The propagation of fractures during the drying of a colloidal silica suspension confined in a vertical microtube is investigated. During the drying process, the particle concentration increases until gel formation. In the gelled region, the tensile stresses increase and lead to the formation of two vertical perpendicular cracks propagating in the drying direction, dividing the tube into four eq...

Fretting fatigue induced by combined localized cyclic contact motion and external bulk fatigue loadings may result in premature and dramatic failure of the contacting components. Depending on fretting and fatigue loading conditions, crack nucleation and possibly crack propagation can be activated. This paper proposes a procedure for estimating these two damage thresholds. The crack nucleation b...

Mode-I crack propagation in quasi-brittle material such as rock and concrete is studied by a new numerical method, lattice cellular automata. Cellular automaton method is an efficient method that simulates the process of self-organization of the complex system by constructing some simple local rules. It is of the advantage of localization and parallelization. Lattice model can transform a compl...

Ultrasonic in situ monitoring of metal alloys has been successfully demonstrated for determining the presence and size of fatigue damage within a stracture. Ultrasonic techniques, however, only provide an estimate of the state of the stracture at that time and do not predict the remaining fatigue life. On the other hand, a statistical crack propagation approach, which models the expected remain...

Fretting fatigue induced by combined localized cyclic contact motion and external bulk fatigue loadings may result in premature and dramatic failure of the contacting components. Depending on fretting and fatigue loading conditions, crack nucleation and possibly crack propagation can be activated. This paper proposes a procedure for estimating these two damage thresholds. The crack nucleation b...

We review a series of large-scale molecular dynamics studies of dynamic fracture in brittle materials, aiming to clarify questions such as the limiting speed of cracks, crack tip instabilities and crack dynamics at interfaces. This chapter includes a brief introduction of atomistic modeling techniques and a short review of important continuum mechanics concepts of fracture. We find that hyperel...

Crack propagation in oxide glasses at low crack velocities is controlled by stress corrosion. Proper knowledge of the crack tip chemical environment is thus crucial to understand the slow fracture process of these materials. The formation of a liquid condensate in the confined area of the crack tip is theoretically expected and is classically mentioned to explain specific behavior during the cr...

Crack formation is typically undesirable as it represents mechanical failure that compromises strength and integrity. Recently, there have also been numerous attempts to control crack formation in materials with the aim to prevent or isolate crack propagation. In this work, we utilize fragmentation, at submicron and nanometre scales, to create ordered metal oxide film coatings. We introduce a s...

A planar crack generically segments into an array of "daughter cracks" shaped as tilted facets when loaded with both a tensile stress normal to the crack plane (mode I) and a shear stress parallel to the crack front (mode III). We investigate facet propagation and coarsening using in situ microscopy observations of fracture surfaces at different stages of quasistatic mixed-mode crack propagatio...

We here report on a detailed experimental study whose goal is to investigate spontaneous crack propagation in bonded and intact materials subjected to quasi-static far-field tensile loading. The cracks nucleate from a tiny circular hole and are triggered by an exploding wire. They subsequently propagate under the action of a constant far-field load. Dynamic photoelasticity in conjunction with h...