| 1. |
- Argatov, Ivan, et al.
(författare)
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Axisymmetric JKR-type adhesive contact under equibiaxial stretching
- 2021
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Ingår i: The journal of adhesion. - : Taylor & Francis. - 0021-8464 .- 1563-518X .- 1545-5823. ; 97:2, s. 140-154
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Tidskriftsartikel (refereegranskat)abstract
- An axisymmetric frictionless adhesive contact problem for a spherical indenter pressed against an isotropic elastic incompressible half-space under equibiaxial stretching is studied in the framework of the generalized Johnson-Kendall-Roberts (JKR) theory, which accounts for the effect of weak coupling between fracture modes I and II by means of a phenomenological mode-mixity function. The model predicts that contact area can withstand a larger level of the substrate stretch under moderate pre-pulling force. We have provided simple formulas to evaluate the pull-off force and the critical contact radius at the detachment point.
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| 2. |
- Bastani, Alireza, et al.
(författare)
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Effect of open assembly time and equilibrium moisture content on the penetration of polyurethane adhesive into thermally modified wood
- 2017
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Ingår i: The journal of adhesion. - : Taylor & Francis. - 0021-8464 .- 1563-518X .- 1545-5823. ; 93:7, s. 575-583
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Tidskriftsartikel (refereegranskat)abstract
- The effect of wood moisture content and open assembly time on penetration of polyurethane (PU) adhesive into thermally treated Scots pine (195 and 210°C) was investigated according to effective (EP) and maximum penetration (MP) measurements using fluorescence microscopy. For samples treated at 195°C, a higher EP was noted at 8.6% equilibrium moisture content (EMC) after both assembly times (15 and 30 min) while for samples treated at 210°C, increasing wood moisture content resulted in a significant decrease in EP at 12.5% EMC after 15 min assembly time. Extending open assembly time was found to increase the EP of PU adhesive only in the case of samples treated at 195°C and with 8.6% EMC. For samples treated at both treatment temperatures and after shorter open assembly time, the highest MP observed at moderate EMC levels of 8.6 and 8.2% and the lowest at the higher EMC levels of 13.2 and 12.5%.
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| 3. |
- Berglin, Mattias, 1970, et al.
(författare)
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Use of surface-sensitive methods for the study of adsorption and cross-linking of marine bioadhesives
- 2005
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Ingår i: Journal of Adhesion. - : Informa UK Limited. - 0021-8464 .- 1563-518X .- 1545-5823. ; 81:7-8, s. 805-822
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Tidskriftsartikel (refereegranskat)abstract
- The establishment of the bond of sessile marine organisms such as barnacles, mussels, and algae in the marine environment starts with the secretion and the adsorption of the adhesive biopolymers to the substrate. Subsequently, this is followed by the formation of cohesive interactions with the next layer of adhesive biopolymers that are deposited/adsorbed on top of the first layer. These two fundamental processes for the adhesive plaque buildup have been subjected to several investigations in recent years using model molecules, especially Mefp-1 extracted from the blue mussel Mytilus edulis. With the introduction of optical surface-sensitive methods such as ellipsometry, surface plasmon resonance (SPR), and infrared spectroscopy (IR), it has been possible to elucidate both the kinetics of adsorption and structure of the Mefp-1 film. In contrast to adsorption, the cohesive interactions or the cross-linking are not easily followed with these optical methods and new approaches and techniques are required. One such technique that has been useful is the quartz-crystal microbalance with dissipation monitoring (QCM-D), which has been used for cross-linking studies of a variety of biopolymers including bioadhesives from mussel and algae. Copyright © Taylor & Francis Inc.
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| 4. |
- Carlberger, Thomas, et al.
(författare)
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Influence of Layer Thickness on Cohesive Properties of an Epoxy-Based Adhesive : An Experimental Study
- 2010
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Ingår i: The journal of adhesion. - : Taylor & Francis Group. - 0021-8464 .- 1563-518X .- 1545-5823. ; 86:8, s. 814-833
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Tidskriftsartikel (refereegranskat)abstract
- Cohesive laws are determined for different layer thicknesses of an engineering adhesive. The shape of the cohesive law depends on the adhesive layer thickness. Of the two parameters of the cohesive law—the fracture energy and thestrength—the fracture energy is more sensitive to thickness variation than the strength. The fracture energy in peel mode (Mode I) increases monotonically as the thickness is increased from 0.1 to about 1.0 mm. At an adhesive thickness of 1.5 mm, the fracture energy is slightly lower than for a 1.0 mm adhesive thickness, indicating a maximum between 1.0 and 1.5 mm. In shear mode (Mode II), the thickness dependence is not as strong, but an increasing trend in fracture energy with increasing adhesive thickness is evident. A slight decrease in strength with increasing adhesive thickness is found in both loading modes.
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| 5. |
- Fant, Camilla, et al.
(författare)
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Investigation of Adsorption and Cross-Linking of a Mussel Adhesive Protein Using Attenuated Total Internal Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR)
- 2010
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Ingår i: Journal of Adhesion. - : Informa UK Limited. - 0021-8464 .- 1545-5823 .- 1563-518X. ; 86:1, s. 25-38
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Tidskriftsartikel (refereegranskat)abstract
- Mytilus edulis foot protein 1 (Mefp-1) contains the redox-functional amino acid 3,4-dihydroxyphenylalanine (DOPA), which is a typical feature of most mefp proteins. We have previously shown, using combined optic (ellipsometry) and acoustic (QCM-D) measurements, that the oxidizing agent sodium periodate (NaIO4) and the transition metal ion Cu2+ promote cross-linking of Mefp-1. However, different chemical reaction mechanisms can not be distinguished using these methods. In the present study, we have complemented our previous investigations using Attenuated Total Internal Reflection Fourier Transform Infrared spectroscopy (ATR-FTIR), allowing a spectroscopic analysis of NaIO4 and Cu2+-induced cross-linking of Mefp-1 adsorbed on a ZnSe surface. In aqueous solution, adsorbed Mefp-1 displays absorption bands at 1570, 1472, 1260, and 973 cm(-1). Upon addition of NaIO4 and Cu2+, the absorptions at 1570, 1472, and 973 cm(-1) increase by approximately a factor of two. In contrast, the band at 1260 cm(-1) disappears upon cross-linking using NaIO4, but remains unchanged upon addition of Cu2+. This demonstrates that the band at 1260cm(-1) is attributed to the C O stretching vibration of the side chain hydroxyl groups in DOPA and that Cu2+ forms complexes with DOPA rather than transform it into an o-quinone. Moreover, upon addition of NaIO4 after cross-linking using Cu2+, the band at 1260cm(-1) disappears, indicating that the complex formation between DOPA and Cu2+ is reversed when DOPA is transformed into the o-quinone. These results demonstrate that NaIO4, which initiates a similar reaction to the naturally occurring enzyme catechol oxidase, contributes to the formation of di-DOPA cross-links. In contrast, the dominating contribution to the cross-linking from Cu2+, which is accumulated at high concentrations in the byssus thread of the blue mussel, is via complex formation between the metal and DOPA residues.
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| 6. |
- Islam, Md Shafiqul, 1984-, et al.
(författare)
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Peeling of metal foil from a compliant substrate
- 2021
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Ingår i: The journal of adhesion. - : Taylor & Francis. - 0021-8464 .- 1563-518X .- 1545-5823. ; 97:7, s. 672-703
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Tidskriftsartikel (refereegranskat)abstract
- Large displacement peel was studied for cases where a compliant substrate leads to a large value of the root rotation. An existing simplified beam model to calculate the peel fracture energy was modified to allow for a kinematic hardening beam model of the foil. The steady-state peel force and the root rotation were used as input data to the resulting analytical beam model. Test results from the literature were analysed. A more elaborate finite element model was also studied, using cohesive elements for the interface layer between the foil and the substrate. The cohesive zone parameters used were the fracture energy, the cohesive strength and a shape parameter. An optimization scheme for the cohesive zone parameters was developed and optimized against experimental steady-state peel force and root rotation. The optimization scheme was effective to characterize the cohesive parameters. The method yields similar values of fracture energy for the two peel angles, with the one for being slightly higher than for . The difference in fracture energies for different peel angles suggests that the fracture energy can be mode dependent.
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| 7. |
- Perepelkin, Nikolay V., et al.
(författare)
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Evaluation of elastic and adhesive properties of solids by depth-sensing indentation
- 2021
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Ingår i: The journal of adhesion. - : Taylor & Francis. - 0021-8464 .- 1563-518X .- 1545-5823. ; :6, s. 569-610
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Tidskriftsartikel (refereegranskat)abstract
- To describe properly interactions between contacting solids at micro/nanometre scales, one needs to know both adhesive and mechanical properties of the solids. Borodich and Galanov have introduced an effective method (the BG method) for identifying both characteristics from a single experiment on depth-sensing indentation by a spherical indenter using optimal fitting of the experimental data. Unlike traditional indentation techniques involving sharp indenters, the Borodich-Galanov methodology intrinsically takes adhesion into account. It is essentially a non-destructive approach. These features extend the scope of the method to important applications beyond the capabilities of conventional indentation. The scope of the original BG method was limited to the classic JKR and DMT theories. Recently, this restriction has been overcome by introducing the extended BG (eBG) method, where a new objective functional based on the concept of orthogonal distance curve fitting has been introduced. In the present work, questions related to theoretical development of the eBG method are discussed. Using the data for elastic bulk samples, it is shown that the eBG method is at least as good as the original BG method. It is shown that the eBG can be applied to adhesive indentation of coated, multilayered, functionally graded media.
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| 8. |
- Tserpes, K., et al.
(författare)
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A review on failure theories and simulation models for adhesive joints
- 2022
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Ingår i: The journal of adhesion. - : Bellwether Publishing, Ltd.. - 0021-8464 .- 1563-518X .- 1545-5823. ; 98:12, s. 1855-
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Tidskriftsartikel (refereegranskat)abstract
- In the framework of the Cost Action CERTBOND (Reliable roadmap for certification of bonded primary structures), a wide group of researchers from 27 European Countries have had the opportunity to work on the topic of certification of bonded joints for primary structural applications from different engineering sectors such as the aerospace, automotive, civil engineering, wind energy and marine sectors. Since virtual testing and optimization are basic tools in the certification process, one of the key objectives of CERTBOND is to critically review some of the available models and failure theories for adhesive joints. The present paper summarizes the outcome of this task. Nine different models/theories are described in detail. Specifically, reviewed are the Classical Analytical Methods, the Process Zone Methods, Linear Elastic Fracture Mechanics (LEFM), the Virtual Crack Closure Technique (VCCT), the Stress Singularity Approach, Finite Fracture Mechanics (FFM), the Cohesive Zone Method (CZM), the Progressive Damage Modeling method and the Probabilistic methods. Also, at the end of the paper, the modeling of temperature effects on adhesive joints have been addressed. For each model/theory, information on the methodology, the required input, the main results, the advantages and disadvantages and the applications are given. © 2021 The Author(s).
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| 9. |
- Jönsson, Bo, et al.
(författare)
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Ion-ion correlations in liquid dispersions
- 2004
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Ingår i: Journal of Adhesion. - : Informa UK Limited. - 0021-8464. ; 80:5, s. 339-364
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Tidskriftsartikel (refereegranskat)abstract
- Ion-ion correlations play an important role in liquid dispersion with, strong eleetrostatic inlet-actions. Examples can be found in very diverse areas with the setting of cement paste as one extreme and the compactation, of DNA as another. One particularly spectacular effect of ion-ion correlations is that the traditional double layer repulsion sometimes can be converted into a net attraction. This typically takes place in the presence of multivalent counterions and/or in solutions with low dielectric permittivity. The attractive forces are driven by the energy while the repulsive are mainly of entropic origin, and the final outcome is a delicate balance of these contributions. Here we present two simple models, which give a conceptually simple description of this balance.
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