Publications

This paper examines the interaction of adjacent surface breaking and embedded circumferential flaws in terms of crack driving force. A novel finite element modelling methodology for adjacent planar flaws is adopted, based on element deletion in a densely meshed grid. Element deletion provides a unique capability for modelling multiple surface breaking or embedded flaws, since the mesh design is independent of the geometry of the flaw(s). A newly ...

The acceptance of volumetric weld imperfections is subjected to workmanship guidelines, which are subjective quality criteria loosely related to fitness for purpose assessments. However, the relative impact of such imperfections may be accentuated in fracture toughness tests, given the relatively small dimensions of the test specimens. This study analyses the impact of weld volumetric imperfections on the outcome of fracture toughness tests. ...

The acceptance of weld volumetric imperfections such as porosity from the perspective of structural integrity is guided by workmanship criteria. However, there is a lack of knowledge on how and to what extent volumetric imperfections can affect the outcome of fracture toughness tests. The small size of laboratory test specimens potentializes the relative impact of such imperfections. This study numerically investigates the influence of porosity ...

The actual shape of a real defect differs from the simplified shapes that are assumed within an engineering critical assessment. Additionally, the re-characterization of interacting defects into one simplified defect is known to introduce conservatism, which may be undesirably large. Ongoing and expected technological advances of 3D NDE techniques (such as full-matrix capture ultrasonics and X-ray CT) allow to assume that defect simplification ...

Recent research has shown that fretting fatigue is the main cause of fatigue failure in electrical transmission lines, and this phenomenon can be modeled as a stress concentration problem. The present study investigates the expected fatigue life of aluminum alloy 6201-T81 wires with micro holes, used in cables for transmission lines. The expected fatigue life of wires with micro holes is calculated based on the Theory of Critical Distances ...

The aim of this work is to predict fatigue life of aluminum alloy wires 6201-T81 containing geometric discontinuities using the Theory of Critical Distances (TCD). These wires were taken from a 900 MCM All Aluminum Alloy Conductor (AAAC 900 MCM) used in overhead power transmission lines. The equivalent stress was evaluated by means of the Point Method (PM) and the Volume Method (VM), based on the maximum principal stress (sigma(1)). Regarding ...