Search results for "Fracture"
showing 10 items of 873 documents
3-D attenuation image of fluid storage and tectonic interactions across the Pollino fault network
2021
SUMMARYThe Pollino range is a region of slow deformation where earthquakes generally nucleate on low-angle normal faults. Recent studies have mapped fault structures and identified fluid-related dynamics responsible for historical and recent seismicity in the area. Here, we apply the coda-normalization method at multiple frequencies and scales to image the 3-D P-wave attenuation (QP) properties of its slowly deforming fault network. The wide-scale average attenuation properties of the Pollino range are typical for a stable continental block, with a dependence of QP on frequency of $Q_\mathrm{ P}^{-1}=(0.0011\pm 0.0008) f^{(0.36\pm 0.32)}$. Using only waveforms comprised in the area of seism…
Multidomain BEM for crack analysis in stiffened anisotropic plates.
2014
The present paper is concerned with the application of a boundary element model for the analysis of cracks in stiffened composite panels. The panel stiffeners are reduced to equivalent strips and the multidomain technique is used to model panel zones presenting different properties (skin and stiffeners equivalent strip). Also the crack is modeled exploiting the multidomain formulation. Evaluation of stress intensity factors is performed for representative problems.
Estimating Lower Limb Skeletal Loading
2011
Osteoporosis, accidents and subsequent bone fractures cause suffering on an individual level, as well as an economical burden to the society (Ortiz-Luna et al., 2009; Stevens & Olson, 2000). It has been estimated that, in Finland alone, between 30,000 to 40,000 osteoporosis-related fractures occur annually and that 400,000 Finnish people have osteoporosis (Duodecim, 2008). There are a few potential ways of preventing bone fracture, i.e. strengthening bones and/or preventing falls (Ortiz-Luna et al., 2009; Stevens & Olson, 2000). In order to withstand prevalent loading without breaking; while remaining relatively light in weight to allow for locomotion, bones have the ability to adapt their …
Osteosynthesetechniken bei proximalen Humerusfrakturen
2001
Proximale Humerusfrakturen sind haufige Verletzungen. Die Frage der optimalen osteosynthetischen Behandlung instabiler und dislozierter 2- bis 4-Segmentfrakturen ist nach wie vor nicht einhellig geklart. Die operative Therapie befindet sich in der Konfliktsituation zwischen der Forderung einer anatomischen Reposition und stabilen Frakturretention auf der einen Seite und der Notwendigkeit einer maximalen intraoperativen Schonung der periglenohumeralen Weichteilstrukturen und Blutversorgung des Oberarmkopfs, mit dem Ziel das iatrogene Risiko der avascularen Kopfnekrose zu minimieren, andererseits. Wahrend Minimalosteosynthesen, bei denen die Reposition indirekt oder percutan erfolgt, Vorteile…
2020 Reply to: Denosumab for bone health in prostate and breast cancer patients receiving endocrine therapy? A systematic review and a meta-analysis …
2020
Fracture Toughness and Bridging Law of 3D Woven Composites
2003
ABSTRACT In the paper, the methodology of measuring G 1 c by using DCB specimens in the presence of large-scale bridging is adapted for investigating the delamination in 3D woven composites. The main novelties introduced in the DCB testing concern a) the loading device, b) the specimen geometry, c) the measurement scheme, and d) the determination of G 1 c and the bridging law from experimental data. The geometry-independent material characteristic G 1c as a function of the initial crack opening displacement (ICOD) is introduced. Typical values of the delamination fracture toughness of 3D glass and carbon composites are presented.
Fracture mechanics of snow avalanches.
2001
Dense snow avalanches are analyzed by modeling the snow slab as an elastic and brittle plate, attached by static friction to the underlying ground. The grade of heterogeneity in the local fracture (slip) thresholds, and the ratio of the average substrate slip threshold to the average slab fracture threshold, are the decisive parameters for avalanche dynamics. For a strong pack of snow there appears a stable precursor of local slips when the frictional contacts are weakened (equivalent to rising temperature), which eventually trigger a catastrophic crack growth that suddenly releases the entire slab. In the opposite limit of very high slip thresholds, the slab simply melts when the temperatu…
Effect of Water on the Mechanical Behaviour of Extruded Flat Bread
1997
Abstract The effect of water on the mechanical properties of extruded breads was studied, at room temperature. As the moisture content was increased from 6 to 9% moisture, the resistance to fracture (compression tests) or rupture (tensile tests) was improved. Above this moisture range, plasticisation by water was the dominant phenomenon. The brittle to ductile transition was observed to occur within a moisture content range from 9 to 13·7% (w/w). The influence of water on the crispness of extruded bread, evaluated with sensory evaluation, is also described.
Fracture and Fatigue of Travelling Plates
2013
In this chapter, problems of fracture and stability of a moving plate, travelling in a system of rollers at a constant velocity, are studied. It is known that in the manufacturing process, there may occur many kinds of defects in the paper web, such as edge cracks and blister and fiber cuts. Our aim is to tackle this problem and analyse theoretically how the defects change the behaviour. We will use the model of a thin elastic plate made of brittle material. A plate with initial cracks is studied, subjected to constant tension and cyclic tension. As a result, we will show how to find safe parameter ranges of transport velocities and in-plane tensions when fracture, stability and constraints…