999 resultados para Ingeniero de caminos, canales y puertos
Resumo:
Con el presente proyecto tratamos de justificar y definir técnicamente las instalaciones necesarias para el correcto funcionamiento de una nueva bodega para la elaboración de vino de Denominación de Origen Rueda. Para ello, estudiaremos las diferentes alternativas posibles para la construcción de una bodega, así como la comparación entre si de las diferentes alternativas para elegir la mejor de ellas mediante un análisis multicriterio, teniendo en cuenta los distintos factores (económicos, medioambientales, funcionales…) que influyen en la elección de la solución.
Resumo:
The bridge over the Mittellandkanal is located in the municipality of Braunschweig, a city of Low Saxony located in Mid-North Germany, between Berlin and Hannover, 50 km away from this last city. The city of Braunschwig has 248.867 inhabitants (December 2010). The orography of the zone is practically even, with some slopes in the surrounding area, with a no important variation of the ground elevation, characterized by a big uniformity and a great visual quality. In this zone the canal flows from west to east, from the Dortmundkanal until the Elbe river, so it has a length of 325,3 km. The normal flora from the zone is farmland with some little forests not very big and not very important. But the Mittellandkanal lies at the North of Brauschweig, that means that in the zone of the canal there is a change between the urban area and the rural area. For this reason in the zone of the bridge we start to find farmlands and forest, however the constructions and buildings are still present in this area. The railway line that is going to be built will unite the North-center of Germany with the North-East of Germany because some of the following factors: •Overstress of the only existing line in the moment that connects Berlin with the North-East extreme of Germany. •No direct connection with the North-Easth Germany with other important German cities from South and West of Germany. •Replacement of the old existing one way line in the area that has to be renewed. •Modernization of the old railway lines of Germany. Schedule order by the European Union and the German Government. The actual lines of the zone do not have the necessary conditions and characteristics to satisfy the demand of the travelers that want to travel all over Germany with the railway avoiding using other transports like plan or car. For these reasons the necessity of the replacement of the old railway line and the aim to create a union with the North-East Germany that has a deficit of transport infrastructures and connections with the rest of the country and Europe. Although the new railway line provokes some disadvantages when constructing it is indispensable to build this railway line. The pass of the railway line through Braunschweig has not been random. The zone Braunschweig-Wolfsburg is a very industrialized area because of some companies like Wolkswagen and too because this zone is an important pass of important line from Berlin, South and East Germany. For all of these reasons the railway line goes through Braunschweig and connects to the city of Wolfsburg first, and after the North-East Germany zone.
Resumo:
Major ampullate (MA) dragline silk supports spider orb webs, combining strength and extensibility in the toughest biomaterial. MA silk evolved ~376 MYA and identifying how evolutionary changes in proteins influenced silk mechanics is crucial for biomimetics, but is hindered by high spinning plasticity. We use supercontraction to remove that variation and characterize MA silk across the spider phylogeny. We show that mechanical performance is conserved within, but divergent among, major lineages, evolving in correlation with discrete changes in proteins. Early MA silk tensile strength improved rapidly with the origin of GGX amino acid motifs and increased repetitiveness. Tensile strength then maximized in basal entelegyne spiders, ~230 MYA. Toughness subsequently improved through increased extensibility within orb spiders, coupled with the origin of a novel protein (MaSp2). Key changes in MA silk proteins therefore correlate with the sequential evolution high performance orb spider silk and could aid design of biomimetic fibers.
Resumo:
The mechanical behavior and microstructure of minor ampullate gland silk (miS) of two orb-web spinning species, Argiope trifasciata and Nephila inaurata, were extensively characterized, enabling detailed comparison with other silks. The similarities and differences exhibited by miS when compared with the intensively studied major ampullate gland silk (MAS) and silkworm (Bombyx mori) silk offer a genuine opportunity for testing some of the hypotheses proposed to correlate microstructure and tensile properties in silk. In this work, we show that miSs of different species show similar properties, even when fibers spun by spiders that diverged over 100 million years are compared. The tensile properties of miS are comparable to those of MAS when tested in air, significantly in terms of work to fracture, but differ considerably when tested in water. In particular, miS does not show a supercontraction effect and an associated ground state. In this regard, the behavior of miS in water is similar to that of B. mori silk, and it is shown that the initial elastic modulus of both fibers can be explained using a common model. Intriguingly, the microstructural parameters measured in miS are comparable to those of MAS and considerably different from those found in B. mori. This fact suggests that some critical microstructural information is still missing in our description of silks, and our results suggest that the hydrophilicity of the lateral groups or the large scale organization of the sequences might be routes worth exploring.
Resumo:
Damage tolerance of high strength cold-drawn ferritic–austenitic stainless steel wires is assessed by means of tensile fracture tests of cracked wires. The fatigue crack is transversally propagated from the wire surface. The damage tolerance curve of the wires results from the empirical failure load when given as a function of crack depth. As a consequence of cold drawing, the wire microstructure is orientated along its longitudinal axis and anisotropic fracture behaviour is found at macrostructural level at the tensile failure of the cracked specimens. An in situ optical technique known as video image correlation VIC-2D is used to get an insight into this failure mechanism by tensile testing transversally fatigue cracked plane specimens extracted from the cold-drawn wires. Finally, the experimentally obtained damage tolerance curve of the cold-drawn ferritic–austenitic stainless steel wires is compared with that of an elementary plastic collapse model and existing data of two types of high strength eutectoid steel currently used as prestressing steel for concrete.
Resumo:
Three broken steel bars from a sewed crack in a dam are reported. The inspection of the fracture surfaces of the prestressed bars suggests that fractures were triggered by small cracks and by the inherent brittleness of the bars, as fracture toughness was about 40 MPa m1/2. The analysis of the failures shows that the usual design requirements for prestressing bars fail to warn against brittle failures if some damage exists. Some recommendations, based on the concept of damage tolerance, are suggested to avoid similar unfortunate incidents.
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The paper addresses the fracture propagation and stress corrosion behaviour of laser hybrid welds achieved between low carbon steel and stainless steel thin sheets. The crack propagation within these overmatched in strength welds was investigated by crack tip opening displacement (CTOD) on CT specimens notched transverse to the weld. A Digital Image Correlation System was used to qualify and estimate the initial crack length obtained by fatigue. The results are associated with the fractographic examinations of various regions of laser hybrid joints. Stress corrosion behaviour of the joint is also discussed.
Resumo:
En este trabajo se determina la tolerancia al daño de un acero inoxidable austeno-ferrítico trefilado hasta obtener resistencia propias del acero de pretensado. Para ello se han realizado ensayos de fractura sobre alambres con secciones transversales debilitadas por fisuras de fatiga propagadas desde la superficie exterior. La medida de la tolerancia al daño adoptada es la curva empírica carga de rotura-profundidad de fisura. Para valorar cuantitativamente los resultados, se utilizan las curvas de dos aceros de pretensar eutectoides, respectivamente fabricados por trefilado y por tratamiento térmico de templado y revenido, así como un modelo elemental de colapso plástico por tracción para alambres fisurados. La microestructura austeno-ferrítico de los alambres inoxidables adquiere una marcada orientación en la dirección de trefilado, que induce una fuerte anisotropía de fractura en los alambres y condiciona su mecanismo macroscópico de colapso a tracción cuando están Asurados. Para observar este mecanismo se ha utilizado la técnica VIC-2D de adquisición y análisis computerizado de imágenes digitales en ensayos mecánicos, aplicándola a ensayos de fractura a tracción realizados con probetas planas de alambre inoxidable trefilado Asuradas transversalmente. Damage tolerance of a high strength cold-drawn ferritic-austenitic stainless steel is assessed by means of tensile fracture tests of cracked wires. A fatigue crack was transversally propagated from the wire surface. The damage tolerance curve of the wires results from the empirical failure load when given as a function of crack depth. As a consequence of cold drawing, the wire microstructure is orientated along its longitudinal axis and anisotropic fracture behavior is found at macrostructural level at the tensile failure of the cracked specimens. An in situ optical technique known as video image correlation VIC-2D was used to get an insight into this failure mechanism by tensile testing transversally fatigue cracked plañe specimens extracted from the cold-drawn wires. Additionally, the experimentally obtained damage tolerance curve of the cold-drawn ferritic-austenitic stainless steel wires is compared with that of the two types of high strength eutectoid wires currently used as prestressing steel for concrete. An elementary plástic collapse model for tensile failure of surface cracked wires is used to assess the damage tolerance curves.
Resumo:
The present investigation addresses the overall and local mechanical performance of dissimilar joints of low carbon steel (CS) and stainless steel (SS) thin sheets achieved by laser welding in case of heat source displacement from the weld gap centreline towards CS. Microstructure characterization and residua! strain scanning, carried out by neutron diffraction, were used to assess the joints features. It was found that the heat source position influences the base metals dilution and the residua! stress field associated to the welding process; the transverse residual stress is smaller than for the longitudinal component, of magnitudes close to the parent CS yield strength. Furthermore, compressive transverse residual stresses were encountered at the SS-weld interface. The tensile behavior of the joint different zones assessed by using a video-image based system (VIC-2D) reveals that the residual stress field, together with the positive difference in yield between the weld metal and the base materials protects the joint from being piastically deformed. The tensile loadings of flat transverse specimens generate the strain localization and failure in CS, far away from the weld.En este trabajo se exponen los resultados de una investigacion sobre el comportamiento mecanico de soldaduras disimiles acero inoxidable-acero al carbono, realizadas para unir chapas delgadas, desplazando la fuente de calor del eje longitudinal de la union soldada por laser sobre el acero al carbono. Se han determinado las caracteristicas microestructurales de la union soldada, las tensiones residuales generadas (mediante difraccion de neutrones) y las curvas tension-deformacion locales y globales, mediante medidas locales de deformacion empleando el sistema VIC-2D "video image correlation". El desplazamiento de la fuente de calor infiuye en la dilution de los metales base y el campo de tensiones residuales asociado al proceso de soldeo; las tensiones residuales medidas en direction longitudinal se aproximan al limite elastico del acero al carbono, mientras que las tensiones residuales transversales son menores, e incluso de compresion. El ensayo a traccion de la union soldada revela que las tensiones residuales y la diferencia de limite elastico entre los metales base y la soldadura propician que la rotura se produzca por inestabilidad plastica del acero al carbono, lejos de la soldadura, sin que la union plastifique.
Resumo:
El objeto del presente Proyecto de Ampliación del Puerto Deportivo de Almería ha consistido en definir pormenorizadamente la alternativa escogida en el Estudio Previo de Soluciones; y así hacer posible la construcción de la obra, ya que en él se detallan dimensiones, precios, plazos y funcionalidad. Se redacta el presente proyecto para dar solución a la demanda de amarres de embarcaciones de recreo existente en el Puerto de Almería.
Resumo:
El objetivo de la obra será la construcción de un viaducto que de continuidad a la autovía de Navarra A-15 cuando llega a la rivera del Duero. Esta construcción deberá cumplir unas determinadas características e integrarse en el carácter general de la obra. El tramo de autovía objeto del presente proyecto es necesario por una parte para completar la circunvalación sur de Soria (autovía del Duero A-11) y por otra como parte integrante de la futura autovía Medinaceli-Soria-Tudela (autovía de Navarra A-15).
Resumo:
A través de simulación se estudia el proceso de llegada y servicio de buques en las terminales del puerto de Valencias: Marítima Valenciana CT (terminal pública) y MSC CT (terminal dedicada). Se analizan las variables: “productividad del muelle (TEUs/m)”, “grado de ocupación”, “tiempos de espera”, “número de puestos de atraque” y “Probabilidad de que en un instante determinado se encuentren “n” buques en el sistema de atraque”.
Resumo:
El objeto de la estructura proyectada es el de salvar la vía de ferrocarril y comunicar las poblaciones de Formiguiero y Poboanza actualmente sin conexión por carretera. A lo largo del presente documento se describirán todos los condicionantes a los que ha estado sometido el proyecto y las decisiones estudiadas y tomadas referentes al diseño y cálculo de la estructura.
Resumo:
El presente documento pretende definir las obras e instalaciones necesarias para depurar las aguas de la cuenca este de Gijón. Con él se definirán las labores de construcción y explotación inicial de las obras de la estación depuradora de aguas residuales este de Gijón. La actuación se ubica en la zona costera al este de concejo de Gijón, entre el río Piles como límite occidental del ámbito de estudio, y el arroyo de la Ñora como límite oriental del mismo, estando al norte de la carretera N-632. El término municipal donde se localiza es Gijón, provincia de Asturias y Comunidad Autónoma del Principado de Asturias. Las obras descritas en el proyecto consisten en la construcción de una E.D.A.R. para depurar 225.000 habitantes equivalentes. Se conserva el pretratamiento existente y se incluye un tratamiento secundario con nitrificación-desnitrificación y decantación secundaria. La línea de fangos consistirá en espesadores más digestión anaerobia. En el presente documento se analizarán con detalle todos los parámetros necesarios para la definición de la E.D.A.R.
Resumo:
En el presente trabajo se presenta un estudio teórico y experimental de la determinación de la resistencia a tracción de materiales frágiles a partir de la técnica experimental de spalling. Se utilizan diferentes metodologías propuestas por varios autores para determinar la resistencia a tracción por spalling y se lleva a cabo un estudio mediante simulaciones numéricas de las diversas variables que influyen en este tipo de ensayos. Además, se realiza una campaña experimental de ensayos a una alúmina del 99,5% de pureza cuyos resultados son utilizados para la determinación de la resistencia a tracción de este material a partir de tres métodos diferentes propuestos por varios autores. Se expone el estudio y comparación de los resultados experimentales obtenidos de resistencia a tracción de la alúmina empleando técnicas de fotografía a alta velocidad y un sistema de correlación digital de imágenes. Los resultados muestran que la resistencia a tracción obtenida difiere en función de las diferentes metodologías propuestas.A theoretical and experimental study of the tensile strength of brittle materials using the experimental procedure of spalling of long bars is presented in this article. Different methodologies proposed by several authors are used to obtain the tensile strength of Al2O3 monolithic ceramic. The hypotheses needed for the experimental set-up are also checked, and the requirements of the set-up and the variables are also studied by means of numerical simulations. An experimental campaign has been carried out including high speed video and a digital image correlation system to obtain the tensile strength of alumina. Finally, a comparison of the test results provided by three different methods proposed by different authors are presented. The tensile strength obtained from three different methods on the same specimens provides different results.