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Search results for: POLYMER FLEXIBLE JOINT
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The influence of temperature on properties of the polymer flexible joint used for strengthening historical masonries
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared elastomeric polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure....
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Low-strain sensor based on the flexible boron-doped diamond-polymer structures
PublicationA free-standing high boron-doped diamond nanosheet (BDDNS) has been fabricated for the development of a flexible BDDNS strain senor. High boron-doped diamond was initially grown on a tantalum substrate in a microwave plasma-assisted chemical vapor deposition method, and was then transferred to a Kapton polymer substrate to fabricate the flexible BDDNS/Kapton device. Before performing the transfer process, the thin BDDNS’s morphology...
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Experimental examination of an elastomeric polymer
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared elastomeric polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure....
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Experimental study on static and dynamic properties of polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the...
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Experimental determination of basic mechanical properties of elastomeric polymer
PublicationThere are a lot of different methods of repairing and reinforcing damaged structures, but when it comes to historical buildings and other cultural heritage objects, it is as much about mechanical safety as the aesthetical aspects. Recently, a new and innovative method of repairing damaged structures by filling the cracks with a specially prepared polymer mass has been proposed. This new and innovative technique, known as the Flexible...
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An experimental study on polymer mass
PublicationA new method of repairing damaged structures by filling the cracks with specially prepared polymer mass has been recently proposed. The technique is mainly dedicated to historical objects where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure. The aim of the present paper is to show the results of an experimental study on polymer mass...
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Enhancing the Seismic Resistance of Columns by GFRP Confinement Using Flexible Adhesive-Experimental Study
PublicationIn this paper, the results of two experiments, focused on testing the effectiveness of a method of enhancing the seismic (dynamic) resistance of masonry columns with the use of flexible polymer adhesive, are shown. The first experiment was devoted to investigate the damping properties of a polymer working between two stiff layers, whereas the aim of the second one was to verify if the identified damping properties of the polymer...
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Experimentation, material modelling and simulation of bonded joints with a flexible adhesive
PublicationThe paper deals with material parameters identification of a flexible adhesive and the numerical simulation of its behaviour in a single lap bonded joint. The material modelling was based on the simple shear and tensile-shear laboratory tests of the bonded joints made of thin aluminium and polyurethane plates with the flexible adhesive Terostat MS 9360 manufactured by Henkel AG & Co. The adhesive was considered as a hyperelastic...
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Experimental study on polymer mass used to repair damaged structures
PublicationA new method of repairing damaged structures by injecting the cracks with specially designed polymer mass (flexible two-component grout based on polyurethane resin) has been recently proposed. The technique is mainly dedicated to damaged masonries, especially historical structures where minimum intervention is permitted. The cracks are filled with the special injection, forming the flexible joints bonding the disrupted structural...
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The effectiveness of polymer adhesive in reduction of vibrations of structural members
PublicationIn this paper, the idea of using polymer adhesive as a damping layer is proposed. An experimental study of two aluminium cantilevered beams has been conducted. One of them presents a plain cantilevered beam, while the second one considers two aluminium beams bonded with a polymer adhesive of different thickness (0,5; 1,2; 1,75; 3,1 and 5 mm). The polymer adhesive considered in the study is a specially designed flexible...
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Experimental Study on the Effectiveness of Polyurethane Flexible Adhesive in Reduction of Structural Vibrations
PublicationThe aim of the present study is to consider the idea of using polyurethane flexible adhesive in to reduce the vibrations in structures exposed to dynamic loads and evaluate their damping properties in relation to large deformations. Firstly, two aluminium cantilever beams, simulating structural elements (without and with polyurethane layer in the form of tape), were analysed, in order to check the damping of the unconstrained polymer...
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Investigation on polypropylene friction stir joint: effects of tool tilt angle on heat flux, material flow and defect formation
PublicationTool tilt angle (TTA) is a critical factor that can control material flow in polymeric materials' friction stir joining (FSJ). This study selected a TTA range between 0° to 4° for FSJ of polypropylene (PP) polymer sheet. A modified computational fluid dynamic (CFD) technique was implemented to gain a deep understanding of the effects of TTA during FSJ of PP. The PP joint's internal flow, defect formation, heat generation, and tensile...
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Shaking table experimental study on the effectiveness of polymer bearings for seismic isolation of structures
PublicationSeismic isolation has been recognised to be a very effective way of protecting structures from damage during earthquakes. It allows us to extend the natural period of the structure and therefore avoid resonance with the ground motion. Moreover, by increasing damping in the isolation devices, more energy can be dissipated and thus the structural response can be further reduced. The aim of this paper is to show the results of the...
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The Impact of Ground Tire Rubber Oxidation with H2O2 and KMnO4 on the Structure and Performance of Flexible Polyurethane/Ground Tire Rubber Composite Foams
PublicationThe use of waste tires is a very critical issue, considering their environmental and economic implications. One of the simplest and the least harmful methods is conversion of tires into ground tire rubber (GTR), which can be introduced into different polymer matrices as a filler. However, these applications often require proper modifications to provide compatibility with the polymer matrix. In this study, we examined the impact...
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Monitoring of crosslinking of a DGEBA-PAMAM adhesive in composite/aluminium bonded joint using mechanical and ultra-sound techniques
PublicationAdhesive cure is an important and determining aspect of strength and stability of bonded structures. Crosslinking of the polymer leads to the adhesive strength, stiffness and durability. Depending on the resin and curing agent used, cure time can vary from minutes to weeks, even then 100% crosslinking not being guaranteed. Standard methods based on dynamic mechanical analysis (DMA) or calorimetric techniques (DSC, DTA) are valuable...
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Structural Changes and Their Implications in Foamed Flexible Polyurethane Composites Filled with Rapeseed Oil-Treated Ground Tire Rubber
PublicationThe utilization of post-consumer car tires is an essential issue from an ecological andeconomic point of view. One of the simplest and the least harmful methods is their material recyclingresulting in ground tire rubber (GTR), which can be further applied as fillers for polymer-basedcomposites. Nevertheless, insufficient interfacial interactions implicate the necessity of GTR modi-fication before introduction into polymer matrices....
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THE IMPACT OF GROUND TIRE RUBBER TREATMENT ON THE THERMAL CONDUCTIVITY OF FLEXIBLE POLYURETHANE/GROUND TIRE RUBBER COMPOSITES
PublicationWaste car tires are burdensome waste, and their utilization is crucial for the natural environment. In many countries, the primary method of their recycling is energy recovery, performed by simple combustion. However, material recycling is much more effective and significantly more beneficial for the natural environment. It results in the generation of ground tire rubber, which can be used to produce polymerrubber composites. It...
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Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer
PublicationThe physicochemical and mechanical properties of thin and freestanding heavy boron-doped diamond (BDD) nanosheets coated with a thin C:H:N:O plasma polymer were studied. First, diamond nanosheets were grown and doped with boron on a Ta substrate using the microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Next, the BDD/Ta samples were covered with nylon 6.6 to improve their stability in harsh environments and...
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THE INFLUENCE OF POLYMER STRIPS IN REDUCTION OF A STEEL GRANDSTAND VIBRATIONS
PublicationGrandstands are types of structures commonly used during sport events or music concerts. Dynamic loads generated by crowd movement may have significant influence on human perception as well as may lead to the destruction of a structure. Lighter and more slender structural steel members are more easily excitable by spectators. If the synchronized movement is tuned with the natural frequency of the affected part of the structure,...
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Effets de variabilite d'adhesion et de viellissement en collage structural
PublicationDivers essais peuvent etre employes afin d'evaluer la resistance a la fracture des joints adhesifes. Generalement, ces essais sont symetriques: les substrats sont identiques. Nous avons utilise une version asymetrique, ou un adherend flexible est colle a aderend rigide. Nous discutons ici du comportement d'un joint d'adhesion variable. Des resultats assez surprenants font le sujet prinicpal de cet article.
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Effect of ground tire rubber on structural, mechanical and thermal properties of flexible polyurethane foams
PublicationFlexible polyurethane foams were modified with two kinds of ground tire rubber, untreated and thermo-mechanically reclaimed. A reclamation process was performed in auto-thermal conditions, which reduced the cost of the process and decreased the environmental impact of devulcanization (e.g., emission of gases). The reclamation process was carried out in a continuous manner using a co-rotating twin screw extruder. The foams were...
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Recycled Polyurethane as a Second Phase in Thermoset Blends and Its Effect on Thermal Degradation Kinetics Studies
PublicationA new approach is introduced in the modification of thermosetting polymer by using different amount of polyurethane of waste origin. The post consumer polyurethane foam coatings are degraded using glycolysis process and the recycled product is further converted into new polyurethane. The blending of recycled polyurethane with epoxy exhibits transparency and produces nanostructures. The effective interaction between two polymers...
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pH-dependent composite coatings for controlled drug delivery system - Review
PublicationNowadays in case of long-term implants, the most common postoperative complications are bacterial infections, which in consequence may provoke loos- ening of the implants in the primary phase of stabilization. Bacterial infections are currently the most frequent cause of revision surgery of the implants such as hip joint endoprosthesis, knee joint endoprosthesis and dental implants. In order to provide the local and long-term antibacterial...
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Formation and Growth of the Crack in Bonded Joints Under Mode I Fracture: Substrate Deflection at Crack Vicinity
PublicationAdhesive bonding is now commonly used in aircraft, cars, boats, etc. In these applications, thin panels are often bonded. In such thin structures, heterogeneous mechanical loading along the bondline edge (or potential crack front), is likely to arise due to 3D structural effects. The crack front and its vicinity is a special region, in that it is where structural properties of the adherend material meet those of the adhesive (discontinuity)....
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublicationHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Polymeric Bearings as a new base isolation system suitable for mitigating machine-induced vibrations
PublicationThe present paper summarizes the preliminary results of the experimental shaking table investigation conducted in order to verify the effectiveness of a new base isolation system consisting of Polymeric Bearings in reducing strong horizontal machine-induced vibrations. Polymeric Bearing considered in the present study is a prototype base isolation system, which was constructed with the use of a specially prepared flexible polymer...
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Experimental and analytical analysis of punching shear in flat slabs supported on column topped with concrete head
PublicationAn experimental laboraatory test of the two series of slab-column elements topped with drop panels of varying sizes is described in this paper. The scope of the paper is to investigate the influence of the drop panel size and stiffness on the behaviour of the connection between the flat slab and the column topped by the concrete head. The impact of the head size and stiffness is analysed analytically and experimentally. The experimental...
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Influence of bitumen type on cracking resistance of asphalt mixtures used in pavement overlays
PublicationCracking is one of the predominant distresses occurring in flexible pavements, especially in old pavements that were rehabilitated with an asphalt overlay. In such cases asphalt mixtures should be designed to ensure high resistance to reflective cracking because new asphalt layers are exposed to existing cracks of the old pavement. The nature of these cracks can be various (transverse, longitudinal as well as crazy cracking). One...
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Preparation and characterization of porous scaffolds from chitosan-collagen-gelatin composite
PublicationNovel porous scaffolds composed of chitosan, collagen and gelatin were prepared and characterized. For preparing scaffolds gelatin and collagen isolated from fish skins with various physicochemical properties were used. In order to reduce preparation solubility glutaraldehyde in the amount of 1%, w/w relative to the total biopolymers weight in solution was used. All obtained biomaterials showed a homogeneous porosity. Protein polymer...
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POLYMER TESTING
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Effects of Noncontact Shoulder Tool Velocities on Friction Stir Joining of Polyamide 6 (PA6)
PublicationIn this study, the effects of the traverse and rotational velocities of the noncontact shoulder tool on the heat generation and heated flux during the friction stir joining of high-density polyamide 6 (PA6) polymer were investigated. The computational fluid dynamics (CFD) method was employed to simulate the thermomechanical phenomena during the friction stir joining (FSJ) process of PA6. A developed model was used to consider the...
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POLYMER
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Ecological Aspects of Polymer Package Recycling
e-Learning CoursesEcological Aspects of Polymer Package Recycling dr hab. inż. Justyna Kucińska-Lipka
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Investigation of low-temperature cracking in newly constructed high-modulus asphalt concrete base course of a motorway pavement
PublicationThe paper presents the issue of low-temperature transverse cracks which have developed in newly constructed base courses made of high-modulus asphalt concrete mix (HMAC). Numerous transverse cracks developed in the analysed HMAC base during the winter season before the pavement was actually completed, both at the transverse joint locations and in the areas between them. This had not happened so far on such a scale during road construction...
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POLYMER DEGRADATION AND STABILITY
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POLYMER BULLETIN
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Analysis of wave propagation in a bolted steel joint
PublicationThe paper presents results of numerical and experimental investigations of elastic wave propagation in a bolted single-lap joint. The research was carried out for both symmetric and antisymmetric Lamb wave modes. In experimental studies the PZT transducers were used to excite and register wave propagation signals. The controlled value of the torque during measurements was ensured by the use of high precision torque wrenches. Numerical...
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Rheology of polymer blends
PublicationPolymer blends are physical mixtures of two or more homopolymers or copolymers. This type of materials have wide spectrum of technological applications, and their properties are influenced, e.g., by the properties of single components and morphology of final material. The rheology of polymer blends is connected with the processing of polymer blends and is influenced by thermodynamics, morphology, and their evolution during testing....
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Smart Materials in Architecture: Useful Tools with Practical Applications or Fascinating Inventions for Experimental Design?
PublicationFor at least several decades smart or so-called intelligent materials, being the result of great advancements in material engineering, appear in architecture in different applications. Most of them are called "smart" because of their inherent properties: a real-time response to environmental stimuli. There are also those considered to be "smart" due to smart design: their original structure or the composition of their materials...
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3D Computer Model of the Hip Joint Cartilage
PublicationThis paper presents 3D computer model of the hip joint cartilage in the ANSYS program. Model is made on the basis of anatomy and collected data on the material constants of bone and cartilage components. Analysis and comparison of biochemical model, viscoelastic and molecular mixed - aggregation serves to facilitate the creation of the next model of reality, which could be used in the design of joint prostheses. The correctness...
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Study of the effect of thermally reduced graphene oxide on the physical and mechanical properties of flexible polyurethane foams
PublicationFlexible polyurethane foams were obtained from a two-component system via the one-step method. The foams were modified with thermally reduced graphene oxide added in the amount equal to 0.25, 0.5 and 0.75 wt%. The morphology, static and dynamic properties, and thermal stability of modified foams were determined. The application of carbon filler resulted in the visible increase in the cell size, apparent density and rigidity of...
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Polymer electrolytes with ionic liquids
PublicationSolid polymer electrolytes are solutions of salts in the macromolecular polymeric compound. Excellent process ability, flexibility, non-flammability and non-reactivity make them ideal materials for electrochemical devices. The problem in their use is limited conductivity. It increases with increasing salt concentration in the polymer, but at the same time the condition is to increase the glass transition temperature of the polymer...
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Medially positioned plate in first metatarsophalangeal joint arthrodesis
PublicationObjective The purpose of this study was to biomechanically compare the stability of first metatarsophalangeal (MTP1) joint arthrodesis with dorsally and medially positioned plates. Methods A physical model of the MTP1 joint consists of printed synthetic bones, a titanium locking plate and screws. In the experiments, samples with dorsally and medially positioned plates were subjected to loading of ground load character in a universal...
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Lamb wave propagation in a single lap adhesive joint
PublicationThe aim of the paper is the analysis of Lamb wave propagation in adhesive joints. The research was performed on a single lap adhesive joint of two steel plates. Two types of joints, namely an intact and with defect were considered. In experimental investigations the condition assessment of the joint was performed with the use of antisymmetric Lamb waves excited by a plate piezo actuators and measured by a laser vibrometer. Numeri-cal...
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Polymer Modified Bitumen
PublicationIn this paper we present the benefits of using polymers as an asphalt modifiers, especially the low molecular weight reactive compounds, which are capable of forming an polymer network with bitumen "in situ" in the process of its modification.
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Diagnostics of bolted lap joint using guided wave propagation
PublicationThe paper presents numerical and experimental analyses of elastic waves propagation in a bolted lap joint. In experimental investigations condition assessment of the joint was performed with the use of symmetric waves excited by a piezoactuator. Numerical calculations were conducted in commercial finite element method software Abaqus. The influence of number of bolts and the value of the initial stress on recorded signals was examined....
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Annals of Joint
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Flexible and Printed Electronics
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npj Flexible Electronics
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THE INFLUENCE OF MANUFACTURING OVERSIZING ON POSTWELDING DISTORTIONS OF THE FILLET WELDED JOINT
PublicationWelding proces is basic joining technique in shipbuilding. Such method generated welding distortions which cause a lot of problems during the manufacturing process. In the literature it is proposed wide spectrum of suggestions for a correct estimation of welding deformation in particular angular deformation in the fillet welded T joint. In the work influence of oversizing of weld on angular distortions of joint is presented basing...