Integrated series active filter for aerospace flight control surface actuation

The paper investigates integrated series active filters to satisfy aircraft power quality benchmarks and underlying design compromises. Advantages include reduced component count and retrofitting capability. Further insights into the merits of the proposed solution are included, along with representative results from a prototype system

The influence of joints and composite floor slabs on effective tying of steel structures in preventing progressive collapse

The event of the terrorist attack at 11th September 2001 in the USA has attracted increasing attention of researchers and engineers on progressive collapse of structures. It has gradually become a general practice for engineers to consider progressive collapse resistance in their design. In this paper, progressive collapse of steel frames with composite floor slabs is simulated by the finite element method. The numerical results are compared with test results. The influence of the joints and the concrete slabs on the effective tying of steel beams is investigated through parametric studies. From the analysis, methods of preventing progressive collapse that can be considered in design and when retrofitting existing structures are proposed. The results show that retrofitting a structure with pre-stressed steel cables and an increase of crack resistance in the concrete near joints can effectively improve effective tying of a structure, which results in an enhanced structural capacity in preventing progressive collapse

Seismic analyses of a R/C building: study of a retrofitting solution

The preliminary experimental results from the tests on a 4-storey R/C frame structure are presented and discussed. The full-scale model is representative of the common practice of 40~50 years ago in most south European countries. Special attention is devoted to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands

OptEEmAL: Decision-Support Tool for the Design of Energy Retrofitting Projects at District Level

Designing energy retrofitting actions poses an elevated number of problems, as the definition of the baseline, selection of indicators to measure performance, modelling, setting objectives, etc. This is time-consuming and it can result in a number of inaccuracies, leading to inadequate decisions. While these problems are present at building level, they are multiplied at district level, where there are complex interactions to analyse, simulate and improve. OptEEmAL proposes a solution as a decision-support tool for the design of energy retrofitting projects at district level. Based on specific input data (IFC(s), CityGML, etc.), the platform will automatically simulate the baseline scenario and launch an optimisation process where a series of Energy Conservation Measures (ECMs) will be applied to this scenario. Its performance will be evaluated through a holistic set of indicators to obtain the best combination of ECMs that complies with user's objectives. A great reduction in time and higher accuracy in the models are experienced, since they are automatically created and checked. A subjective problem is transformed into a mathematical problem; it simplifies it and ensures a more robust decision-making. This paper will present a case where the platform has been tested.This research work has been partially funded by the European Commission though the European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No 680676. All related information to the project is available at https://www.opteemal-project.eu

Retrofitting the Brazilian Biodiesel Programme: Implications for Policy Design

In the context of oil price volatility and the need to reduce carbon emissions, biofuels are an emerging area of interest for many developing nations as alternative energy sources that, in some instances, can also enhance livelihoods in deprived agricultural areas. There are, however, a number of questions on this front: is it economically and environmentally feasible to incorporate small-scale family farmers into biofuel value chains? Can the production of biofuel feedstocks complement rather than compete with food crops? The experience of Brazil, a pioneer in the adoption of a socially inclusive approach to the production of feedstocks for biodiesel, has elicited much interest. This Policy Research Brief seeks to take stock of recent institutional developments and draw lessons as part of an ongoing learning process in an area where there are still no obvious sustainable business models or easy pathways to foster the inclusion of small-scale farmers. The Brief suggests that incorporation into the biodiesel value chain is both feasible and productive for family farmers. But the extent of the engagement required of intermediaries can be significant in the early stages of the programme in underserviced areas, particularly where farmers are dispersed and have not been extensively involved with market processes. Those embarking on these programmes thus have to consider such a production-support role. Further, the Brief suggests that intercropping (castor and beans, for example) can mitigate the food-fuel tradeoffs. However, the choice of optimal feedstocks from the point of view of equity and sustainability remains an open question.Retrofitting the Brazilian Biodiesel Programme: Implications for Policy Design

Dynamic nonlinear analyses for the 4-storey infilled R/C frame: study of a retrofitting solution

A research project on assessment and retrofitting of R/C frame structures is currently being developed under the research programme of the ICONS TMR-research network. This paper presents and discusses the preliminary experimental results from a 4-storey bare frame representative of the common practice of 40~50 years ago in most south European countries and devotes special attention to the study of a retrofitting solution based on bracing and rubber dissipaters, which intends to increase stiffness and damping reducing consequently the earthquake deformation demands.O estudo aqui apresentado concentra-se numa solução de reforço de um pórtico utilizando contraventamentos (k-bracing) com perfis de aço em conjunto com elementos elastoméricos de dissipação. Os resultados das análises não lineares da estrutura com e sem alvenaria e com reforço são apresentados e discutidos. Na segunda parte da comunicação apresentam-se os resultados experimentais já disponíveis e discute-se o problema da modelação recorrendo aos resultados experimentais e comparando os resultados obtidos com diferentes tipos de modelos

Experimental assessment and retrofit of full-scale models of existing RC frames

PSD tests on two full-scale models of existing non-seismic resisting RC frame structures are described. The testing program covered several aspects, namely assessment of seismic performance of existing frames without and with infill panels, retrofitting of the bare frame using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and retrofitting of the frame using K-bracing with shear-link dissipators. The main results from the tests are summarized and discussed and the conclusions are drawn. The tests on the bare frame have shown how vulnerable are existing structures constructed in the 60’s and the beneficial effects of infill panels were confirmed from the tests on the infilled frame. Important improvements, in terms of seismic performance, were achieved by the retrofitting of the frames. However, it was also confirmed that strengthening of the existing infill panels in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the external columns

Revitalization of Cracked Flexural Members using Retrofitting and Synthetic Wrapping

The modification of the Indonesia earthquake code SNI 2002 to SNI 2012 resulted in a significantly higher performance demand. The basics of these amendments lay in the re-zoning of earthquake maps, and the consideration of the earthquake influence to gravity loads. Members designed based on the SNI 2002 most likely will result in failure under future earthquakes. A reinforcement method based on the ACI 440 provision was conducted on cracked flexural members. The tensile reinforcement of these members has yielded and was neglected in the design. The tensile strains and stresses were further carried by the synthetic wraps applied to the tensile concrete fibers. The shear capacity of the member was enhanced by confinement of the member using the same synthetic wrap. Prior to wrap application, the members were straightened and retrofitted with an epoxy resin injection. The member was tested using a one-point-loading system to simulate a maximum bending moment in combination with maximum shear forces. The load-displacement responses and the ultimate load carrying capacity under monotonic incremental loading were recorded. It was found that this method will provide a solution for revitalization of cracked members in bending, and offer a solution to the design code alterations. © 2017 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the organizing committee of SCESCM 2016

Issues of energy retrofitting of a modern public housing estates. The ‘Giorgio Morandi’ complex at Tor Sapienza, Rome, 1975-1979

Energy retrofitting of historical residential buildings represents today an interesting challenge of the building sector. This is true especially in Italy where great part of the national buildingstock dates back to pre-modern and modern times and, especially, to the decades between the 1960s and the 1980s. Most of these buildings, in fact, offerthermal performances that are inadequate to current requirements in terms of energy efficiency, human comfort as well as to seismic safety. This study focuses on the energy retrofitting of public housing estatessuch as the“Giorgio Morandi” complex at Tor Sapienza in Rome. The upgrading of this complex is outlined, taking into account issues of energy saving but, also, constraints related to the historical values of the buildings. Intervention options able to improve energy efficiency are therefore foreseeable only in strict observance of cultural heritage values, which entails a deep analysis and survey of the existence in order to identify respectful, correct and feasiblesolutions