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Terraces, as outdoor extensions of food and beverage businesses located in the public realm, have very high potential to activate the streetscape, bring people together and improving urban experiences. Among the consequences of the current COVID-19 pandemic are the recommendations of maximizing outdoor environments when conducting human interactions. Therefore, outdoor eating has dramatically increased throughout the world, with terraces becoming a radical urban change in many streetscapes. The urgency of the situation, and rapid implementation of these changes, has revealed some aspects of this phenomenon that should be considered when adapting the regulations to this new reality. However, the research on their functioning and impact is limited. Additionally, although energy consumption in the architectural and urban field is considered fundamental, research has rarely addressed small business outdoor spaces, placing the focus instead on residential heating or public lighting. This study focuses on the intersection of these two gaps by analyzing a set of terraces in Barcelona and estimating the power installed in their outdoor heating devices. The goal is to determine the potential energy consumed, contrast it with other values more commonly used when researching architectural energy consumption and point out the lack of sustainability of these approaches to providing comfort. The calculations show that the installed power in Barcelona terraces is significant and, when estimating potential consumption, it presents values higher that the average heating consumption of residential units in Spain. These results support two main conclusions: first, the relevance of addressing the means of providing comfort in outdoor urban spaces due to the high magnitude of their potential energy consumption; second, the importance of adapting those systems to outdoor conditions, understanding the needs of the occupants and the limitations of the environment in order to develop sustainable solutions that provide comfort without attempting to heat the air of the street.
Carlos Alonso-Montolio; Gloria Serra-Coch; Antonio Isalgue; Helena Coch. The Energy Consumption of Terraces in the Barcelona Public Space: Heating the Street. Sustainability 2021, 13, 865 .
AMA StyleCarlos Alonso-Montolio, Gloria Serra-Coch, Antonio Isalgue, Helena Coch. The Energy Consumption of Terraces in the Barcelona Public Space: Heating the Street. Sustainability. 2021; 13 (2):865.
Chicago/Turabian StyleCarlos Alonso-Montolio; Gloria Serra-Coch; Antonio Isalgue; Helena Coch. 2021. "The Energy Consumption of Terraces in the Barcelona Public Space: Heating the Street." Sustainability 13, no. 2: 865.
In recent years, many software have appeared on the market to evaluate different parameters of lighting. Since the digital image has demonstrated the usefulness of measuring the luminances of surfaces, there are different software that help to evaluate the contrast of surfaces luminance. This paper presents the evaluation of three lighting software in three different lighting situations. Firstly, Aftab Alpha software requires the use of other sophisticated equipment such as luminance meter and reflex camera. Secondly, Fusion Optix software is an application easy to use because it works with a high dynamic range image from smartphones. Finally, Lumin software which reads the content of pixel-to-pixel picture to determine the luminance at each point of a scene is studied. Comparative measures serve to find the differences between the results of software analysis, the actual luminances of surfaces and different light intensities of spaces. This evaluation allows defining advantages and disadvantages of the use of three different software according to the light intensities of spaces. The study suggests that for spaces with low light intensity, the Aftab Alpha software and the Lumin software have a closer correspondence to the measurements. Concerning medium and high light intensity spaces, the Aftab Alpha software presents values near to reality.
Eduardo Espinoza Cateriano; Judit Lopez-Besora; Antonio Isalgue Buxeda; Helena Coch Roura; Isabel Crespo Cabillo. Evaluation of Three Lighting Software in the Use of Different Light Intensity Spaces. Blockchain Technology and Innovations in Business Processes 2020, 419 -429.
AMA StyleEduardo Espinoza Cateriano, Judit Lopez-Besora, Antonio Isalgue Buxeda, Helena Coch Roura, Isabel Crespo Cabillo. Evaluation of Three Lighting Software in the Use of Different Light Intensity Spaces. Blockchain Technology and Innovations in Business Processes. 2020; ():419-429.
Chicago/Turabian StyleEduardo Espinoza Cateriano; Judit Lopez-Besora; Antonio Isalgue Buxeda; Helena Coch Roura; Isabel Crespo Cabillo. 2020. "Evaluation of Three Lighting Software in the Use of Different Light Intensity Spaces." Blockchain Technology and Innovations in Business Processes , no. : 419-429.
Renewable energy polygeneration systems are a viable alternative to fossil-fuel based systems, but storage solutions may be necessary when aiming for high sustainability and autonomy. As each storage technology has different strengths and weaknesses, combinations of various storage solutions may lead to better techno-economic performance than singular approaches. To this purpose, an optimization model including a novel dispatch control strategy for a hybrid energy storage system (HESS) is proposed, which uses biogas for long-term and batteries for short-term storage. The model optimizes for minimum lifetime costs while exploiting the biomass resources with maximum efficiency and quantifying the additional solar and battery capacities needed. It is applied in a case study with an innovative biomass-based polygeneration system in a rural locality of Bolivia to serve electricity, potable water, and bio-slurry as fertilizer. The results indicate that even with maximized efficiency of the biomass resource conversion, large PV and battery capacities are necessary to satisfy the electricity demand of the locality. Despite of the high investment costs, the biomass-based polygeneration system would cost 22% less over the project lifetime than the fossil-fuel based reference system while being less dependent on fuel price changes. It would also reduce CO2-emissions by over 98%.
Moritz Wegener; J. Villarroel Schneider; Anders Malmquist; Antonio Isalgue; Andrew Martin; Viktoria Martin. Techno-economic optimization model for polygeneration hybrid energy storage systems using biogas and batteries. Energy 2020, 218, 119544 .
AMA StyleMoritz Wegener, J. Villarroel Schneider, Anders Malmquist, Antonio Isalgue, Andrew Martin, Viktoria Martin. Techno-economic optimization model for polygeneration hybrid energy storage systems using biogas and batteries. Energy. 2020; 218 ():119544.
Chicago/Turabian StyleMoritz Wegener; J. Villarroel Schneider; Anders Malmquist; Antonio Isalgue; Andrew Martin; Viktoria Martin. 2020. "Techno-economic optimization model for polygeneration hybrid energy storage systems using biogas and batteries." Energy 218, no. : 119544.
The use of vegetation in urban environments is a design strategy which brings thermal benefits at street level, especially in warm climates in hot periods. Urban environments integrate different types of vegetation that modify the thermal composition of public space and therefore, the mean radiant temperature (MRT). The characteristics and surface temperature of the surrounding elements such as vegetation determine the value of MRT. In this study, the temperature of a concrete wall and a wall covered with vegetation are compared under the same conditions. The objective is to determine the influence of vertical vegetation in pedestrians’ thermal perception in a hot period. To this end, a sequence of thermographic pictures was taken with temperature measurements on specific points of both materials. Also, measurements of air temperature, bulb globe temperature and relative humidity were carried out during the same period. The sequence of infrared thermography shows the different temperatures between vegetation and concrete under direct solar radiation, which reaches up to 10 °C in the central hours of the day. The variation of temperature along the measurement sequence is also different in both cases. According to that, vegetation does not reach a temperature as high as other materials such as concrete in hot periods, which contributes to decreasing pedestrians’ heat perception.
Judit Lopez-Besora; Carlos Alonso-Montolio; Antonio Isalgue; Sayonara Benitez. The Role of Vegetation in Urban Comfort: Surface Temperature Assessment at Street Level. Blockchain Technology and Innovations in Business Processes 2020, 539 -548.
AMA StyleJudit Lopez-Besora, Carlos Alonso-Montolio, Antonio Isalgue, Sayonara Benitez. The Role of Vegetation in Urban Comfort: Surface Temperature Assessment at Street Level. Blockchain Technology and Innovations in Business Processes. 2020; ():539-548.
Chicago/Turabian StyleJudit Lopez-Besora; Carlos Alonso-Montolio; Antonio Isalgue; Sayonara Benitez. 2020. "The Role of Vegetation in Urban Comfort: Surface Temperature Assessment at Street Level." Blockchain Technology and Innovations in Business Processes , no. : 539-548.
One of the main responsible for the heat flux between the exterior and the interior space is the building’s envelope. In order to achieve better interior thermal comfort conditions, it is necessary to control heat gains and losses through it. The aim of this paper is to analyze the role of the façade and the roof in a habitable volume exposed to the celestial vault and their energetic behavior due to the conductive and the radiative exchanges. A volume with no windows, no thermal insulation, no internal gains and with an approximate sky view factor (SVF) of 80% was used as the study case. The case study was modeled on a digital simulation program. Then it was calibrated and validated with measurements of indoor temperature and relative humidity taken on site for approximately three years. Heat flux values were obtained from the simulation program. With the envelope heat flux analysis, it can be concluded that the roof is the enclosure of the envelope that has the greatest influence on the heat flux balance, consequently also on the indoor temperature behavior.
Natalia Ruiz-Llaneza; Carlos Alonso-Montolio; Antonio Isalgue; Helena Coch. Heat Flux Balance in Mediterranean Climates: Thermal Insulation Location in Building Enclosures. Blockchain Technology and Innovations in Business Processes 2020, 491 -501.
AMA StyleNatalia Ruiz-Llaneza, Carlos Alonso-Montolio, Antonio Isalgue, Helena Coch. Heat Flux Balance in Mediterranean Climates: Thermal Insulation Location in Building Enclosures. Blockchain Technology and Innovations in Business Processes. 2020; ():491-501.
Chicago/Turabian StyleNatalia Ruiz-Llaneza; Carlos Alonso-Montolio; Antonio Isalgue; Helena Coch. 2020. "Heat Flux Balance in Mediterranean Climates: Thermal Insulation Location in Building Enclosures." Blockchain Technology and Innovations in Business Processes , no. : 491-501.
As governments and companies struggle to meet their own objectives for the energy transition, more innovative social and technological measures are needed to reduce Greenhouse Gas (GHG) emissions. For this purpose, an assessment of an off-grid polygeneration system, which can serve the electric and cooling demand of a neighbourhood in Hermosillo, Mexico, has been conducted. Energy computations have been done, the energy demand of one dwelling has been measured to ascertain the correctness of the computations, and a demand model for the entire neighbourhood has been created. Based on the model, an off-grid polygeneration system has been designed, which uses a biodiesel engine, PV panels, and an absorption chiller. The system has been optimized for its economic performance and is compared to the currently used system. The results show that the polygeneration system with higher energy efficiency could reduce GHG emissions down to 14%. However, electricity in Hermosillo is heavily subsidized making it harder for innovative systems to compete. Moreover, even without the state subsidies to the end user, the polygeneration system has still a nearly 30% higher Net Present Cost (NPC) than the conventional system over its project lifetime of 20 years. Nonetheless, with precise political incentives and further advances in the applied technologies, small-scale renewable polygeneration systems could become cost-efficient alternatives in the near future.
Moritz Wegener; Carlos Lopez Ordóñez; Antonio Isalgué; Anders Malmquist; Andrew Martin. How Much Does It Cost to Go Off-Grid with Renewables? A Case Study of a Polygeneration System for a Neighbourhood in Hermosillo, Mexico. Blockchain Technology and Innovations in Business Processes 2019, 395 -405.
AMA StyleMoritz Wegener, Carlos Lopez Ordóñez, Antonio Isalgué, Anders Malmquist, Andrew Martin. How Much Does It Cost to Go Off-Grid with Renewables? A Case Study of a Polygeneration System for a Neighbourhood in Hermosillo, Mexico. Blockchain Technology and Innovations in Business Processes. 2019; ():395-405.
Chicago/Turabian StyleMoritz Wegener; Carlos Lopez Ordóñez; Antonio Isalgué; Anders Malmquist; Andrew Martin. 2019. "How Much Does It Cost to Go Off-Grid with Renewables? A Case Study of a Polygeneration System for a Neighbourhood in Hermosillo, Mexico." Blockchain Technology and Innovations in Business Processes , no. : 395-405.
The causal relation among building typology and building energy demand is a complex balance of climate, morphology, technology and use. The assessment of the relation between mass of building elements and energy demand in different housing typologies is the main goal of this study. A novel indicator, namely the Buildingmass, is introduced and tested in the Mediterranean climate region. Explorations on nine conventional housing typologies in Barcelona and Rome are carried out. Buildingmass evaluation is based on the calculation of the mass of building elements. Energy demand is assessed by modelling on multi-space dynamic thermal analysis tool. Our results point out that the Buildingmass has a strong relevance on energy, playing an important role in reducing heating and cooling demand in the Mediterranean city, as described by the proposed correlation (R2 = 0.88). Moreover, this indicator gives a more detailed characterisation of the housing stock of the Mediterranean city. The study aims at bridging the gap between urban physics and urban metabolism studies and fostering energy conservation measures for the built environment.
Michele Morganti; Anna Pages-Ramon; Helena Coch; Antonio Isalgue. Buildingmass and Energy Demand in Conventional Housing Typologies of the Mediterranean City. Sustainability 2019, 11, 3540 .
AMA StyleMichele Morganti, Anna Pages-Ramon, Helena Coch, Antonio Isalgue. Buildingmass and Energy Demand in Conventional Housing Typologies of the Mediterranean City. Sustainability. 2019; 11 (13):3540.
Chicago/Turabian StyleMichele Morganti; Anna Pages-Ramon; Helena Coch; Antonio Isalgue. 2019. "Buildingmass and Energy Demand in Conventional Housing Typologies of the Mediterranean City." Sustainability 11, no. 13: 3540.
Energy services are especially expensive on remote islands due to longer and more unstable fuel supply chains. In this paper, different renewable energy systems utilizing locally available biomass and solar energy are proposed as alternatives for a hotel resort on Neil Island, India. Based on local demand data, commercial information, and scientific literature, four cases are modelled with the simulation software HOMER and their economic, energetic, as well as ecological (3E) performances are compared. The robustness of each case configuration is tested with a sensitivity analysis. The results show that a biomass-based, solar-assisted combined cooling, heating, and power (CCHP) system offers an economic saving potential of more than 500,000 USD over twenty years and could decrease CO2 emissions by 365 t per year. When not applying CCHP measures, system performance is significantly worsened. A solar and battery-assisted diesel generator system shows similar economic outcomes as the CCHP system but worse ecological performance. Implementing the biomass-based CCHP system could improve the ecological footprint of the island, substantially decrease expenditure for the hotel owner, and generate a new source of income for surrounding farmers through biomass selling.
Moritz Wegener; Antonio Isalgué; Anders Malmquist; Andrew Martin. 3E-Analysis of a Bio-Solar CCHP System for the Andaman Islands, India—A Case Study. Energies 2019, 12, 1113 .
AMA StyleMoritz Wegener, Antonio Isalgué, Anders Malmquist, Andrew Martin. 3E-Analysis of a Bio-Solar CCHP System for the Andaman Islands, India—A Case Study. Energies. 2019; 12 (6):1113.
Chicago/Turabian StyleMoritz Wegener; Antonio Isalgué; Anders Malmquist; Andrew Martin. 2019. "3E-Analysis of a Bio-Solar CCHP System for the Andaman Islands, India—A Case Study." Energies 12, no. 6: 1113.
The light metal roof is one of the roof typologies most used in low latitude regions with warm and humid climates. The low installation cost is one of the benefits of this typology, however, they offer only low resistance to the heat flux. In order to analyse strategies to reduce the indoor overheating in this climates, this investigation addresses the impact of reflectivity and emissivity on the light metal roof thermal behaviour. The study was carried out with dynamic simulations, considering the climate of a city in the south coast of Ecuador (Santa Rosa, 3°27´S). This analysis has parameterized the interior surface temperature in function of the reflectivity and emissivity, which has been validated with the measurements of several samples with different radiative properties. The analysed samples show that the effect of the aging and the use of different paints have a higher impact on the increase in emissivity than on reflectivity. In conclusion, the results show that the radiative parameter with the highest influence on interior surface temperature reduction is emissivity.
Jefferson Torres-Quezada; Helena Coch; Antonio Isalgué. Assessment of the reflectivity and emissivity impact on light metal roofs thermal behaviour, in warm and humid climate. Energy and Buildings 2019, 188-189, 200 -208.
AMA StyleJefferson Torres-Quezada, Helena Coch, Antonio Isalgué. Assessment of the reflectivity and emissivity impact on light metal roofs thermal behaviour, in warm and humid climate. Energy and Buildings. 2019; 188-189 ():200-208.
Chicago/Turabian StyleJefferson Torres-Quezada; Helena Coch; Antonio Isalgué. 2019. "Assessment of the reflectivity and emissivity impact on light metal roofs thermal behaviour, in warm and humid climate." Energy and Buildings 188-189, no. : 200-208.
The growing demand for energy and the accelerating threats from climate change call for innovative and sustainable solutions to decrease dependency on fossil fuels. Biomass-based, small-scale Combined Cooling, Heating and Power (CCHP) systems are one of these solutions, because they can satisfy the energy demands of the consumer with enhanced flexibility, lower losses, less costs and less environmental pollution as compared to centralized facilities. Due to recent advances in several scientific subfields with relevance to small-scale CCHP, a rapidly increasing amount of literature is now available. Therefore, a structural overview is essential for engineers and researchers. This paper presents a review of the current investigations in small-scale CCHP systems covering biomass-fired concepts and solar extensions. To this end, critical system components are described and analysed according to their specific advantages and drawbacks. Recent case studies have been collected and key findings are highlighted according to each type of prime mover. The results indicate a scientific bias towards the economic viability of such systems and the need for real-life and experiment system data. However, the potential of biomass-fired CCHP systems and of such systems with solar extensions has clearly been recognised. Based on the results, future policy implementations should focus on fostering such systems in areas with high energy costs and to increase energy resilience in developed regions. Additionally research and industry applying novel prime mover technologies should be financially supported.
Moritz Wegener; Anders Malmquist; Antonio Isalgue; Andrew Martin. Biomass-fired combined cooling, heating and power for small scale applications – A review. Renewable and Sustainable Energy Reviews 2018, 96, 392 -410.
AMA StyleMoritz Wegener, Anders Malmquist, Antonio Isalgue, Andrew Martin. Biomass-fired combined cooling, heating and power for small scale applications – A review. Renewable and Sustainable Energy Reviews. 2018; 96 ():392-410.
Chicago/Turabian StyleMoritz Wegener; Anders Malmquist; Antonio Isalgue; Andrew Martin. 2018. "Biomass-fired combined cooling, heating and power for small scale applications – A review." Renewable and Sustainable Energy Reviews 96, no. : 392-410.
N. Cinca; A. Isalgué; C. Auguet; A. Concustell; I.G. Cano; Josep Maria Guilemany; F. Fauth. Ordering kinetics evaluation of FeAl powders. Intermetallics 2017, 91, 78 -85.
AMA StyleN. Cinca, A. Isalgué, C. Auguet, A. Concustell, I.G. Cano, Josep Maria Guilemany, F. Fauth. Ordering kinetics evaluation of FeAl powders. Intermetallics. 2017; 91 ():78-85.
Chicago/Turabian StyleN. Cinca; A. Isalgué; C. Auguet; A. Concustell; I.G. Cano; Josep Maria Guilemany; F. Fauth. 2017. "Ordering kinetics evaluation of FeAl powders." Intermetallics 91, no. : 78-85.
This work deals with daylighting for indoor quality atmospheres, considering building skins and side-views. We also tested the vision perception provided by highly glazed façades. Several Spanish restaurants were analyzed, and two were assessed and measured under outside midday high luminance. The selected pictures can be identified as restaurants via MIT Scene Recognition software and are used to demonstrate working, stressful, and socializing atmospheres. Light and vision detailed analysis was performed defining three workplanes—“table”, “person”, and “outside”—from the viewpoint of the user. The obtained DGP (daylight glare probability) for the first case (facing southeast) shows a higher glare probability than the second (facing north). In both restaurants, there is notable spatial contrast and high information content. If, in the overall perception, the adaptation from the intermediate workplane is considered, the DGP is lower than if only one workplane is considered. The conducted indicative survey shows that there is a high light contrast, and there are some undesirable visual elements. The studied fully glazed façades tend to provide fraught atmospheres. These would be useful for some stimulating activities; however, for calm restaurants that offer tasting menus with quality food, it seems that the studied fully glazed façades may not be suitable.
Urtza Uriarte; Rufino J. Hernández; Joan L. Zamora; Antonio Isalgue. Side-View Atmospheres under Outdoor Midday High Luminance. Buildings 2016, 6, 53 .
AMA StyleUrtza Uriarte, Rufino J. Hernández, Joan L. Zamora, Antonio Isalgue. Side-View Atmospheres under Outdoor Midday High Luminance. Buildings. 2016; 6 (4):53.
Chicago/Turabian StyleUrtza Uriarte; Rufino J. Hernández; Joan L. Zamora; Antonio Isalgue. 2016. "Side-View Atmospheres under Outdoor Midday High Luminance." Buildings 6, no. 4: 53.
Natural resources such as daylight and sunlight are highly appreciated in countries with prevailing overcast skies. Taking advantage of this scarce resource contributes to saving energy on artificial lighting. In contrast to northern, southern European cities are distinguished by a large number of days with direct sunlight caused by a propitious climate condition. While it is a positive issue in terms of energy availability, the abundance of it can be counterproductive if management measures are not taken. Apart from the thermal consequences, lighting penetration into buildings causes a great contrast between inside and outside. This is especially critical when the visual system does not have enough time to adapt, as happens at entrance areas. The aim of this study is to analyze the light contrast between these areas and the urban outside in sunny conditions. To attain this objective, light data from five entrance spaces and their contiguous streets were analyzed and measured. The results were divided into three zones in the visual scene, showing an increasing contrast from top to bottom of the visual field. It may be concluded that interventions applied to urban areas and building pavements can improve visual adaptation in the transition zone.
Judit Lopez-Besora; Glòria Serra-Coch; Helena Coch; Antonio Isalgue. Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue. Energies 2016, 9, 753 .
AMA StyleJudit Lopez-Besora, Glòria Serra-Coch, Helena Coch, Antonio Isalgue. Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue. Energies. 2016; 9 (9):753.
Chicago/Turabian StyleJudit Lopez-Besora; Glòria Serra-Coch; Helena Coch; Antonio Isalgue. 2016. "Daylight Management in Mediterranean Cities: When Shortage Is Not the Issue." Energies 9, no. 9: 753.
Energy is considered as a main influence on urban configurations. However, there is a difficulty on translating the city models based on theoretical renewable energy concepts into practical applications. This study considers the possibility of understanding this future model as a transformation of the existing urban centres. With this objective, a methodology to intervene in existing cities based on the study of solar access is developed. Therefore, an analysis of solar potential in relation with urban morphology is carried on through a simulation software in l’Eixample, a neighbourhood of Barcelona. The distribution of the sun factor in the different areas of the building blocks envelope displays possible morphological modifications that would facilitate solar energy collection. Consequently, the analytical method presented could be applied to regulate urban interventions with the aim of obtaining more solar energy based cities.
Alessandra Curreli; Glòria Serra-Coch; Antonio Isalgue; Isabel Crespo; Helena Coch. Solar Energy as a Form Giver for Future Cities. Energies 2016, 9, 544 .
AMA StyleAlessandra Curreli, Glòria Serra-Coch, Antonio Isalgue, Isabel Crespo, Helena Coch. Solar Energy as a Form Giver for Future Cities. Energies. 2016; 9 (7):544.
Chicago/Turabian StyleAlessandra Curreli; Glòria Serra-Coch; Antonio Isalgue; Isabel Crespo; Helena Coch. 2016. "Solar Energy as a Form Giver for Future Cities." Energies 9, no. 7: 544.
Antonio Isalgue; Carlota Auguet; Amadeu Concustell; Nuria Cinca. Microstructural effects of strain aging on NiTi pseudoelastic wires by synchrotron X-ray micro-diffraction. MATEC Web of Conferences 2015, 33, 03020 .
AMA StyleAntonio Isalgue, Carlota Auguet, Amadeu Concustell, Nuria Cinca. Microstructural effects of strain aging on NiTi pseudoelastic wires by synchrotron X-ray micro-diffraction. MATEC Web of Conferences. 2015; 33 ():03020.
Chicago/Turabian StyleAntonio Isalgue; Carlota Auguet; Amadeu Concustell; Nuria Cinca. 2015. "Microstructural effects of strain aging on NiTi pseudoelastic wires by synchrotron X-ray micro-diffraction." MATEC Web of Conferences 33, no. : 03020.
Antonio Isalgue; Hugo Soul; Alejandro Yawny; Carlota Auguet. Functional fatigue recovery of superelastic cycled NiTi wires based on near 100 °C aging treatments. MATEC Web of Conferences 2015, 33, 03019 .
AMA StyleAntonio Isalgue, Hugo Soul, Alejandro Yawny, Carlota Auguet. Functional fatigue recovery of superelastic cycled NiTi wires based on near 100 °C aging treatments. MATEC Web of Conferences. 2015; 33 ():03019.
Chicago/Turabian StyleAntonio Isalgue; Hugo Soul; Alejandro Yawny; Carlota Auguet. 2015. "Functional fatigue recovery of superelastic cycled NiTi wires based on near 100 °C aging treatments." MATEC Web of Conferences 33, no. : 03019.
Shape memory alloys are considered smart materials because of their singular thermo-mechanical properties, due to a thermoelastic martensitic transformation, enabling possible uses as actuators (because of mechanical recovery induced from temperature changes) and as dampers (because of hysteresis). NiTi wires for dampers in Civil Engineering had been characterized and tested in facilities. Guaranteed performance needs to know behavior during fatigue life and knowledge of effects in the event of extreme conditions, as eventual overstraining. In this work, we check the possibilities to absorb mechanical energy on the fatigue life depending on stress level and explore the consequences of overstraining the material during installation, the possibilities of partial healing by moderate heating, and some effects of over-stressing the wires. The mechanical energy absorbed by the unit weight of damper wire might be very high during its lifetime if maximum stresses remain relatively low allowing high fatigue life. We show also some results on NiTi wire working as an actuator. The lifetime mechanical work performed by an actuator wire can be very high if applied stresses are limited. The overstraining produces relevant “residual” deformation, which can be to some extent reversed by moderate heating at zero stress. The reason for the observed characteristics seems to be that when external high stresses are applied to an NiTi wire, it undergoes some plastic deformation, leaving a distribution of internal stresses that alter the shape and position of the macroscopic stress-strain transformation path.
Antonio Isalgue; Carlota Auguet; R. Grau; V. Torra; Núria Cinca; J. Fernandez. Behavior of NiTi Wires for Dampers and Actuators in Extreme Conditions. Journal of Materials Engineering and Performance 2015, 24, 3323 -3327.
AMA StyleAntonio Isalgue, Carlota Auguet, R. Grau, V. Torra, Núria Cinca, J. Fernandez. Behavior of NiTi Wires for Dampers and Actuators in Extreme Conditions. Journal of Materials Engineering and Performance. 2015; 24 (9):3323-3327.
Chicago/Turabian StyleAntonio Isalgue; Carlota Auguet; R. Grau; V. Torra; Núria Cinca; J. Fernandez. 2015. "Behavior of NiTi Wires for Dampers and Actuators in Extreme Conditions." Journal of Materials Engineering and Performance 24, no. 9: 3323-3327.
The SMA was studied for their macroscopic application in damping for civil engineering. The study is a synthesis and includes an outline of the models required for the SMA simulation and some case studies using the finite element analysis methods. This work is an overview that focuses in the mitigation of the oscillations in structures induced by earthquakes, and for a reduction of the oscillations amplitude in stayed cables under the action of rain, wind or traffic. The analysis needs the required conditions for each application determining the working conditions. The study includes the number of working cycles, the temperature effects and the cooling actions and, for instance, the action of the cycling frequency. The main target relates the appropriateness of the SMA for each purpose, and the suitability of the SMA device is always experimentally guaranteed. Furthermore, the applicability of the obtained results for SMA and the practical behavior of the SMA dampers were studied in international facilities. The paper includes appropriate suggestions for a correct preparation of the SMA dampers. This work outlines the effects of stress and temperature aging in NiTi, describes the particular structural effects between 18R and 6R, introduces a first attempt in the dynamic properties of the CuAlBe single crystals and summarizes some recent suggestions for damping using SMA.
V. Torra; Antonio Isalgue; F. C. Lovey; M. Sade. Shape memory alloys as an effective tool to damp oscillations. Journal of Thermal Analysis and Calorimetry 2015, 119, 1475 -1533.
AMA StyleV. Torra, Antonio Isalgue, F. C. Lovey, M. Sade. Shape memory alloys as an effective tool to damp oscillations. Journal of Thermal Analysis and Calorimetry. 2015; 119 (3):1475-1533.
Chicago/Turabian StyleV. Torra; Antonio Isalgue; F. C. Lovey; M. Sade. 2015. "Shape memory alloys as an effective tool to damp oscillations." Journal of Thermal Analysis and Calorimetry 119, no. 3: 1475-1533.
The thermo-mechanical properties of Shape Memory Alloys (SMA) as smart materials suggest their application as actuators, but also as dampers, thanks to the high damping properties during the hysteresis of the thermo-elastic martensitic transformation. Damping in civil engineering is needed to minimize earthquake effects on buildings, and also to limit the damage produced by wind or traffic induced oscillations in stayed cables in bridges. In this work, we explore the consequences of strain aging the material at moderate temperatures (100 °C). A quasi-static stress and temperature aging of NiTi SMA wires of 2.46 mm diameter was done at 373 K. The experimental measurements establish a monotonic effect related to the introduced strain. Aging under larger strains modifies the hysteretic shape and induces an increase in the maximal stress on the transformation from 600 MPa to 800-1000 MPa. Aging at 373 K under 7-8% strain, the effect was up to 200 MPa in three months and near 400 MPa in eight months. The modified stress-strain curves suggest potential application as dampers under larger summer-winter temperature changes, i.e., from 233 to 323 K.
A. Isalgue; Carlota Auguet; V. Torra; G. Carreras; F.C. Lovey. Effects of Strain Aging in NiTi SMA Wire for Dampers. Materials Today: Proceedings 2015, 2, S983 -S986.
AMA StyleA. Isalgue, Carlota Auguet, V. Torra, G. Carreras, F.C. Lovey. Effects of Strain Aging in NiTi SMA Wire for Dampers. Materials Today: Proceedings. 2015; 2 ():S983-S986.
Chicago/Turabian StyleA. Isalgue; Carlota Auguet; V. Torra; G. Carreras; F.C. Lovey. 2015. "Effects of Strain Aging in NiTi SMA Wire for Dampers." Materials Today: Proceedings 2, no. : S983-S986.
The aim of this work is to study the effect of the thermal cycling on the stability of SME and to follow the loss of SME as a result of DSC cycling. The structural evolution was examined by SEM, DSC and X-Ray diffraction using a heating holder that allows heating the samples. Different alloy compositions have been studied. There is a thermal degradation of the transformation because of the presence of equilibrium phases that change with cycling. A decrease of the transformation temperatures was found. Also the results show that the dependence of the amount of transformation with cycle number is not dependent of the composition for Ag contents from 4 to 15 wt%.
Javier Fernandez; Antonio Isalgue; R. Franch. Effect of Thermal Cycling on CuAlAg Shape Memory Alloys. Materials Today: Proceedings 2015, 2, S805 -S808.
AMA StyleJavier Fernandez, Antonio Isalgue, R. Franch. Effect of Thermal Cycling on CuAlAg Shape Memory Alloys. Materials Today: Proceedings. 2015; 2 ():S805-S808.
Chicago/Turabian StyleJavier Fernandez; Antonio Isalgue; R. Franch. 2015. "Effect of Thermal Cycling on CuAlAg Shape Memory Alloys." Materials Today: Proceedings 2, no. : S805-S808.