This paper presents a novel real-time crack identification method to determine the position and depth of a transverse open crack on a rotating shaft. A newly developed wireless sensor capable of being mounted directly on the shaft is employed to monitor acceleration at different points of the shaft in a rotating coordinate system. The vibration parameters obtained from the wireless sensors and ...

Whether and how fracture mechanics needs to be modified for small length scales and in systems of reduced dimensionality remains an open debate. Here, employing in situ transmission electron microscopy, atomic structures and dislocation dynamics in the crack tip zone of a propagating crack in two-dimensional (2D) monolayer MoS2 membrane are observed, and atom-to-atom displacement mapping is obt...

This paper presents a novel real-time crack identification method to determine the position and depth of a transverse open crack on a rotating shaft. A newly developed wireless sensor capable of being mounted directly on the shaft can be employed to monitor acceleration at different points of a shaft in a rotating coordinate system. The vibration parameters obtained from a Finite Element Model ...

The use of microwave technique has proved to be a viable means for crack detection and sizing surface cracks in metals. In this technique, the surface of the specimen is interrogated with a radiating open-ended waveguide probe and a crack is assumed to be a simple short-circuited rectangular waveguide, causing peturbations in the probe reflection coefficient. Since the growth of fatigue in meta...

In this paper we apply the method developed by Rice [1], of solving for the elastic field of a crack with a front perturbed from some reference shape, to solve the elasticity problems of somewhat circular planar tensile cracks under arbitrary load distributions. The method is based on a known solution for the stress intensity factor along a circular crack due to a pair of wedge-opening point fo...

The fatigue behaviour of single lap bonded joints under fatigue loading was already investigated and a suitable life prediction model was presented and validated [1-2]. The model is based on the actual damage evolution under fatigue load: a crack initiation followed by its propagation up to a critical length [2, 3]. In the present paper the evolution of fatigue damage in single lap joints is ex...

Perturbation of a steadily propagating crack with a straight edge is solved using the method of matched asymptotic expansion (MAE). This provides a simplified analysis in which the inner and outer solutions are governed by distinct mechanics. The inner solution contains the explicit perturbation and is governed by a quasistatic equation. The outer solution determines the radiation of energy awa...

This paper presents a formulation for brittle fracture in 3D elastic solids within the context of configurational mechanics. The local form of the first law of thermodynamics provides a condition for equilibrium of the crack front. The direction of the crack propagation is shown to be given by the direction of the configurational forces on the crack front that maximise the local dissipation. Th...

An efastic half-plane containing a su~ace-b~ak~og crack normal to the free surface, subjected to loading by uniform tractions over a given length af its surface, is considered. The tractions consist of pressure, constant in time, and a shear load, varying sinu~idaily in time, both applied adjacent to the crack. This geometry approximates the classical fretting problem with a resulting fatigue c...

The Open Pluggable Edge Services (OPES) framework is application agnostic. Application specific adaptations extend that framework. Previous work has focused on HTTP and work for SMTP is in progress. These protocols differ fundamentally in the way data flows and it turns out that existing OPES requirements and IAB considerations for OPES need to be reviewed with regards to how well they fit for ...