Antonio Papangelo's blog

R. Sahli, G. Pallares, A. Papangelo, M. Ciavarella, C. Ducottet, N. Ponthus, and J. Scheibert
Phys. Rev. Lett. 122, 214301 – https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.214301

Adhesion is a key factor in many tribological processes, especially wear. We generalize a recent formulation for the indentation of a multilayered material using an efficient integral transform method, to the case of adhesion, using a simple energetic transformation in the JKR regime. Then, we specialize the study for the geometry of the Surface Force Apparatus, which consists of two thin layers on a substrate, where the intermediate layer is softer than the other two. We find the pull-off force under "force control" (i.e.

Just published in Journal of the Royal Society Interface

Ciavarella M, Joe J, Papangelo A, Barber JR. 2019 The role of adhesion in contact mechanics. J. R. Soc. Interface 16: 20180738. http://dx.doi.org/10.1098/rsif.2018.0738

Abstract

The anomalous propagation of short cracks shows generally exponential fatigue crack growth but the dependence on stress range at high stress levels is not compatible with Paris’ law with exponent m=2. Indeed, some authors have shown that the standard uncracked SN curve is obtained mostly from short crack propagation, assuming that the crack size a increases with the number of cycles N as da/dN=H\Delta\sigma^h where h is close to the exponent of the Basquin’s power law SN curve.

In recent years there has been a growing interest into high performance bioinspired adhesives. This communication focuses on the adhesive behavior of a rigid cylinder that indents an elastic layer coated on a rigid substrate. With the assumption of short range adhesive interactions (JKR type) the adhesive solution is obtained very easily starting from the adhesiveless one.

The fundamental problem of friction in the presence of macroscopic adhesion, as in soft bodies, is receiving interest from many experimentalists. Since the first fracture mechanics 'purely brittle' model of Savkoor and Briggs, models have been proposed where the mixed mode toughness is interpreted with phenomenological fitting coefficients introducing weaker coupling between modes than expected by the "purely brittle" model.

M.Ciavarella, P.D’Antuono, A.Papangelo

Politecnico di Bari, 70125 Bari, Italy. mciava@poliba.it

Abstract

Congratulations to Prof. M. Ciavarella for having been nominated a new member of the International Journal of Mechanical Sciences (IJMS) Editorial Board! IJMS is a well-established Journal published by Elsevier. With its Impact Factor being 2.884 in 2016, IJMS ranks No. 15 among 133 journals in the field of Mechanics! 

https://www.journals.elsevier.com/international-journal-of-mechanical-sc...

Congratulations!

Antonio

DOI10.22190/FUME180109011C

Prof. Michele Ciavarella, Dr. Antonio Papangelo

Abstract: In the present paper we investigate indentation of a power-law axisymmetric rigid probe in adhesive contact with a "thin layer" laying on a rigid foundation for both frictionless unbounded and bounded compressible cases. The investigation relies on the "thin layer" assumption proposed by Johnson, i.e. the layer thickness being much smaller than the radius of the contact area, and it makes use of the previous solutions proposed by Jaffar and Barber for the adhesiveless case.

• Journal of Sound and Vibration

A. Papangelo (a,*), N. Hoffmann (a,b), A. Grolet (c), M. Stender (a), M. Ciavarella (d)

a) Hamburg University of Technology, Department of Mechanical Engineering, Am Schwarzenberg-Campus 1, 21073, Hamburg, Germany

b) Imperial College London, Exhibition Road, London, SW7 2AZ, UK

 Article in Physical Mesomechanics · December 2017

A. Papangelo · M. Ciavarella · N. Hoffmann

Abstract

Load separation curves between self-affine rough surfaces have been studied by means of extensive numerical simulations. The results of the comparison with the two main contact mechanics theories have been reported. https://www.nature.com/articles/s41598-017-07234-4