Filters








1,010 Hits in 2.1 sec

The Theory of Multiple Peeling [article]

Nicola M. Pugno
2009 arXiv   pre-print
In this paper we solve the multiple peeling problem by applying a fracture mechanics approach to a complex system of films, adhering to the substrate and having a common hinge, where the pulling force is applied. The simplest V-shaped system, consisting of two identical peeling tapes is considered as a case study (to be solved coupling six nonlinear equations); an optimal peeling angle, at which adhesion is maximal, is discovered.
arXiv:0903.0935v1 fatcat:mpkuzbvrq5df5gfofdppnvpj6i

Optimal Angles for Maximal Adhesion in Living Tokay Geckos

Emiliano Lepore, Francesco Pugno, Nicola M. Pugno
2012 The journal of adhesion  
M., K. Autumn, and J.  ...  per gecko), t F ¼ 10 mm) and toes (n T ¼ 5 (five toes per each foot), t T ¼ 4 mm), the Young modulus E T ¼ E F ¼ 1 GPa, and, using the work of adhesion, c, of [53] (varying in the range 10 3 -10 6 J=m  ... 
doi:10.1080/00218464.2012.705639 fatcat:nd7mwnr4mzbknfn4wivjzirjpa

Quantized fracture mechanics

Nicola M. Pugno †, Rodney S. Ruoff ‡
2004 Philosophical Magazine  
M. Pugno and R. S.  ...  M. Pugno and R. S. Ruoff } 9.  ...  A simple estimation of the fracture toughness could be obtained considering the bond dissociation energy from the Brenner potential (124 kcal/mole of C-C bonds), yielding % 4.46 N/m.  ... 
doi:10.1080/14786430412331280382 fatcat:rfyhnkpvhjcuhnncunwau6veeu

A Universal Scaling Law for Nanoindentation, But Not only [article]

Nicola M. Pugno
2006 arXiv   pre-print
GPa 1 . 0 ≈ macro H µm 200 * ≈ R GPa 2 ≈ nano H GPa 9 . 0 ≈ macro H µm 6 . 3 * ≈ R GPa 2 ≈ nano H Furthermore, we note that at the truly nanoscale we expect even higher values for .  ...  Similar results with the same sets of parameters were observed for pyramidal µm 80 < R GPa 9 . 0 ≈ macro H , or (b) µm 250 * ≈ R GPa 6 . 0 ≈ macro H , .  ... 
arXiv:cond-mat/0601369v1 fatcat:tssoit2kajdl3bojzv5ihaan24

Flexible nanovectors

Nicola M Pugno
2008 Journal of Physics: Condensed Matter  
A = M 2m/3 m F A (20) where M m is the number of sub-nanovectors at the stage m.  ...  Note that, from equation (9) , the ratio between the total adhesion forces required to delaminate the M sub-nanovectors and the mother nanovector is F (M) A = M 2/3 F A , and for m stages: F (M m ,m)  ... 
doi:10.1088/0953-8984/20/47/474205 fatcat:td5xc4fd6bbbpkidmbmwomuuxm

Space elevator: out of order?

Nicola M. Pugno
2007 Nano Today  
The probability of finding a nanocrack of size m in a bundle with vacancy fraction f is P(m) = (1 -f)f m . Thus the number M of such nanocracks in a bundle composed of N atoms is M(m) = P(m)N.  ...  (in fracture quanta units), σ N (m)/σ N (theo) ≈ (1 + m) -½ (b ≈ 0, m ≈ 2a/q).  ... 
doi:10.1016/s1748-0132(07)70173-1 fatcat:26wnm3zy4fbobeoo4aat2wtzby

Graded cross-links for stronger nanomaterials

Nicola M. Pugno
2010 Materials Today  
For example, considering a chain composed of M perfectly rigid cross-links and subsequently N−M perfectly compliant ones, would occur at a force F = f for the first M cross-links; in order to reach the  ...  global failure we must increase the force up to a value of F c = (N -M)f.  ... 
doi:10.1016/s1369-7021(10)70032-8 fatcat:y3vpxmmebvggjda57g3np3mqxi

Micro- or nano-mechanics

Alberto Corigliano, Nicola M. Pugno
2013 Meccanica (Milano. Print)  
doi:10.1007/s11012-013-9792-x fatcat:zlkf665lhraerlo2md3pcei2dy

Thermomechanical Stresses in Fullerenes at Nanotube

Nicola M. Pugno
2008 Journal of Nanomaterials  
This suggests that fullerenes (other types of nanoparticles can Nicola M.  ...  Pugno 5 be envisioned too) could be released from the nanotube by thermal activation, a perhaps useful concept for producing innovative two-stage nanovectors capable of smartly delivering the fullerenes  ... 
doi:10.1155/2008/156724 fatcat:u57h3vzb7bdkxjotb6odwq33nm

Young's modulus reduction of defective nanotubes

Nicola M. Pugno
2007 Applied Physics Letters  
Pugno Appl. Phys. Lett. 90, 043106 ͑2007͒ 1 TABLE II .  ...  M.  ... 
doi:10.1063/1.2425048 fatcat:gen4xr2ltfhg3iqojbvgc6346a

Introduction

Cengiz S. Ozkan, Markus J. Buehler, Nicola M. Pugno, Kang Wang
2013 Journal of Materials Research  
doi:10.1557/jmr.2013.14 fatcat:wmdp2j6mzzffpciixqgf6z66ni

The theory of multiple peeling

Nicola M. Pugno
2011 International Journal of Fracture  
development of spiderman suit like tissues (Pugno 2007b (Pugno , 2008 .  ...  2007a; Pugno and Lepore 2008a,b; Bhushan and Sayer 2007) , aiming to explain and possibly mimic their extraordinary adhesive abilities (Geim et al. 2003 ) even at the human size-scale thus towards the  ... 
doi:10.1007/s10704-011-9638-2 fatcat:x23wnraphrhrjd6pbnl2me23w4

Tunable Water Channels with Carbon Nanoscrolls

Xinghua Shi, Yuan Cheng, Nicola M. Pugno, Huajian Gao
2010 Small  
Figure 1B shows how the applied electric field influences the dipole-induced surface energy g dipole normalized by g vdW , typically about 0.2 N m À1 .  ...  Φ/( 2πL) (nN) r 0 +R (nm) γ dipole =-0.042 N/m B=5000 nm 500 nm 50 nm B) |γ dipole |/γ vdW E (V/nm) U r ij ; l À Á ¼ 4le CC s CC r ij 12 À s CC r ij 6 " # (5) Results During the simulations, the CNS-water  ... 
doi:10.1002/smll.200902286 pmid:20196087 fatcat:lahppz7dfngwfgxpmbfj7p5mpy

Fermentation based carbon nanotube bionic functional composites [article]

Luca Valentini, Silvia Bittolo Bon, Stefano Signetti, Manoj Tripathi, Erica Iacob, Nicola M. Pugno
2016 arXiv   pre-print
E m = 1 . 1 46 MPa, while for the daughter cell d d = 4.467 μm and Young's modulus E d = 1.10 MPa.  ...  The G' f-cntpo value obtained is thus ~0.024 N/m.  ... 
arXiv:1603.05407v1 fatcat:r3t2gozgmbfvhdjpeeiud7r6xi

Competition between delamination and fracture in multiple peeling problems [article]

Lucas Brely, Federico Bosia, Ali Dhinojwala, Nicola M. Pugno
2019 arXiv   pre-print
Adhesive attachment systems consisting of multiple tapes or strands are commonly found in nature, for example in spider web anchorages or in mussel byssal threads, and their structure has been found to be ingeniously architected in order to optimize mechanical properties, in particular to maximize dissipated energy before full detachment. These properties emerge from the complex interplay between mechanical and geometric parameters, including tape stiffness, adhesive energy, attached and
more » ... d lengths and peeling angles, which determine the occurrence of three main mechanisms: elastic deformation, interface delamination and tape fracture. In this paper, we introduce a formalism to evaluate the mechanical performance of multiple tape attachments in different parameter ranges, allowing to predict the corresponding detachment behaviour. We also introduce a numerical model to simulate the complex multiple peeling behaviour of complex structures, illustrating its predictions in the case of the staple-pin architecture. We expect the presented formalism and numerical model to provide important tools for the design of bioinspired adhesive systems with tunable or optimized detachment properties.
arXiv:1906.10756v1 fatcat:ve6go3zfmfbtld2av3akojhz6q
« Previous Showing results 1 — 15 out of 1,010 results