Numerical analysis of the adhesive forces in nano-scale structure

Cho, Young‐Sam; Han, Houkseop; Kim, Wan-Doo

doi:10.1016/s1672-6529(07)60004-3

Cited by 10 publications

(9 citation statements)

References 10 publications

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“…For two macroscopic phases, 1 and 2, which interact across a medium 3, A can be estimated based on the optical and electric properties of a material using McLachlan's equation [15]: A kT n n n n h n n n n n n n n (5) where the input parameters are the dielectric constants  ( ) and the refractive indices (n), and e  is the absorption frequency. For two dissimilar materials, the Hamaker constant may be estimated in terms of the geometric mean of the Hamaker constant of each material [16], that is: 12 11 22…”

Section: Adhesion Forces and Hamaker Expressionsmentioning

confidence: 99%

“…This parameter is presented in Eq. (9), where depth h is the penetration depth, L real is the real area of contact, 12 A is the Hamaker constant, E is the elastic modulus, and failure  is the material stress strength. This parameter is analogous to Archard's equation [28], since it relates mechanical properties and system characteristics to evaluate wear, but is dedicated to the analysis of adhesion and, for now, is restricted to the nanoscale.…”

Section: Adhesive Wear and Materials Transfermentioning

confidence: 99%

“…The first can be estimated by two major parameters-the junctionbreaking shear stress and the junction size-which can be obtained by analyzing the elastic continuum adhesive contact, such as the Johnson-Kendall-Roberts (JKR) [7], Derjaguin-Muller-Toporov (DMT) [8], and Maugis-Dugdale (MD) [9] theories, or by finite element adhesive contact models [10,11,12]. These analyses [712] can also predict the pull-off force, contact force, and contact area [13].…”

Section: Introductionmentioning

confidence: 99%

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Numerical modeling of adhesion and adhesive failure during unidirectional contact between metallic surfaces

et al. 2016

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Abstract:In this work, we developed a finite element modeling approach to study adhesion during unidirectional contact between a two-dimensional plane-strain square and a flat slab. The surfaces were metallic or ceramic, and we analyzed different pairs of materials and their adhesion intensity using a FORTRAN subroutine (DLOAD) connected to a commercial finite element code Abaqus, which provided the surface attractive forces based on the Lennard-Jones interatomic potential using Hamaker constants. We considered adhesive loads during both the approach and separation of the surfaces. During the separation step, we modeled the material transfer between surfaces due to adhesion with respect to damage initiation and propagation at the flat slab. The parameters considered in the simulations include normal load, chemical affinity, and system size, and we analyzed different conditions by comparing the interaction forces during approach and withdrawal. This work also presents: (i) a description of the evolution of energy dissipation due to adhesion hysteresis, (ii) the formation-growth-breakage process of the adhesive junctions and the material transfer between surfaces, and (iii) an adhesive wear map based on a proposed novel equation that correlates the material parameters and material loss due to adhesion. The results indicate that the chemical affinity between bodies in contact is more related to adhesion than the applied load. In addition, the ratio between the material strength and elastic modulus seems to be an important factor in reducing adhesive wear.

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Section: Adhesion Forces and Hamaker Expressionsmentioning

confidence: 99%

Section: Adhesive Wear and Materials Transfermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Numerical modeling of adhesion and adhesive failure during unidirectional contact between metallic surfaces

et al. 2016

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“…For this purpose, researchers have been investigating the adhesion mechanisms used in nature by certain animals and insects. [7][8][9][10] For instance, it is found that geckos can adhere and scale vertical walls with the help of fibrillar 'hairy structures' that are found on their feet. [11][12][13][14] Each fibril is essentially a hierarchical structure that consists of micron-sized keratinous hairlike structures (satae), which further branches out into hundreds of nanometer sized structures called spatulas.…”

Section: Introductionmentioning

confidence: 99%

Durable adhesives based on electrospun poly(vinylidene fluoride) fibers

Sahay

Baji

Ranganath

et al. 2016

J of Applied Polymer Sci

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Herein, the fabrication of poly(vinylidene fluoride) (PVDF) fibrous membrane using electrospinning is reported and its use for dry‐adhesive applications is demonstrated. The shear and normal adhesion performance of the samples was investigated using an Instron tensile tester and an atomic force microscope (AFM) respectively. For shear adhesion measurements, the electrospun membrane was finger pressed on to a glass slide and pulled in shear mode using a tensile tester. The thickness of the electrospun membrane was varied and the effect of thickness on shear adhesion was investigated. The shear adhesion strength increased when the thickness of the samples was reduced. Shear adhesion strength of a 200 µm thick sample was determined to be approximately 0.165 N/cm. For normal adhesion measurements, a flat tipless cantilever was used to indent the sample and then retract back to measure the pull‐off force. High shear adhesion strength and normal pull‐off force recorded are attributed to the fine size of the fibers that conform to the asperities present on the surfaces of the glass slide and the AFM cantilever. The durability of the adhesive was also verified by repeating the AFM adhesion measurements over 1000 consecutive attachment–detachment cycles. The pull‐off force was seen to be constant over 1000 attachment–detachment cycles. Our results indicate that these electrospun fibrous membranes can potentially be used as reusable dry‐adhesives. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44393.

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“…The first ones can be estimated by two major parameters, the junction-breaking shear stress and the junction size, which can be obtained by analytical elastic continuum adhesive contact analyses, such as the JKR (Johnson-Kendall-Roberts [7], DMT (Derjaguin-Muller-Toporov) [8] and MD (Maugis-Dugdale) [9] theories, or by finite element adhesive contact models [10][11][12]. These analyses [7][8][9][10][11][12] are also able to predict pull-off force, contact force and contact area [13]. In the JKR model, adhesive forces (attractive tensile forces) are considered only within the contact region, while in the DMT model, adhesive forces are considered only outside of the contact region, with the assumption of Hertzian behavior for the deformed profile [11].…”

Section: Introductionmentioning

confidence: 99%

Numerical Modeling of Adhesion and Adhesive Failure During the Unidirectional Contact Between Metallic Surfaces

Bortoleto¹,

Prados²,

Seriacopi³

et al. 2014

ABM Proceedings

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A finite element modeling approach was developed to study adhesion phenomena during the unidirectional contact between a two-dimensional plane-strain square and a flat slab. Surfaces were metallic or ceramic, different pairs of materials were analyzed and their adhesion was considered by means of a FORTRAN subroutine (DLOAD), which was connected with commercial finite element code Abaqus and provided surface attractive forces based on the Lennard-Jones interatomic potential. Adhesive loads were considered both during approximation and separation of the surfaces. During the separation step, material transfer between surfaces, due to adhesion, was modeled by means of damage initiation and propagation at the flat slab. The parameters considered in the simulations were normal load, chemical affinity and system size and the different conditions were analyzed by comparison of the interaction forces during approach and withdrawal. This work also presents detailed descriptions of: (i) the evolution of energy dissipation due to adhesion hysteresis, (ii) the formation-growth-breakage of adhesive junctions and (iii) the evolution of stress distribution during the process. Results have indicated that chemical affinity between the bodies in contact is more relevant for adhesion than the applied load. Besides, smaller asperities are less prone to promote adhesive wear, but they may be subjected to high stress concentration effects.

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Numerical analysis of the adhesive forces in nano-scale structure

Cited by 10 publications

References 10 publications

Numerical modeling of adhesion and adhesive failure during unidirectional contact between metallic surfaces

Numerical modeling of adhesion and adhesive failure during unidirectional contact between metallic surfaces

Durable adhesives based on electrospun poly(vinylidene fluoride) fibers

Numerical Modeling of Adhesion and Adhesive Failure During the Unidirectional Contact Between Metallic Surfaces

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