Abastecimiento de una urbanización singular por medio de energías renovables

Una vez calculadas las necesidades energéticas de la urbanización, se calculan las aportaciones de diferentes fuentes de energías renovables: energía fotovoltaíca, energía eólica y energía por biomasa

Abastecimiento de una urbanización singular por medio de energías renovables

Una vez calculadas las necesidades energéticas de la urbanización, se calculan las aportaciones de diferentes fuentes de energías renovables: energía fotovoltaíca, energía eólica y energía por biomasa

Construcción y control de una maqueta Puente Colgante

El objeto de este Trabajo Fin de Grado ha sido recrear el funcionamiento básico del Puente Colgante de Vizcaya mediante el uso de la plataforma Lego Mindstorms principalmente. El trabajo ha incluido el estudio de viabilidad, el diseño previo, la construcción del Puente y su control. Para realizar el diseño previo se ha utilizado el software AutoDeskFusion 360. En cuanto a la construcción se refiere, los elementos utilizados han sido diversos, incluyendo piezas de Lego, barras Tetrix y materiales adicionales. Para el control del Puente, la programación se ha llevado a cabo mediante Bricx Command Center con NXC, un lenguaje de programación similar a C.Gradu AmaierakoL an honen helburua Bizkaiko Zubiaren funtzionamendua islatzea izan da, batik bat Lego Mindstroma kit-aren laguntzaren bidez. Lanaren osotasunean hiru zati nagusitan banatu da: aurretiko diseinua, maketaren eraikuntza eta zubia beraren kontrola. Aurretiko diseinua aurrera eramateko AutoDeskFusion 360 softwarea erabili da. Eraikuntzari dagokionez, elementu erabiliak hainbat izan dira, hala nola Lego piezak, Tetrix-ko barrak eta eskulanetarako hainbat material gehigarri. Kontrola BricxCommand Center softwarearen bidez eraman da, NXC programazioa erabiliz, C programazio lengoaiaren antzeko programazioa.The purpose of this Final Degree P roject has been to recreate in scale the Suspension B ridge of Bis cay by using mainly the Lego Mindstorms kit. The work has included a previous design, the construction of the bridge and its respective control. The previous design has been carried out by AutoDeskFusion 360 software. As far as the construction is concerned, diverse elements have been used , including pieces of Lego, Tetrix bars and additional material s . In order to control the bridge, programming has been carried out by Bric x Command Centre software , using NXC, a programming language similar to C with minor modifications

Improving surface integrity when drilling CFRPs and Ti-6Al-4V using sustainable lubricated liquid carbon dioxide

In the quest for decreasing fuel consumption and resulting gas emissions in the aeronautic sector, lightweight materials such as Carbon Fiber Reinforced Polymers (CFRPs) and Ti-6Al-4V alloys are being used. These materials, with excellent weight-to-strength ratios, are widely used for structural applications in aircraft manufacturing. To date, several studies have been published showing that the use of metalworking fluids (MWFs), special tool geometries, or advanced machining techniques is required to ensure a surface quality that meets aerospace component standards. Conventional MWFs pose a number of environmental and worker health hazards and also degrade the mechanical properties of CFRPs due to water absorption in the composite. Therefore, a transition to more environmentally friendly cooling/lubrication techniques that prevent moisture problems in the composite is needed. This research shows that lubricated LCO2 is a viable option to improve the quality of drilled CFRP and titanium aerospace components compared to dry machining, while maintaining clean work areas. The results show that the best combination of tool geometry and cooling conditions for machining both materials is drilling with Brad point drills and lubricated LCO2. Drilling under these conditions resulted in a 90 % improvement in fiber pull-out volume compared to dry machined CFRP holes. In addition, a 33 % reduction in burr height and a 15 % improvement in surface roughness were observed compared to dry drilling of titanium

Sensitivity Analysis of Various Geometries of PCD and Cemented Tungsten Carbide Cutting Tools during the Milling of GFRP Composite

Although much research has been carried out in the field of the milling of GFRP (Glass Fibre Reinforced Polymer) composites, the complexity of the process is such that it is still not mastered in many industrial cases. The current work is aimed at studying the influence of three different geometries of PCD (PolyCrystalline Diamond) and cemented tungsten carbide cutting tools during the up-milling of GFRP composites at fixed cutting conditions (vc = 502 m/min and vf = 420 mm/min). Delamination, cutting forces and tool wear are compared at the fresh and worn states, and the correlation between the lifespan and the cost of the cutting tool is analysed. The main wearing phase of the tools was performed under the conditions of production in the facilities of a company (Sobelcomp, Loncin, Belgium). The results indicate that the PCD tool with the straight edge, inclined peripheral tooth shape produces the smallest total cutting force and less delamination (shortest and lowest number of delaminated fibres) at both fresh and worn states. Moreover, the grinding ability of PCD makes the cutting tool cost per part lower than for cemented carbide. The PCD tool is therefore the best option to mill GFRP parts

Prediction of Surface Roughness of SLM Built Parts after Finishing Processes Using an Artificial Neural Network

A known problem of additive manufactured parts is their poor surface quality, which influences product performance. There are different surface treatments to improve surface quality: blasting is commonly employed to improve mechanical properties and reduce surface roughness, and electropolishing to clean shot peened surfaces and improve the surface roughness. However, the final surface roughness is conditioned by multiple parameters related to these techniques. This paper presents a prediction model of surface roughness (Ra) using an Artificial Neural Network considering two parameters of the SLM manufacturing process and seven blasting and electropolishing processes. This model is proven to be in agreement with 429 experimental results. Moreover, this model is then used to find the optimal conditions to be applied during the blasting and the electropolishing in order to improve the surface roughness by roughly 60%

Heat transferred to the workpiece based on temperature measurements by IR technique in dry and lubricated drilling of Inconel 718

In manufacturing aeronautical critical components, such as turbine discs commonly made of Inconel 718, surface integrity is crucial to ensure their fatigue life. Among the machining processes used, the drilling operation is one of the most critical as overheating can occur causing thermal damage to the hole. The amount of heat dissipated could determine the nature of deformation in the machining of Inconel 718. Nevertheless no detailed studies have determined experimentally the differences between the fractions of heat transferred to the workpiece (β) for dry and lubricated drilling. In this context, the thermal and mechanical loads (measured by IR technique and a piezoelectric dynamometer) affecting the drilling of Inconel 718 have been studied. Four different cutting conditions both in dry and lubricated conditions were tested. In order to obtain β, the study presents a model based on a new experimental method. The maximum β values were achieved in the unlubricated tests (around 0.20). By contrast, in the lubricated tests β range from 0.065 to 0.078. Therefore the fraction of heat conducted to the workpiece show maximum differences of 72% and minimum of 57% depending on the application or not application of coolant. Additionally, the obtained trends of β relative to Peclet number (that is dependent on the cutting speed, feed and drill diameter) are shown

Local Air pollution and global climate change taxes: a distributional analysis for the case of Spain.

Global climate change measures are difficult to implement. In this context, local air pollution measures may play an important role in the political agenda since their effects are felt more immediately by citizens. Distributional implications are one of the main barriers for implementing environmental policies. This paper explores the distributional implications of air pollution taxes and compares them to climate change taxes. For the comparison, both tax schemes were set to yield the same revenue. Methodologically, the study uses a top down approach linking a macro model to a micro model. We find that taxes on local air pollutants are more regressive than those levied on CO2. This is because the goods implicitly taxed have a greater weight in the consumer basket of low-income groups, even if the tax revenues are recycled. Furthermore, the revenue-neutral recycle scheme increases both taxes efficiency, but, at the same time, can increase regressivity

Enhancing surface integrity of A7050-T7451 aluminium alloy by pneumatic machine hammer peening

Aerostructures withstand cyclic mechanical loads and therefore, their design must fulfil surface integrity and fatigue strength requirements. This paper studies the effect of pneumatic machine hammer peening on surface integrity of 7050-T7451 aluminium alloy. Specimens were hammer peened using two different stepover distances (0.07 and 0.35 mm) and initial offset (0.3 and 0.5 mm). A Kistler dynamometer was used to measure the forces generated by hammer peening. Then, the surface topography, residual stresses and microstructural damage of the specimens were characterised. The results demonstrate that the magnitude of residual stresses and the thickness of the affected layer increases when reducing the stepover distance, while surface roughness reduces. Additionally, none of the tested conditions produced microstructural defects. These findings suggest that pneumatic hammer peening is an additional process to manufacture thin-walled structural aluminium alloy components

Effect of Post-Processing Treatment on Fatigue Performance of Ti6Al4V Alloy Manufactured by Laser Powder Bed Fusion

Fatigue properties of parts are of particular concern for safety-critical structures. It is well-known that discontinuities in shape or non-uniformities in materials are frequently a potential nucleus of fatigue failure. This is especially crucial for the Ti6Al4V alloy, which presents high susceptibility to the notch effect. This study investigates how post-processing treatments affect the mechanical performance of Ti6Al4V samples manufactured by laser powder bed fusion technology. All the fatigue samples were subjected to a HIP cycle and post-processed by machining and using combinations of alternative mechanical and electrochemical surface treatments. The relationship between surface properties such as roughness, topography and residual stresses with fatigue performance was assessed. Compressive residual stresses were introduced in all surface-treated samples, and after tribofinishing, roughness was reduced to 0.31 ± 0.10 µm, which was found to be the most critical factor. Fractures occurred on the surface as HIP removed critical internal defects. The irregularities found in the form of cavities or pits were stress concentrators that initiated cracks. It was concluded that machined surfaces presented a fatigue behavior comparable to wrought material, offering a fatigue limit superior to 450 MPa. Additionally, alternative surface treatments showed a fatigue behavior equivalent to the casting material.This research was funded by the Departamento de Desarrollo Económico, Sostenibilidad y Medio Ambiente of the Basque Government (ELKARTEK 2022 KK-2022/00070), by the Departamento de Desarrollo Económico y Competitividad of the Basque Government (ELKARTEK 2019 KK-2019/00077) and by the European Union (project TIFAN, JTI-CS-2013-1-ECO-01-066)