respectively. The weld metal showed the segregation of the principle alloying elements like Mo and Cr along the inter-dendritic spaces, triggering the formation of secondary phases. The microstructure characterization of the...
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The Effects of the “Sling Shot” Device on Bench Press Performance, Mechanical Properties of Muscle, and Movement Kinematics
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Bioactive polyurethanes applied as a surgical implants
PublicationSynthetic materials are applied in many branches of the industry, i.a. in medicine as a casing of apparatus, elements of artificial organs (hearts, blood vessels), catheters, wound healings, intra aortic balloons, mammary implants to mention but a few. Polymeric material used in such applications must be distinguished by a good biocompatybility. Since many years extensive research are employed to develop a new polymers that can...
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Petrophysical analyses of rock construction materials from the Roman rural settlement in Podšilo bay on Rab island (NE Adriatic, Croatia)
PublicationThis article presents the results of petrophysical analyses of limestones and sandstones used for the construction of the wall structures of a Roman rural settlement located in Podšilo Bay on Rab Island (Croatia). An on-site analysis of the walls indicated the use of different lithotypes, which is an uncommon case in the area. So far, no petrophysical properties of the applied materials have been tested, and their provenance...
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Rubber wastes recycling for developing advanced polymer composites: A warm handshake with sustainability
PublicationRecycling and management of rubber wastes experiences an early-stage maturity in the quest for sustainable and circular materials. Up to now, solutions proposed for sustainable development of rubber wastes are limited, so that properties and performance features of recycled products are inadequate for practical applications. Herein, an experimental protocol is introduced for manufacturing semi-sustainable polymer composites based...
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Recycled rubber wastes-based polymer composites with flame retardancy and electrical conductivity: Rational design, modeling and optimization
PublicationPolymer recycling techniques experience a maturity period of design and application. Rubbers comprise a high proportion of polymer wastes, highly flammable and impossible to re-melt. Polymer composites based on ground tire rubber (GTR) and ethylene-vinyl acetate copolymer (EVA) containing carbon black (CB) (1–50 phr), with variable EVA/GTR weight composition (10/90, 25/75, 50/50, 75/25 and 90/10), and processing temperature (Low:...
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Application of Shape Memory Alloys in Retrofitting of Masonry and Heritage Structures Based on Their Vulnerability Revealed in the Bam 2003 Earthquake
PublicationFor decades, one of the most critical considerations of civil engineers has been the construction of structures that can sufficiently resist earthquakes. However, in many parts of the globe, ancient and contemporary buildings were constructed without regard for engineering; thus, there is a rising necessity to adapt existing structures to avoid accidents and preserve historical artefacts. There are various techniques for retrofitting...
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Application of cyanated asphaltenes in gas-phase adsorption processes for removal of volatile organic compounds
PublicationThe paper presents an innovative, chemically modified (methylcyanated) asphaltene-based adsorbent that can be an inter-esting low-cost alternative for traditional adsorbents. Adsorption properties of adsorbents were examined by inverse gas chromatography technique, adsorption isotherms, and breakthrough curves. A significant increase in retention volume for pyridine, 2-pentanone, nitropropane, toluene, and 1-butanol was observed....
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Soiling Effect Mitigation Obtained by Applying Transparent Thin-Films on Solar Panels: Comparison of Different Types of Coatings
PublicationDust accumulation on the front cover of solar panels is closely linked to location and orientation of photovoltaic (PV) installation. Its build-up depends on the module tilt angle, frequency of precipitation, humidity, wind strength and velocity, as well as grain size. Additionally, soil composition is determined by solar farm surroundings such as local factories, agricultural crops, and traffic. Over time, molecules of atmospheric...