355 citations · 2.6k across the 109 of their papers we have counts for
16 papers · 1 filter
Fatigue and failure of a polymer chain under tension
Harish Charan, Alex Hansen, H. G. E. Hentschel +1
The rupture of a polymer chain maintained at temperature under fixed tension is prototypical to a wide array of systems failing under constant external strain and random pertur…
Implications of Realistic Fracture Criteria on Crack Morphology
Bjørn Skjetne, Alex Hansen
We study the effects realistic fracture criteria have on crack morphology obtained in numerical simulations with a stochastic discrete element method. Results are obtained with two…
A Renormalization Group Procedure for Fiber Bundle Models
Srutarshi Pradhan, Alex Hansen, Purusattam Ray
We introduce two versions of a renormalization group scheme for the equal load sharing fiber bundle model. The renormalization group is based on formulating the fiber bundle model…
Model for Density Waves in Gravity-Driven Granular Flow in Narrow Pipes
Simen Å. Ellingsen, Knut S. Gjerden, Morten Grøva +1
A gravity-driven flow of grains through a narrow pipe in vacuum is studied by means of a one-dimensional model with two coefficients of restitution. Numerical simulations show clea…
Ridge Network in Crumpled Paper
Christian Andre Andresen, Alex Hansen, Jean Schmittbuhl
The network formed by ridges in a straightened sheet of crumpled paper is studied using a laser profilometer. Square sheets of paper were crumpled into balls, unfolded and their he…
Rupture processes in fiber bundle models
Per C. Hemmer, Alex Hansen, Srutarshi Pradhan
Fiber bundles with statistically distributed thresholds for breakdown of individual fibers are interesting models of the static and dynamics of failures in materials under stress.…
Crossover behavior in failure avalanches
Srutarshi Pradhan, Alex Hansen, Per C. Hemmer
Composite materials, with statistically distributed threshold for breakdown of individual elements, are considered. During the failure process of such materials under external stre…
Scaling Laws of Stress and Strain in Brittle Fracture
Bjorn Skjetne, Torbjorn Helle, Alex Hansen
A numerical realization of an elastic beam lattice is used to obtain scaling exponents relevant to the extent of damage within the controlled, catastrophic and total regimes of mod…
Effects of Buckling on Stress and Strain in Thin Randomly Disordered Tension-Loaded Sheets
Bjorn Skjetne, Torbjorn Helle, Alex Hansen
We study how crack buckling affects stress and strain in a thin sheet with random disorder. The sheet is modeled as an elastic lattice of beams where each of the beams have individ…
Stochastic Model for the Interaction of Buckling and Fracture in Thin Tension-Loaded Sheets
Bjorn Skjetne, Torbjorn Helle, Alex Hansen
We introduce a model of fracture which includes the out-of-plane degrees of freedom necessary to describe buckling in a thin-sheet material. The model is a regular square lattice o…
Brittle Crack Roughness in Three-Dimensional Beam Lattices
Bjorn Skjetne, Torbjorn Helle, Alex Hansen
The roughness exponent is reported in numerical simulations with a three-dimensional elastic beam lattice. Two different types of disorder have been used to generate the breaking t…
A new relation between pressure and fractional flow in two-phase flow in porous media
Henning Arendt Knudsen, Alex Hansen
We study average flow properties in porous media using a two-dimensional network simulator. It models the dynamics of two-phase immiscible bulk flow where film flow can be neglecte…
Burst dynamics during drainage displacements in porous media: Simulations and experiments
Eyvind Aker, Knut Jorgen Maloy, Alex Hansen +1
We investigate the burst dynamics during drainage going from low to high injection rate at various fluid viscosities. The bursts are identified as pressure drops in the pressure si…
Critical aspects of hierarchical protein folding
Alex Hansen, Mogens H. Jensen, Kim Sneppen +1
We argue that the first order folding transitions of proteins observed at physiological chemical conditions end in a critical point for a given temperature and chemical potential o…
Fracture in Three-Dimensional Fuse Networks
G. George Batrouni, Alex Hansen
We report on large scale numerical simulations of fracture surfaces using random fuse networks for two very different disorders. There are some properties and exponents that are di…
Band Formation during Gaseous Diffusion in Aerogels
M. A. Einarsrud, F. A. Maao, A. Hansen +2
We study experimentally how gaseous HCl and NH_3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The rea…