Strength of adhesive contact between a rough fibrillar structure and an elastic body: influence of fibrillar stiffness

2021 ◽  
pp. 1-14
Author(s):  
Xin He ◽  
Qiang Li ◽  
Valentin L. Popov
Keyword(s):  
Elastic Body ◽  
Adhesive Contact ◽  
Fibrillar Structure

scholarly journals Strength statistics of adhesive contact between a fibrillar structure and a rough substrate

2007 ◽  
Vol 5 (21) ◽  
pp. 441-448 ◽  
Author(s):  
Pankaj K Porwal ◽  
Chung Yuen Hui
Keyword(s):  
Adhesion Strength ◽  
Probability Distributions ◽  
Adhesive Contact ◽  
Strength Distribution ◽  
Fibrillar Structure ◽  
Substrate Roughness ◽  
Equal Distribution ◽  
Fibril Structure ◽  
Attachment Strength ◽  
Fibril Length

Equal distribution of load among fibrils in contact with a substrate is an important characteristic of fibrillar structures used by many small animals and insects for contact and adhesion. This is in contrast with continuum systems where stress concentration dominates interfacial failure. In this work, we study how adhesion strength of a fibrillar system depends on substrate roughness and variability of the fibril structure, which are modelled using probability distributions for fibril length and fibril attachment strength. Monte Carlo simulations are carried out to determine the adhesion strength statistics where fibril length follows normal or uniform distribution and attachment strength has a power-law form. Our results indicate that the strength distribution is Gaussian (normal) for both the uniform and the normal distributions for length. However, the fibrillar structure having normally distributed lengths has higher strength and lower toughness than one having uniformly distributed lengths. Our simulations also show that an increase in the compliance of the fibrils can compensate for both the substrate roughness and the attachment strength variation. We also show that, as the number of fibrils n increases, the load-carrying efficiency of each fibril goes down. For large n , this effect is found to be small. Furthermore, this effect is compensated by the fact that the standard deviation of the adhesive strength decreases as .

Functional amyloid: widespread in Nature, diverse in purpose

2014 ◽  
Vol 56 ◽  
pp. 207-219 ◽  
Author(s):  
Chi L.L. Pham ◽  
Ann H. Kwan ◽  
Margaret Sunde
Keyword(s):  
Spider Silk ◽  
Epigenetic Inheritance ◽  
Fibrillar Structure ◽  
Cytoplasmic Polyadenylation ◽  
Functional Amyloid ◽  
Interacting Protein ◽  
Diverse Range ◽  
Element Binding Protein ◽  
Functional Amyloids ◽  
Micro Organisms

Amyloids are insoluble fibrillar protein deposits with an underlying cross-β structure initially discovered in the context of human diseases. However, it is now clear that the same fibrillar structure is used by many organisms, from bacteria to humans, in order to achieve a diverse range of biological functions. These functions include structure and protection (e.g. curli and chorion proteins, and insect and spider silk proteins), aiding interface transitions and cell–cell recognition (e.g. chaplins, rodlins and hydrophobins), protein control and storage (e.g. Microcin E492, modulins and PMEL), and epigenetic inheritance and memory [e.g. Sup35, Ure2p, HET-s and CPEB (cytoplasmic polyadenylation element-binding protein)]. As more examples of functional amyloid come to light, the list of roles associated with functional amyloids has continued to expand. More recently, amyloids have also been implicated in signal transduction [e.g. RIP1/RIP3 (receptor-interacting protein)] and perhaps in host defence [e.g. aDrs (anionic dermaseptin) peptide]. The present chapter discusses in detail functional amyloids that are used in Nature by micro-organisms, non-mammalian animals and mammals, including the biological roles that they play, their molecular composition and how they assemble, as well as the coping strategies that organisms have evolved to avoid the potential toxicity of functional amyloid.

Studies Regarding the Architectural Design of Various Composites and Nanofibres Used in Dental Medicine

2018 ◽  
Vol 69 (2) ◽  
pp. 328-331
Author(s):  
Irina Gradinaru ◽  
Leonard Ignat ◽  
Cristina Gena Dascalu ◽  
Laurentiu Valentin Soroaga ◽  
Magda Ecaterina Antohe
Keyword(s):  
Composite Structures ◽  
Architectural Design ◽  
Dental Restoration ◽  
Fibrillar Structure ◽  
Fiber Post ◽  
Fiber Glass ◽  
Full Agreement ◽  
Sem Images ◽  
Structural Modifications ◽  
New Formulation

The aim of this study was represented by the definition and testing of a new formulation strategy and the functionality of composite materials, while ensuring the optimization of the relevant properties for the dental restoration processes through the use of precise techniques of characterization, the modification and functionality of the components in view of obtaining results that are characterized by an optimum biomechanical and bioactive relation, in full agreement with the particularities of the dental structure that requires restoration. In view of obtaining new resistant composite structures we made a number of 10 samples including extracted teeth with various losses of dental substance and the structural modifications included 3 types of composites, whose structure was improved by the introduction of inorganic fillings based on hydroxyapatite and silver nanoparticles. All these structures were reinforced with two types of fibers, Reforpost fiber glass kit (Angelus) and Fiber post Schulzer Pre-silanized; With regard to the use of composite structures improved by HA addition, we notice a slight lacunary structure on the SEM images due to the properties of HA, an aspect present at much smaller dimensions in the silver � HA mix. The size of the grains associated with their continuous uniformity and adherence for the fibrillar structure stands out at the samples with hydroxyapatite, the first place as uniformity and adherence going to the composite of the nanofiller technology category.

Modifications of the Godunov method for computing disturbance propagation in an elastic body

2016 ◽  
Vol 11 (1) ◽  
pp. 119-126 ◽  
Author(s):  
A.A. Aganin ◽  
N.A. Khismatullina
Keyword(s):  
Elastic Body ◽  
Godunov Method ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Order Accuracy ◽  
One Dimensional ◽  
Disturbance Propagation ◽  
Linear Waves ◽  
Longitudinal And Shear Waves ◽  
Contact Discontinuities

Numerical investigation of efficiency of UNO- and TVD-modifications of the Godunov method of the second order accuracy for computation of linear waves in an elastic body in comparison with the classical Godunov method is carried out. To this end, one-dimensional cylindrical Riemann problems are considered. It is shown that the both modifications are considerably more accurate in describing radially converging as well as diverging longitudinal and shear waves and contact discontinuities both in one- and two-dimensional problem statements. At that the UNO-modification is more preferable than the TVD-modification because exact implementation of the TVD property in the TVD-modification is reached at the expense of “cutting” solution extrema.

Mechanical modeling and characteristic study for the adhesive contact of elastic layered media

2017 ◽  
Vol 50 (47) ◽  
pp. 475601 ◽  
Author(s):  
Yuyan Zhang ◽  
Xiaoli Wang ◽  
Qiaoan Tu ◽  
Jianjun Sun ◽  
Chenbo Ma
Keyword(s):  
Layered Media ◽  
Adhesive Contact ◽  
Mechanical Modeling

Identification of a plane crack in an elastic body by invariant integrals

2008 ◽  
Vol 43 (3) ◽  
pp. 437-452 ◽  
Author(s):  
A. V. Kaptsov ◽  
E. I. Shifrin
Keyword(s):  
Elastic Body ◽  
Plane Crack ◽  
Invariant Integrals
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