The crack growth properties of several sealing glasses were measured by using constant stress rate testing in 2% and 95% RH (relative humidity). Crack growth parameters measured in high humidity are systematically smaller (n and B) than those measured in low humidity, and crack velocities for dry environments are 100 lower than for wet environments. The crack velocity is very sensitivity to sma...

We study the scaling of two-dimensional crack roughness using large scale beam lattice systems. Our results indicate that the crack roughness obtained using beam lattice systems does not exhibit anomalous scaling in sharp contrast to the simulation results obtained using scalar fuse lattices. The local and global roughness exponents (zetaloc and zeta, respectively) are equal to each other, and ...

Stress corrosion cracks (SCC) in low-pressure steam turbine discs are serious hidden dangers to production safety in the power plants, and knowing the orientation and depth of the initial cracks is essential for the evaluation of the crack growth rate, propagation direction and working life of the turbine disc. In this paper, a method based on phased array ultrasonic transducer and artificial n...

For a crack in a structure, the crack driving force G is the reduction of the elastic energy in the structure, associated with the crack extending per unit area. In principle, G can be calculated by solving a boundary value problem. In practice, however, such a calculation is prohibitively difficult for integrated structures of complex architectures, diverse materials and small features. The ca...

Fracture toughness resistance curves describe a material's resistance against crack propagation. These curves are often used to characterize biomaterials like bone, nacre or dentin as these materials commonly exhibit a pronounced increase in fracture toughness with crack extension due to co-acting mechanisms such as crack bridging, crack deflection and microcracking. The knowledge of appropriat...

Understanding sub-Rayleigh-to-intersonic transition of mode II cracks is a fundamental problem in fracture mechanics with important practical implications for earthquake dynamics and seismic radiation. In the Burridge–Andrews mechanism, an intersonic daughter crack nucleates, for sufficiently high prestress, at the shear stress peak traveling with the shear wave speed in front of the main crack...

Additive manufactured components have a different metallurgic structure and are more prone to fatigue cracks than conventionally produced metals. In earlier papers, an effective Structural Health Monitoring solution was presented to detect fatigue cracks in additive manufactured components. Small subsurface capillaries are embedded in the structure and pressurized (vacuum or overpressure). A cr...

An elastic-plastic analysis is performed for two problems relevant to fracture mechanics: a semi­ infinite body with an edge crack in a far out-of-plane shearing field and an infinite plate under plane stress conditions containing a finite line crack in a remote tensile field. Amplitudes of the dominant singularity in the plastic region at the crack tip, the plastic stress and strain intensity ...

In previous studies, enamel showed indications to occlude small cracks in-vivo and exhibited R-curve behaviors for bigger cracks ex-vivo. This study quantifies the crack tip's toughness (K(I0),K(III0)), the crack's closure stress and the cohesive zone size at the crack tip of enamel and investigates the toughening mechanisms near the crack tip down to the length scale of a single enamel crystal...

In the current research work, the problem of fracture mechanics in a plate with a central hole under tensile loading is studied. The stress intensity factors are calculated for a finite plate containing two symmetrical hole-edge cracks. The problem is solved by two different methods, namely the finite element method and the FRANC software analysis. At first the finite element method is used and...