scholarly journals Effect of nylon fabric reinforcement on the mechanical performance of adhesive joints made between glass and GFRP

2021 ◽  
Vol 16 (59) ◽  
pp. 89-104
Author(s):  
Placido Munafò ◽  
Francesco Marchione ◽  
Gianluca Chiappini ◽  
Monica Marchini
Keyword(s):  
Mechanical Performance ◽  
Joint Stiffness ◽  
Adhesive Layer ◽  
Tensile Tests ◽  
Nylon 6 ◽  
Float Glass ◽  
Adhesive Joints ◽  
Fabric Reinforcement ◽  
Reinforcement System ◽  
Nylon Fabric

The use of reinforcements in adhesive joints makes the stress distribution more uniform, improving their mechanical performance and adhesion. The present paper aims to verify the effectiveness and efficiency of the insertion of nylon 6 fabric in the adhesive layer, to study their applicability and functionality in building components. The increase in stiffness achieved by applying nylon 6 fabric in the adhesive layer between glass and GFRP pultruded profiles and steel laminates applied to GFRP beams is investigated. Three different epoxy adhesives and one epoxy resin are used and compared. Three different types of tests are carried out in order to study the different properties of the reinforcement system: tensile tests on GFRP/GFRP single-lap adhesive joints, with and without nylon fabric reinforcement; tensile tests on double-lap adhesive joints between float glass and pultruded GFRP profiles reinforced with nylon fabric according to four configurations (in the middle plane of the adhesive layer, on the glass surfaces, on the GFRP surfaces, on both GFRP and glass configurations) to verify the influence of its position; three-point bending tests on long GFRP tubular profiles reinforced with steel plates and nylon fabric in different configurations, to study resistance to bending loads. The results from the experimental campaign show the effectiveness of the reinforcement system using nylon fabric 6. In general, both a reduction in ultimate strength and an increase in joint stiffness compared to unreinforced configurations are observed.

scholarly journals The Mechanical Performance of Re-Bonded and Healed Adhesive Joints Activable through Induction Heating Systems

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6351
Author(s):  
Raffaele Ciardiello
Keyword(s):  
Mechanical Properties ◽  
Electromagnetic Field ◽  
Induction Heating ◽  
Mechanical Performance ◽  
Joint Stiffness ◽  
Fatigue Tests ◽  
Adhesive Joints ◽  
Lap Joint ◽  
Heating Systems ◽  
Maximum Shear Strength

This work aims to study the healing potential properties of a reversible thermoplastic adhesive. The adhesive is activable by using induction heating systems that can induce thermal heat in the particles throughout the electromagnetic field so they can melt the adhesive for bonding or separation procedures. The healing procedure consists of damaging single lap joint (SLJ) specimens with quasi-static and fatigue tests and then using an inductor to generate an electromagnetic field able to heat the adhesive to its melting point in order to heal the damaged SLJ specimens. SLJ tests were performed on damaged and healed specimens to assess, respectively, the residual mechanical properties of the damaged specimens and the mechanical properties after healing. SLJ tests showed that the healing procedure can completely recover the joint stiffness of the damaged adhesive joints, a huge part of the maximum shear strength and the SLJ absorbed energy. This work shows also the possibility of re-bonding completely failed or separated SLJs by using the same procedure. The mechanical properties of SLJs after healing and re-bonding are compared to the SLJ compared on virgin specimens to assess the recovered mechanical properties.

Bond Thickness Effects upon Dynamic Behaviour in Adhesive Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3920-3923 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Behaviour ◽  
Adhesive Layer ◽  
Adhesive Joints ◽  
Response Functions ◽  
Frequency Range ◽  
Element Analysis ◽  
Cantilevered Beam ◽  
Different Thickness

The influence of adhesive layer thickness on the dynamic behaviour of the single-lap adhesive joints is investigated in this paper. The ABAQUS finite element analysis (FEA) software was used to predict the frequency response functions (FRFs) of the single-lap adhesive joints of different thickness of the adhesive layer. As a reference, the FRFs of a cantilevered beam without joint were investigated as well. It is clear that the FRFs of the four beams are close to each other within the frequency range 0~1000 Hz. It is also found that the composite damping of the single-lap adhesive joint increases as the thickness of the adhesive layer increases.

scholarly journals Wastes from Agricultural Silage Film Recycling Line as a Potential Polymer Materials

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1383
Author(s):  
Jerzy Korol ◽  
Aleksander Hejna ◽  
Klaudiusz Wypiór ◽  
Krzysztof Mijalski ◽  
Ewelina Chmielnicka
Keyword(s):  
Vinyl Acetate ◽  
Thermal Performance ◽  
Mechanical Performance ◽  
Ethylene Vinyl Acetate ◽  
Tensile Tests ◽  
Solid Particles ◽  
Polymer Materials ◽  
Slight Reduction ◽  
Scanning Calorimetry ◽  
Crystallinity Degree

The recycling of plastics is currently one of the most significant industrial challenges. Due to the enormous amounts of plastic wastes generated by various industry branches, it is essential to look for potential methods for their utilization. In the presented work, we investigated the recycling potential of wastes originated from the agricultural films recycling line. Their structure and properties were analyzed, and they were modified with 2.5 wt % of commercially available compatibilizers. The mechanical and thermal performance of modified wastes were evaluated by tensile tests, thermogravimetric analysis, and differential scanning calorimetry. It was found that incorporation of such a small amount of modifiers may overcome the drawbacks caused by the presence of impurities. The incorporation of maleic anhydride-grafted compounds enhanced the tensile strength of wastes by 13–25%. The use of more ductile compatibilizers—ethylene-vinyl acetate and paraffin increased the elongation at break by 55–64%. The presence of compatibilizers also reduced the stiffness of materials resulting from the presence of solid particles. It was particularly emphasized for styrene-ethylene-butadiene-styrene and ethylene-vinyl acetate copolymers, which caused up to a 20% drop of Young’s modulus. Such effects may facilitate the further applications of analyzed wastes, e.g., in polymer film production. Thermal performance was only slightly affected by compatibilization. It caused a slight reduction in polyethylene melting temperatures (up to 2.8 °C) and crystallinity degree (up to 16%). For more contaminated materials, the addition of compatibilizers caused a minor reduction in the decomposition onset (up to 6 °C). At the same time, for the waste after three washing cycles, thermal stability was improved. Moreover, depending on the desired properties and application, materials do not have to go through the whole recycling line, simplifying the process, reducing energy and water consumption. The presented results indicate that it is possible to efficiently use the materials, which do not have to undergo the whole recycling process. Despite the presence of impurities, they could be applied in the manufacturing of products which do not require exceptional mechanical performance.

scholarly journals Chemical and physical interactions of regenerated cellulose yarns and isocyanate-based matrix systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bernhard Ungerer ◽  
Ulrich Müller ◽  
Antje Potthast ◽  
Enrique Herrero Acero ◽  
Stefan Veigel
Keyword(s):  
Mechanical Performance ◽  
Tensile Force ◽  
Tensile Modulus ◽  
Tensile Tests ◽  
Size Exclusion ◽  
Regenerated Cellulose ◽  
Hydrolytic Cleavage ◽  
Yarn Twist ◽  
Exclusion Chromatography ◽  
Physical And Chemical

AbstractIn the development of structural composites based on regenerated cellulose filaments, the physical and chemical interactions at the fibre-matrix interphase need to be fully understood. In the present study, continuous yarns and filaments of viscose (rayon) were treated with either polymeric diphenylmethane diisocyanate (pMDI) or a pMDI-based hardener for polyurethane resins. The effect of isocyanate treatment on mechanical yarn properties was evaluated in tensile tests. A significant decrease in tensile modulus, tensile force and elongation at break was found for treated samples. As revealed by size exclusion chromatography, isocyanate treatment resulted in a significantly reduced molecular weight of cellulose, presumably owing to hydrolytic cleavage caused by hydrochloric acid occurring as an impurity in pMDI. Yarn twist, fibre moisture content and, most significantly, the chemical composition of the isocyanate matrix were identified as critical process parameters strongly affecting the extent of reduction in mechanical performance. To cope with the problem of degradative reactions an additional step using calcium carbonate to trap hydrogen ions is proposed.

scholarly journals Mechanical Optimization of Concrete with Recycled PET Fibres Based on a Statistical-Experimental Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 240
Author(s):  
Alejandro Meza ◽  
Pablo Pujadas ◽  
Laura Montserrat Meza ◽  
Francesc Pardo-Bosch ◽  
Rubén D. López-Carreño
Keyword(s):  
Reinforced Concrete ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Superior Performance ◽  
Fibre Reinforced Concrete ◽  
Marine Fauna ◽  
Recycled Pet ◽  
Pet Bottles ◽  
Fibre Aspect Ratio

Discarded polyethylene terephthalate (PET) bottles have damaged our ecosystem. Problems of marine fauna conservation and land fertility have been related to the disposal of these materials. Recycled fibre is an opportunity to reduce the levels of waste in the world and increase the mechanical performance of the concrete. PET as concrete reinforcement has demonstrated ductility and post-cracking strength. However, its performance could be optimized. This study considers a statistical-experimental analysis to evaluate recycled PET fibre reinforced concrete with various fibre dose and aspect ratio. 120 samples were experimented under workability, compressive, flexural, and splitting tensile tests. The results pointed out that the fibre dose has more influence on the responses than its fibre aspect ratio, with statistical relation on the tensional toughness, equivalent flexural strength ratio, volumetric weight, and the number of fibres. Moreover, the fibre aspect ratio has a statistical impact on the tensional toughness. In general, the data indicates that the optimal recycled PET fibre reinforced concrete generates a superior performance than control samples, with an improvement similar to those reinforced with virgin fibres.

scholarly journals Mechanical and thermal stability of retained austenite in plastically deformed bainite-based TRIP-aided medium-Mn steels

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Cost Effective ◽  
Tensile Tests ◽  
Thermal Stability Of

AbstractAdvanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.

NON-DESTRUCTIVE EVALUATION OF MECHANICAL DAMAGE OF ADHESIVES USING MAGNETO-ELECTRIC NANOPARTICLES

2021 ◽  
Author(s):  
GONZALO SEISDEDOS ◽  
BRIAN HERNANDEZ ◽  
JULIETTE DUBON ◽  
MARIANA ONTIVEROS ◽  
BENJAMIN BOESL ◽  
...  
Keyword(s):  
Adhesive Joint ◽  
Adhesive Bonding ◽  
Mechanical Damage ◽  
Adhesive Bond ◽  
Tensile Tests ◽  
Adhesive Joints ◽  
Adhesive Bonds ◽  
Magnetic Signatures ◽  
Looper System ◽  
Lock In

Adhesive bonding has been shown to successfully address some of the main problems with traditional fasteners, such as the reduction of the overall weight and a more uniformly distributed stress state. However, due to the unpredictability of failure of adhesive bonds, their use is not widely accepted in the aerospace industry. Unlike traditional fastening methods, it is difficult to inspect the health of an adhesive joint once it has been cured. For adhesive bonding to be widely accepted and implemented, there must be a better understanding of the fracture mechanism of the adhesive joints, as well as a way to monitor the health of the bonds nondestructively. Therefore, in-field structural health monitoring is an important tool to ensure optimal condition of the bond is present during its lifetime. This project focuses on the advancement of a non-invasive field instrument for evaluation of the health of the adhesive joints. The tool developed is based on a B-H looper system where coils are arranged into a noise-cancellation configuration to measure the magnetic susceptibility of the samples with a lock-in amplifier. The B-H looper system can evaluate the state of damage in an adhesive bond by detecting changes in surface charge density at the molecular level of an epoxy-based adhesive doped with magneto-electric nanoparticles (MENs). Epoxy-based adhesive samples were doped with MENs and then scanned using the B-H looper system. To evaluate the health of the adhesive joint, microindentation and tensile tests were performed on MENs-doped adhesive samples to understand the relationship between mechanical damage and magnetic signal. Correlations between magnetic signatures and mechanical damage were minimally observed, thus future studies will focus on refining the procedure and damaging methodology.

Performance of All-Polypropylene Composites at LNG Temperatures

2017 ◽  
Author(s):  
Bilim Atli-Veltin
Keyword(s):  
Composite Materials ◽  
Mechanical Performance ◽  
Cost Effective ◽  
Tensile Tests ◽  
Small Scale ◽  
Failure Behavior ◽  
Polypropylene Composites ◽  
Design Flexibility ◽  
Static Tensile ◽  
Interlaminar Shear

In the small scale LNG infrastructure, composite materials are scarcely employed. Potentially, cost effective solutions for LNG applications could be developed thanks to the advantages of composite materials over metals such as weight savings, design flexibility and recyclability. The research presented in this paper focuses on the mechanical performance of fully recyclable, thermoplastic Polypropylene (PP) composite tapes at cryogenic LNG temperatures. Quasi-static tensile tests performed on [±45] laminates made of plain woven plies of PURE® show that at −196°C the behavior is bilinear with the failure strain of 6.5% and failure stress of 37 MPa. Such non-brittle failure behavior of PP is desirable for cryogenic applications. The other results presented in the paper contains [0/90] laminate results and the interlaminar shear strength characteristics at room and cryogenic temperatures.

Sign in / Sign up

Export Citation Format

Share Document