The Experts below are selected from a list of 1620 Experts worldwide ranked by ideXlab platform
Qiao Hai - One of the best experts on this subject based on the ideXlab platform.
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Influence of cure temperature on performance of SY-H2 Adhesive
Journal of Aeronautical Materials, 2002Co-Authors: Qiao HaiAbstract:An experimental study was undertaken to determine the effects of cure temperature on shear strength of SY H2 Paste Adhesive.Firstly,curing reaction kinetics of SY H2 Paste Adhesive was researched by differential scanning Calorimeter(DSC).According to Kissinger and Ozawa method,the apparent activation energy of curing reactions was determined to be 102 3kJ/mol and 103 9kJ/mol respectively.Kinetic order of curing reactions calculated according to Crane method was 0 943.Furthermore,correlation of scanning rate Φ with peak temperature T p from DSC data was found that Tp and lnΦagree with linear relation.Finally,influence of cure temperature on shear strength of SY H2 Paste Adhesive was discussed.Increase of cure temperature in a given time can improve the bonding strength.Optimal curing parameter was suggested to be from 130℃to 140℃for two hours.
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Study on properties of SY-H1 Paste Adhesive
Journal of Aeronautical Materials, 2002Co-Authors: Qiao HaiAbstract:SYH1 is a medium temperature curing onecomponent Paste epoxy Adhesive.Properties of SYH1 Adhesive such as curing process conditions,water resistance,thermal aging,temperature alternate cycles,room temperature storage,hotwet aging and fatigue are introduced in detail.SYH1 Adhesive has the characteristics of lower curing temperature,higher temperature resistance and also longer room temperature storage life.It can be used in bonding of steel,aluminum and composite.
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Study on Properties of SY-H2 Medium Temperature Curing Paste Adhesive
Journal of Materials Engineering, 2002Co-Authors: Qiao HaiAbstract:SY H2 is a kind of medium temperature curing one component Paste Adhesive.Properties of SY H2 Adhesive such as shear strength,peel strength,water resistance,thermal aging,low temperature resistance,fatigue and creep are introduced in detail.
Markus Zogg - One of the best experts on this subject based on the ideXlab platform.
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acceleration of the curing process of a Paste Adhesive for aerospace applications considering cure dependent void formations
International Journal of Adhesion and Adhesives, 2014Co-Authors: Sanchez A Cebrian, Florian Klunker, Ralph Basler, Markus ZoggAbstract:In this publication, the acceleration of the curing process of a Paste Adhesive used for bonding aerospace components is investigated. Previous investigations have proven that the use of high temperatures not only reduces the curing time but also increases the void formation. This phenomenon takes place due to evaporation of volatiles at high temperatures and affects the mechanical performance of the bonded joint. In this study a dual step cure process is investigated, where the curing temperature is increased depending on the degree of cure of the Paste Adhesive. In this context, the impact of increasing the temperature at different stages of the curing reaction is analyzed, determining a strategy to accelerate the curing reaction without major void formation. By this approach, the curing time of the Paste Adhesive used for this investigation could be reduced from 4 h to 30 min without decreasing the mechanical performance of the bonded joint.
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Modeling of void formation during the curing process of Paste Adhesives
Journal of Adhesion Science and Technology, 2013Co-Authors: A. Sánchez Cebrián, Florian Klunker, Markus ZoggAbstract:In this study, the void formation of the Paste Adhesives used for bonding of aerospace components is investigated. When high temperatures are applied to accelerate the curing process, volatiles evaporate; therefore the mechanical performance of joints is affected as a result of an increased void content. Today, mass reduction models only consider the degradation of fully cured samples, not taking into account the influence of the curing process on the quality of the Paste Adhesive. The fundamental idea of this paper is that the amount of mass reduction as a result of evaporation of the Paste Adhesive decreases with higher curing progression. For quantification, a model is defined approximating the mass reduction in a Paste Adhesive as a function of temperature, time and the degree of cure. Thermo gravimetric analysis is used to obtain the experimental data of the evaporation process for curing cycles with a single dwell at different temperatures applied to the Paste Adhesive. These data are used to define...
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Simulation of the cure of Paste Adhesives by induction heating
Journal of Composite Materials, 2013Co-Authors: A. Sanchez Cebrian, Florian Klunker, Markus ZoggAbstract:This study, part of the European JTI 'Clean sky', presents a simulation model designed to predict the evolution of the degree of cure of the Paste Adhesives used in carbon fiber reinforced polymer bonded systems cured by induction heating. The simulation combines induced Eddy currents in electrical conductive materials, which cause the heating of the carbon fiber reinforced polymer adherents by Joule effect, and the consequent chemical reaction which gives the relation between temperature, time and degree of cure of the Adhesive. The model is validated and used to analyze the impact of different parameters on the degree of cure of the Paste Adhesive.
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Methodology for optimization of the curing cycle of Paste Adhesives
International Journal of Adhesion and Adhesives, 2013Co-Authors: A. Sánchez Cebrián, Markus Zogg, Paolo ErmanniAbstract:This contribution, carried out in the frame of the European Joint Technology Initiative ‘Clean Sky’, presents the results of a research program investigating the influence of fast curing on the quality of epoxy based Paste Adhesives. Today, the curing of Paste Adhesives is typically carried out following the supplier's recommendations. In order to reduce cycle time, save costs and energy resources, Paste Adhesives could be cured at higher temperature. To ensure a bonded joint quality with maximum mechanical performance, the limitation of this temperature increase is studied. This study shows the effects of the use of high temperatures in the curing process, which can lead to a degradation of the Adhesive system due to the increase of void content, decreasing the mechanical performance in the Paste Adhesive as well as in the bonded joint. The goal of this research is to find fast and robust processing of Paste Adhesives and to develop a methodology to determine the maximum curing temperature possible. Different properties of the Adhesive are investigated, including different thermal analysis techniques, optical and mechanical testing of the pure Adhesive. Additionally, state of the art qualification of Paste Adhesives, single lap shear testing, is considered. In this study, a novel method to control the quality of the cured Paste Adhesives is defined based on the analysis of the pure cured Paste Adhesive, not influenced by the adherent quality, by measuring the void content and its effects on the bonded joint.
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Paste Adhesive modification for induction curing
2012Co-Authors: Alberto Sánchez Cebrián, Markus Zogg, Patrick Moser, Paolo ErmanniAbstract:This contribution, carried out in the frame of the European JTI ‘Clean Sky’, is presenting the results of a research program investigating the curing of Paste Adhesives by induction heating. The goal is to modify the Paste Adhesive to be able to heat it by induction, having the possibility to bond non-electrical conductive composites structures e.g. Glass fiber reinforced polymers (GFRP). Additionally, the possibility to accelerate the curing process of Adhesives used to bond conductive composites, e.g. carbon fiber reinforced polymers (CFRP), and its effects on the mechanical performance are investigated. Different fillers, made of electrical conductive and ferromagnetic materials, are mixed with the Paste Adhesive and then cured by induction. Then, the temperature generated in the modified Paste Adhesive is measured. Samples of composite bonded systems are mechanically tested to observe the effects of the particles on the mechanical performance of the joint and assess to the potential of bonding of CFRP and GFRP structures by induction heating.
Paolo Ermanni - One of the best experts on this subject based on the ideXlab platform.
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Methodology for optimization of the curing cycle of Paste Adhesives
International Journal of Adhesion and Adhesives, 2013Co-Authors: A. Sánchez Cebrián, Markus Zogg, Paolo ErmanniAbstract:This contribution, carried out in the frame of the European Joint Technology Initiative ‘Clean Sky’, presents the results of a research program investigating the influence of fast curing on the quality of epoxy based Paste Adhesives. Today, the curing of Paste Adhesives is typically carried out following the supplier's recommendations. In order to reduce cycle time, save costs and energy resources, Paste Adhesives could be cured at higher temperature. To ensure a bonded joint quality with maximum mechanical performance, the limitation of this temperature increase is studied. This study shows the effects of the use of high temperatures in the curing process, which can lead to a degradation of the Adhesive system due to the increase of void content, decreasing the mechanical performance in the Paste Adhesive as well as in the bonded joint. The goal of this research is to find fast and robust processing of Paste Adhesives and to develop a methodology to determine the maximum curing temperature possible. Different properties of the Adhesive are investigated, including different thermal analysis techniques, optical and mechanical testing of the pure Adhesive. Additionally, state of the art qualification of Paste Adhesives, single lap shear testing, is considered. In this study, a novel method to control the quality of the cured Paste Adhesives is defined based on the analysis of the pure cured Paste Adhesive, not influenced by the adherent quality, by measuring the void content and its effects on the bonded joint.
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Paste Adhesive modification for induction curing
2012Co-Authors: Alberto Sánchez Cebrián, Markus Zogg, Patrick Moser, Paolo ErmanniAbstract:This contribution, carried out in the frame of the European JTI ‘Clean Sky’, is presenting the results of a research program investigating the curing of Paste Adhesives by induction heating. The goal is to modify the Paste Adhesive to be able to heat it by induction, having the possibility to bond non-electrical conductive composites structures e.g. Glass fiber reinforced polymers (GFRP). Additionally, the possibility to accelerate the curing process of Adhesives used to bond conductive composites, e.g. carbon fiber reinforced polymers (CFRP), and its effects on the mechanical performance are investigated. Different fillers, made of electrical conductive and ferromagnetic materials, are mixed with the Paste Adhesive and then cured by induction. Then, the temperature generated in the modified Paste Adhesive is measured. Samples of composite bonded systems are mechanically tested to observe the effects of the particles on the mechanical performance of the joint and assess to the potential of bonding of CFRP and GFRP structures by induction heating.
Salih Akpinar - One of the best experts on this subject based on the ideXlab platform.
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Effects of unbalance on the Adhesively bonded composites-aluminium joints
The Journal of Adhesion, 2016Co-Authors: KürŞat Gültekin, Salih Akpinar, Adnan Özel, GülŞah Alar ÖnerAbstract:ABSTRACTThis article presents the experimental and numerical results of Adhesively bonded hybrid single-lap joint (SLJ) geometry with different configurations of lower and upper adherends subject to a four-point bending test. AA2024-T3 aluminium alloy and carbon/epoxy composites with different lamina numbers and four different stacking angles as adherend and two-part liquid, structural Adhesive DP 125 as Paste Adhesive were used. In the experimental studies, three different types of SLJs were produced using lower material that had a constant thickness of AA2024-T3 aluminium alloy and upper material of composite material that had different numbers of layers and four different stacking sequences ([0], [0/90], [45/−45], [0/45/−45/90]). In the numerical analysis, stress analyses of the SLJs were performed with a three-dimensional non-linear finite element method and the composite adherends were assumed to behave as linearly elastic materials, while the Adhesive and aluminium adherend were assumed to be non-li...
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The effect of the adherend width on the strength of Adhesively bonded single-lap joint: Experimental and numerical analysis
Composites Part B: Engineering, 2014Co-Authors: KürŞat Gültekin, Salih Akpinar, Adnan ÖzelAbstract:In the present study, mechanical properties of different Single Lap Joint (SLJ) configurations with different adherent width values subjected to tensile loading were investigated experimentally and numerically. Using AA2024-T3 aluminum alloy as adherend and DP460 as Paste Adhesive, eight different types of single-lap joint samples (width of the adherent was 5, 10, 15, 20 or 25 m; overlap length was 5 ,10, 15, 20 or 25 mm) were produced for experimental studies. Stress analyses in the SLJ were performed non-linear finite element method by considering the geometrical non-linearity and the material non-linearities of the Adhesive (DP460) and adherend (AA2024-T3). As a result, in SLJ geometries, increasing the adherent width raises the load-carrying capacity of the joints higher when compared to increasing overlap length. The failure load value of the joint increases as the area of bonding varies from rectangle to square. In addition, it was found that the data obtained from finite element analysis were coherent with experimental results.
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The effect of the spew fillet on an Adhesively bonded single-lap joint subjected to bending moment
Composites Part B-engineering, 2013Co-Authors: Salih Akpinar, Muhammet Onur Doru, Adnan Özel, Murat Demir Aydin, Hamed Ghaffarzadeh JahanpasandAbstract:The mechanical behaviors of an Adhesively bonded single lap joint with a spew fillet under bending moment, where the widths of the upper-adherend and lower-adherend are not the same, were studied experimentally and numerically. Using AA2024-T3 aluminum alloy as adherend and DP460 as Paste Adhesive, four different types of single-lap joint samples (without spew fillet, with spew fillet at joint edges, with spew fillet at joint ends and with spew fillet at all edges) were produced for experimental studies. Stress analyses in the single-lap joint were performed with a three dimensional non-linear finite element method by considering the geometrical non-linearity and non-linear material behaviors of both Adhesives (DP460) and adherend (AA2024-T3). The single lap joint with the spew fillet with different widths had a significant effect on the stress distribution. Additionally, the spew fillet increased the load carrying capacity of the joint and decreased the stress concentration of the joint.
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Effect of the Spew Fillet on Adhesively Bonded Single-Lap Joint Subjected to Tensile Loading: Experimental and 3-D Non-Linear Stress Analysis
Journal of Adhesion, 2013Co-Authors: Muhammet Onur Doru, Salih Akpinar, Adnan Özel, Murat Demir AydinAbstract:In the single-lap joint (SLJ) geometry, peel stresses occur at the overlap ends due to load eccentricity and the presence of shear-free Adhesive termination surfaces. These peel stresses, along with the transverse tensile stresses which occur along the overlap longitudinal axes, and Adhesive shear stresses, ultimately cause joint failure. Obviously, reductions in these stresses should result in higher joint strength and increased load capacity. In the present study, the mechanical behavior of the SLJ geometry of various widths having spew fillets, which was subjected to tensile loading, were investigated experimentally and numerically. For this purpose, firstly, four different types of SLJ samples (without spew fillet, with spew fillet at joint edges, with spew fillet at joint ends, and with spew fillet at all edges) were produced for experimental studies by using two-part Paste Adhesive. Then, stress analyses in the SLJ were performed with a three-dimensional non-linear finite element method by consideri...
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Effects of laminate carbon/epoxy composite patches on the strength of double-strap Adhesive joints: Experimental and numerical analysis
Materials & Design, 2013Co-Authors: Salih AkpinarAbstract:Abstract In this study, mechanical properties of double-strap joints with aluminum or composite patches of different orientation angles at their overlap area were investigated under tensile loading. For this purpose, AA2024-T3 aluminum was used as adherend, while patches were either AA2024-T3 aluminum or 16-ply laminate of carbon/epoxy composite with five different orientation angles ([0] 16 , [90] 16 , [0/90] 8 , [45/−45] 8 , [0/45/−45/90] 4 ). A two-part Paste Adhesive (DP 460) was used to bond adherend and patches. Six different types of joint samples were subjected to tensile loading. The effect of patch material on failure load and stress distribution was examined experimentally and numerically. As a result, it was concluded that the data obtained from 3-D finite element analysis were coherent with experimental results and additional to that fiber orientation angles of the patches markedly affected the failure load of joints, failure mode and stress distributions appeared in Adhesive and composite.
J A Poulis - One of the best experts on this subject based on the ideXlab platform.
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susceptor assisted induction curing behaviour of a two component epoxy Paste Adhesive for aerospace applications
International Journal of Adhesion and Adhesives, 2017Co-Authors: C Severijns, Teixeira S De Freitas, J A PoulisAbstract:Abstract The curing behaviour and the mechanical behaviour of susceptor-assisted induction-cured Adhesively bonded joints has been investigated. Induction Heating (IH) was established by mixing Iron particles into a two component epoxy Paste Adhesive. The effect of different process parameters, such as particle content, coupling distance and coil current, on the IH curing process was evaluated by experimental tests and simulation of the induction heating process in COMSOL multiphysics. The process simulation showed that hysteresis losses has a major contribution for the heat generation of IH using Iron particles. Differential scanning calorimetry (DSC) analysis was used to assess the effect of susceptor particles on the cure behaviour of the Adhesive. The results showed that the Iron particles do not interfere with the curing process of the epoxy Adhesive in scope. The mechanical performance was evaluated through Single Lap-Shear (SLS) testing at different volume-percentages of Iron particles in combination with glass fibre reinforced plastic (GFRP) adherends. Induction-cured SLS samples were compared with conventional oven-cured SLS samples. In the oven cured samples, the addition of Iron particles resulted in a decrease in the lap-shear strength of 15% to 20%, even for a volume-percentage as low as 0.5%. An additional increase in particle content up to 7.5 v% did not show any additional reduction in the lap-shear strength. Furthermore, results show that when curing the Adhesive layer from the inside, as in the susceptor-assisted induction heating, the lap-shear strength is 6% higher than in oven-cured samples (curing the Adhesive layer from the outside).