193 research outputs found
Nonlinear explicit analysis and study of the behaviour of a new ring-type brake energy dissipator by FEM and experimental comparison
A FEM comparative analysis of the thermal efficiency among floors made up of clay, concrete and lightweight concrete hollow blocks
New Bidirectional Heavy Device for Launching Bridges Based on Inverted Caterpillar Mechanism
Background: This patent is based on the combination of caterpillar mechanisms and conveyors. Caterpillar tracks support heavy loads and adapt this support according to the ground conditions. Conveyors displace distributed loads continuously and bidirectionally using the force of friction. This paper describes a revision of previous patents related to this innovative design.
Objective: This paper presents an innovative patent to continuously displace heavy structures safely. The mechanism was patented in 2011 as Spanish Patent ES2367737. The combination of these mechanisms provides the design of this patent to displace heavy structures continuously and bidirectionally, while adapting to the deflection of the structures.
Methods: The most important elements of this patent are detailed in the paper. The most innovative component is the load compensation system, which increases the safety of the displacement of heavy structures. This system controls the load applied on the mechanism, and the displacement can be stopped before the collapse of the heavy structure.
Results: An application of the patent for launching bridges using the Incremental Launching Method is presented. This mechanism is used to displace heavy structures using the force of friction.
Conclusion: The patented mechanism is an original contribution for the displacement of heavy structures continuously and bidirectionally. The patent can be used to launch bridges, improving the efficiency, sustainability, and safety of current systems.The authors would like to acknowledge the help of the Spanish Ministry of Economics and Competitiveness through the Research Project ALCANZA, IPT-380000-2010-012 INNPACTO program.
Furthermore, the authors are grateful to project GRUPIN14-004, co-financed with FEDER funds
Flexible membranes anchored to the ground for slope stabilisation: Numerical modelling of soil slopes using SPH
An alternative modelling for flexible membranes anchored to the ground for soil slope stabilisation is presented using Smoothed-Particle Hydrodynamics to model the unstable ground mass in a soil slope, employing a dynamic solve engine. A regression model of pressure normal to the ground, qsim, and also membrane deflection, fsim, have been developed using Design of Experiment. Finally, a comparison between the pressure obtained from numerical simulation and from a limit equilibrium analysis considering infinite slope has been carried out, showing differences in the results, mainly due to the membrane stiffness.The realization of this research paper has been possible thanks to the funding of the following entities: SODERCAN (Sociedad para el Desarrollo de Cantabria), Consejería de Obras Públicas del Gobierno de Cantabria, Iberotalud S.L., Malla Talud Cantabria S.L. and Contratas Iglesias S.L.
The authors wish also to acknowledge the support provided by the GICONSIME Research Group of the University of Oviedo and the GITECO Research Group of the University of Cantabria. We also thank Swanson Analysis Inc. for the use of the ANSYS Academic program
Waste tire rubber particles modified by gamma radiation and their use as modifiers of concrete
En este trabajo se produjo concreto añadiendo hule de llantas de desecho, posteriormente se irradió con rayos gamma, para finalmente evaluar sus propiedades mecánicas. Los efectos de la radiación en el hule de llanta se evaluaron con diferentes técnicas analíticas.in this work, cement concrete specimens were produced with cement, water, rock crushed and sand; this last was partially substituted by particles of waste tire rubber. Then the compression properties of the specimens were evaluated following the experimental parameters: a) gamma irradiation dose (200, 250 and 300 kGy), b) particle size of tire rubber (0.85 and 2.8 mm), and c) particulate concentration of tire rubber (1, 3 and 5 wt. %). In addition, the mechanical compression results were related with the changes on the physicochemical properties of the irradiated tire particles, which were analyzed by FT-IR, Raman, UV–vis, SEM, XRD, TGA and DSC
Recycled cellulose from Tetra Pak packaging as reinforcement of polyester based composites
Addressing the environmental problems caused by waste generated by Tetra Pak packaging, in this work, polyester based composites with 80% of polyester resin and 20% of silica sand were elaborated; where the silica sand was partially replaced by recycled cellulose from waste Tetra Pak containers at concentrations of 1, 2, 4 and 6% by weight. Both recycled cellulose and composite specimens were subjected to ionizing radiation process by using gamma rays. The results show improvements on the mechanical properties (compressive and flexural strength as well as modulus of elasticity) of the composites when they are irradiated at 100 and 200 kGy. Such improvements can be related with the structural modifications caused by gamma irradiation on the cellulose fibers, including changes in the morphology and the crystallinity; which were analyzed through to SEM, IR and XRD techniques
New launching method for steel bridges based on a self-supporting deck system: FEM and DOE analyses
This paper studies a new launching method for steel bridges based on a self-supporting deck system. This new and patent-protected procedure is able to launch bridges of a span length up to 150 m, in an economical and sustainable way. The use of the last span segments to reinforce the critical sections during launching replaces other conventional temporarymeans applied nowadays. The main objective of this research paper is to numerically analyse the best double deck configuration aswell as to define an approach to stiffener distribution in order to avoid the patch loading phenomenon in the slender webs. With this in mind, the pre-design of a triangular cell along the low flange of each web is presented. A three dimensional finite element model (FEM) is built and the design of experiments technique (DOE) is applied to obtain the best bridge configuration. This newconstructionmethod can be used togetherwith a continuous launching systemin order to increase the velocity of the whole operation and to improve safety during launching. Very good results have been obtained, in terms of deflection, patch loading resistance and vertical load on the pushing device. The comparisonwith other different construction systems and the application to a real case allows us to ensure the viability of the method described.the authors wish to acknowledge the financial support provided by the Spanish Ministry of Science and Innovation with funds from ALCANZA Research Project number IPT-380000-2010-12 and BIA-2012-31609. Both projects have been co-financed with FEDER funds (BIA-2012-31609 and IPT-380000-2010-12), “A Way of Making Europe”
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
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