We report a novel mode of quasi-static oscillatory crack propagation when a cutting tool is driven through a thin polymer film [6,7]. In our experiments, for tools with a large enough width, the crack tip follows a highly periodic path, leaving behind a striking oscillatory pattern. Taking into account the separation of the film's bending and stretching energies and using classical fracture the...

– The dynamics of planar crack fronts in heterogeneous media is studied using a recently proposed stochastic equation of motion that takes into account nonlinear effects. The analysis is carried for a moving front in the quasi-static regime using the Self Consistent Expansion. A continuous dynamical phase transition between a flat phase and a dynamically rough phase, with a roughness exponent ζ...

Earlier [ 1] we described an experimental procedure aimed at exarnining the spatial and temporal distribution of energy dissipation during crack initiation and propagation in a ductile polymer. The experiment combines a table-top tensile tester and an infrared imaging system. Because of the intense heating of the crack tip region, direct observation of the temperature rise not only provides an ...

RICE et ml. (1994, J. Mech. Ph_vs. Solids 42, 813-843) analyse the propagation of a planar crack with a nominally straight front in a model elastic solid with a single displacement component. Using the form of their results for a strictly linearized perturbation from a straight crack front which moves at uniform speed, we give the corresponding first-order expression for the deviation of a crac...

We investigated the microstructural and fatigue characteristics on consolidated Japanese cedar called “ObiSugi (Cryptomeria japonicain)” fabricated by hot-pressing. Hot-press treatment was conducted at various conditions. Three point bending test, hardness test and plane bending fatigue test of consolidated wood were carried out to investigate mechanical properties. Flexural strength of consoli...

We study experimentally the propagation of an in-plane fracture into a transparent and heterogeneous Plexiglas block. A stable crack propagation in mode I is monitored by an imposed displacement. The experimental setup allows a high resolution observation of the crack front in situ. Self-affine properties of the crack front are described over more than three decades using several techniques: va...

The authors have been developing a crack propagation analysis system that can deal with arbitrary shaped cracks in threedimensional solids. The system is consisting of mesh generation software, a large-scale finite element analysis program and a fracture mechanics module. To evaluate the stress intensity factors, a Virtual Crack Closure-Integral Method (VCCM) for the second-order tetrahedral fi...

X-Ray Diffraction Contrast Tomography (DCT) is a recently developed, non-destructive synchrotron imaging technique which characterizes microstructure and grain orientation in polycrystalline materials in three dimensions (3D). By combining it with propagation based Phase Contrast Tomography (PCT) it is possible to get a full picture description for the analysis of local crack growth rate of sho...

Total-energy pseudopotential calculations are used to study the cleavage anisotropy in silicon. It is shown that cracks propagate easily on 111 and 110 planes provided crack propagation proceeds in the <1;10> direction. In contrast, if the crack is driven in a <001> direction on a 110 plane the bond breaking process is discontinuous and associated with pronounced relaxations of the surrounding ...