laboratoire de physique statistique
 
 
laboratoire de physique statistique

Publications

Rechercher
2007 


Martine BEN AMAR 


3
P U B L I C A T I O N S



 
2007
Periodic lipidic membrane tubes - Campelo, F. and Allain, J. -M. and Ben Amar, M.
EPL 77 (2007) 
LPS


Abstract : We investigate the formation of two-phase lipidic tubes of membrane in the framework of the Canham-Helfrich model. The two phases have different elastic moduli (bending and Gaussian rigidity), different tensions and a line tension prevents the mixing. For a set of parameters close to experimental values, periodic patterns with arbitrary wavelength can be found numerically. A wavelength selection is detected via the existence of an energy minimum. When the chemical composition induces an important enough size disequilibrium between both phases, a segregation into two half infinite tubes is preferred to a periodic structure. Copyright (C) EPLA, 2007.
On the definition and modeling of incremental, cumulative, and continuous growth laws in morphoelasticity - Goriely, Alain and Ben Amar, Martine
BIOMECHANICS AND MODELING IN MECHANOBIOLOGY 6289-296 (2007) 
LPS


Abstract : In the theory of elastic growth, a growth process is modeled by a sequence of growth itself followed by an elastic relaxation ensuring integrity and compatibility of the body. The description of this process is local in time and only corresponds to an incremental step in the total growth process. As time evolves, these incremental growth steps are compounded and a natural question is the description of the overall cumulative growth and whether a continuous description of this process is possible. These ideas are discussed and further studied in the case of incompressible shells.
Roughness of moving elastic lines: Crack and wetting fronts - Katzav, E. and Adda-Bedia, M. and Ben Amar, M. and Boudaoud, A.
PHYSICAL REVIEW E 76 (2007) 
LPS


Abstract : We investigate propagating fronts in disordered media that belong to the universality class of wetting contact lines and planar tensile crack fronts. We derive from first principles their nonlinear equations of motion, using the generalized Griffith criterion for crack fronts and three standard mobility laws for contact lines. Then we study their roughness using the self-consistent expansion. When neglecting the irreversibility of fracture and wetting processes, we find a possible dynamic rough phase with a roughness exponent of zeta=1/2 and a dynamic exponent of z=2. When including the irreversibility, we conclude that the front propagation can become history dependent, and thus we consider the value zeta=1/2 as a lower bound for the roughness exponent. Interestingly, for propagating contact line in wetting, where irreversibility is weaker than in fracture, the experimental results are close to 0.5, while for fracture the reported values of 0.55-0.65 are higher.