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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Konzept für die Einbeziehung des Digitalen Zwillings für zukünftige Retrofitmaßnahmen

Fuchs, Josef, Grau, Niklas, Welter, Jürgen 13 February 2024 (has links)
Die zunehmende Forderung an automatisierte Produktionsanlagen sich flexibel auf neue Situationen in der Produktion anpassen zu können, fordert innovative Konzepte. Dieser Beitrag stellt ein Retrofit- Konzept vor, welches bereits bei der Erstellung der Anlagen mit integriert werden kann, um somit zukünftig flexibel Teilbereiche austauschen zu können. Hierbei muss in den praxiserprobten Steuerungsablauf nicht direkt eingegriffen werden. Das vorliegende Konzept basiert auf einer Anforderungsanalyse und ist prototypisch umgesetzt.
32

Review and Evaluation of Reinforced Concrete Member Retrofit Methods

Sichko, Alexander, Sichko January 2017 (has links)
No description available.
33

Role of timber in the seismic resilience of existing URM buildings

Rizzi, Ermes 24 April 2020 (has links)
The main topic of the thesis is the role of timber in the seismic resilience of unreinforced masonry (URM) buildings. The research addressed both existing timber components that can be encountered in URM buildings and timber-based retrofit solutions. The work presented herein can be split into two main phases. In the first part of the research, the in-plane behavior of traditional wooden floors was analyzed by means of numerical static and dynamic simulations. Modelling strategies with different refinement levels were proposed and implemented to assess diaphragm in-plane strength and flexibility. Modelling was undertaken considering as-built diaphragms first and was then extended to diaphragms retrofitted by means of timber-based techniques. The influence of diaphragm construction details on their in-plane response was evaluated and timber-based retrofitting solutions were observed to be effective in mitigating in-plane diaphragm flexibility and in increasing in-plane diaphragm strength. The second part of the PhD work was dedicated to investigate new retrofit solutions for URM buildings based on the use of engineered timber panels mechanically connected to the masonry. The first step saw the experimental testing of different types of timber-to-masonry connections considering both screw-type fasteners and adhesive anchors. In the second stage, full-scale masonry walls were tested in the as-built, retrofitted and repaired configurations, highlighting the benefits of the proposed technique on the in-plane response of the masonry walls.
34

Recomendações para o uso de BIM 4D na gestão de empreendimentos habitacionais de retrofit

Souza, Fernanda Justin Chaves de January 2015 (has links)
Os empreendimentos de retrofit vem ganhando destaque dentro do segmento de construção habitacional, dado o aumento de idade do estoque existente. A gestão de empreendimentos de retrofit apresenta muitos desafios, principalmente quando a execução da obra ocorre em edificações ocupadas. Em geral, há muitos desafios ligados às perturbações causadas aos usuários destas edificações. Alguns estudos realizados indicam que o Building Information Modeling (BIM) tem contribuído para a gestão da produção de empreendimentos novos. Entretanto, no âmbito de retrofit, o BIM tem sido pouco explorado, principalmente quanto ao uso de modelagem 4D no processo de produção. O objetivo desta dissertação consiste em propor recomendações para o uso de BIM 4D na gestão da produção de empreendimentos habitacionais de retrofit. Tais recomendações tem como propósito auxiliar tomadores de decisão envolvidos na gestão deste tipo de empreendimento, particularmente no que se refere à identificação e minimização de perturbações que afetam os usuários finais durante a obra. A estratégia de pesquisa adotada neste trabalho foi a Design Science Research, na qual se buscou o desenvolvimento de um conjunto de prescrições para um problema real. Considerando o caráter exploratório desta pesquisa e algumas limitações no estudo empírico, a fase de compreensão do problema teve maior destaque do que a fase de implementação da solução. O estudo empírico foi realizado em uma obra na Irlanda do Norte, sendo que diferentes cenários de execução foram propostos para a execução da obra, utilizando BIM 4D para a identificação e redução das perturbações para os usuários finais. Entre as principais contribuições do trabalho, pode-se destacar a caracterização das perturbações causadas durante as obras de retrofit quando ocupadas pelos usuários, assim como o uso de cenários simulados com o uso de BIM 4D, na análise de planos alternativos nas etapas de projeto e produção. / There has been a growing interest in retrofit projects in the house building sector, given the increasing age of the existing building stock. In general, retrofit projects bring a number of challenges, especially when works are carried out in occupied buildings. Much of these challenges are related to disruptions caused to occupiers. Previous studies have indicated that Building Information Modeling (BIM) has contributed substantially in production management for new projects. However, the application of BIM in retrofit has not been much explored, especially concerning the use of 4D modelling to simulate production processes. The objective of this dissertation is to propose a set of guidelines for using 4D BIM for managing production in housing retrofit projects. Such recommendations were devised to support decision makers involved in the management of this type of project, particularly regarding the identification and minimization of disruptions that affect final users during the construction stage. Design Science Research was the research approach adopted in this investigation, in which a set of prescriptios were proposed for the solution of real problems. In the present study, the solution is a set of guidelines to be adopted by managers. Considering the exploratory character of this research work, and some limitations in the empirical study, the understanding the problem was the more emphasized than the implementation of the solution. The empirical study was developed in a construction project carried out in Nothern Ireland, in which different scenarios for the construction phase were developed using 4D BIM models, in order to identify and reduce disruptions to the end users. The main contributions of this investigation were related to the characterization of different types of disruption, and the use of scenarios simulated in BIM models developed for analyzing alternative plans during the design and production stages.
35

Optimisation-based retrofit of heat-integrated distillation systems

Enriquez Gutierrez, Victor Manuel January 2016 (has links)
Distillation systems consist of one or more distillation columns, in which a mixture is separated into higher-value products, and a heat exchanger network (HEN) that recovers and reuses heat within the system. For example, crude oil distillation systems comprise crude oil distillation units (CDU), in which crude oil is distilled into products for downstream processing, a HEN and a furnace. Heat-integrated distillation systems present complex interactions between the distillation columns and HEN. These interactions, together with the many degrees of freedom and process constraints, make it challenging to retrofit or modify the operating conditions of existing distillation processes to accommodate changes in process operating conditions. Retrofit designs aim to re-use existing equipment when process objectives change, for example to increase throughput, improve product quality, or reduce energy consumption or environmental impact. To achieve these retrofit objectives, operational, structural and/or flowsheet modifications to the overall system (distillation columns and HEN) may be considered, subject to specifications and system constraints. This work proposes an optimisation-based approach to retrofit design for the capacity expansion of heat-integrated distillation systems, with a particular focus on crude oil distillation systems. Existing retrofit approaches found in the open research literature consider operational optimisation, replacing column internals, adding preflash or prefractionation units and HEN retrofit to increase the capacity of existing systems. Constraints considered usually relate to the distillation column hydraulic limits, product quality specifications and heat exchanger performance (e.g. minimum temperature approach and, pressure drop). However, no existing methodologies consider these possible modifications simultaneously; thus, beneficial interactions between flowsheet modifications, operational changes, heat integration and equipment modifications may be missed. In this work, retrofit design solutions for crude oil distillation are developed using a stochastic optimisation framework implemented in MATLAB to optimise the system operating parameters and to propose flowsheet, column and HEN modifications. Within the framework, the optimiser can propose addition of a preflash unit, modifications to the CDU internals and changes to its operating conditions; the separation system is then simulated using Aspen HYSYS (via the MATLAB interface) and the hydraulic performance of the column is analysed using published hydraulic correlations. The optimiser also proposes modifications to the HEN (i.e. installed heat transfer area, HEN structure and operating conditions), which is then simulated to evaluate heating and cooling utility demand. Either simulated annealing and global search optimisation algorithms are applied to identify the optimal design and operating conditions that meet the production requirements and product specifications. Industrially relevant case studies demonstrate the effectiveness and benefits of using the proposed retrofit approach. The case studies illustrate that combined structural and operational modifications can be effectively and systematically identified to debottleneck an existing crude oil distillation system with a relatively short payback time, while simultaneously reducing energy consumption per barrel of crude oil processed.
36

Creating a framework for the successful implementation of energy retrofit projects: a detailed case study of energy retrofits in Atlanta's Chastain Park

Pope, Bryan Christopher 10 April 2012 (has links)
This paper seeks to develop a framework for the successful implementation of energy retrofit projects in all settings, including those with the non-traditional structure and unique needs of some non-profit organizations. This will be accomplished using researched strategies for overcoming commonly associated challenges along with experiences gained through a real-life case study involving a multi-facility retrofit project in Atlanta's largest public park, Chastain Park. The framework includes the application of research based solutions for common challenges as well as specific strategies for the translation of collected data into an actual scope of work, methods for the collection of bids and selection of contractor(s), the importance of and methods for communicating amongst stakeholders, and the need for a dedicated project manager on site at all times.
37

Recomendações para o uso de BIM 4D na gestão de empreendimentos habitacionais de retrofit

Souza, Fernanda Justin Chaves de January 2015 (has links)
Os empreendimentos de retrofit vem ganhando destaque dentro do segmento de construção habitacional, dado o aumento de idade do estoque existente. A gestão de empreendimentos de retrofit apresenta muitos desafios, principalmente quando a execução da obra ocorre em edificações ocupadas. Em geral, há muitos desafios ligados às perturbações causadas aos usuários destas edificações. Alguns estudos realizados indicam que o Building Information Modeling (BIM) tem contribuído para a gestão da produção de empreendimentos novos. Entretanto, no âmbito de retrofit, o BIM tem sido pouco explorado, principalmente quanto ao uso de modelagem 4D no processo de produção. O objetivo desta dissertação consiste em propor recomendações para o uso de BIM 4D na gestão da produção de empreendimentos habitacionais de retrofit. Tais recomendações tem como propósito auxiliar tomadores de decisão envolvidos na gestão deste tipo de empreendimento, particularmente no que se refere à identificação e minimização de perturbações que afetam os usuários finais durante a obra. A estratégia de pesquisa adotada neste trabalho foi a Design Science Research, na qual se buscou o desenvolvimento de um conjunto de prescrições para um problema real. Considerando o caráter exploratório desta pesquisa e algumas limitações no estudo empírico, a fase de compreensão do problema teve maior destaque do que a fase de implementação da solução. O estudo empírico foi realizado em uma obra na Irlanda do Norte, sendo que diferentes cenários de execução foram propostos para a execução da obra, utilizando BIM 4D para a identificação e redução das perturbações para os usuários finais. Entre as principais contribuições do trabalho, pode-se destacar a caracterização das perturbações causadas durante as obras de retrofit quando ocupadas pelos usuários, assim como o uso de cenários simulados com o uso de BIM 4D, na análise de planos alternativos nas etapas de projeto e produção. / There has been a growing interest in retrofit projects in the house building sector, given the increasing age of the existing building stock. In general, retrofit projects bring a number of challenges, especially when works are carried out in occupied buildings. Much of these challenges are related to disruptions caused to occupiers. Previous studies have indicated that Building Information Modeling (BIM) has contributed substantially in production management for new projects. However, the application of BIM in retrofit has not been much explored, especially concerning the use of 4D modelling to simulate production processes. The objective of this dissertation is to propose a set of guidelines for using 4D BIM for managing production in housing retrofit projects. Such recommendations were devised to support decision makers involved in the management of this type of project, particularly regarding the identification and minimization of disruptions that affect final users during the construction stage. Design Science Research was the research approach adopted in this investigation, in which a set of prescriptios were proposed for the solution of real problems. In the present study, the solution is a set of guidelines to be adopted by managers. Considering the exploratory character of this research work, and some limitations in the empirical study, the understanding the problem was the more emphasized than the implementation of the solution. The empirical study was developed in a construction project carried out in Nothern Ireland, in which different scenarios for the construction phase were developed using 4D BIM models, in order to identify and reduce disruptions to the end users. The main contributions of this investigation were related to the characterization of different types of disruption, and the use of scenarios simulated in BIM models developed for analyzing alternative plans during the design and production stages.
38

Recomendações para o uso de BIM 4D na gestão de empreendimentos habitacionais de retrofit

Souza, Fernanda Justin Chaves de January 2015 (has links)
Os empreendimentos de retrofit vem ganhando destaque dentro do segmento de construção habitacional, dado o aumento de idade do estoque existente. A gestão de empreendimentos de retrofit apresenta muitos desafios, principalmente quando a execução da obra ocorre em edificações ocupadas. Em geral, há muitos desafios ligados às perturbações causadas aos usuários destas edificações. Alguns estudos realizados indicam que o Building Information Modeling (BIM) tem contribuído para a gestão da produção de empreendimentos novos. Entretanto, no âmbito de retrofit, o BIM tem sido pouco explorado, principalmente quanto ao uso de modelagem 4D no processo de produção. O objetivo desta dissertação consiste em propor recomendações para o uso de BIM 4D na gestão da produção de empreendimentos habitacionais de retrofit. Tais recomendações tem como propósito auxiliar tomadores de decisão envolvidos na gestão deste tipo de empreendimento, particularmente no que se refere à identificação e minimização de perturbações que afetam os usuários finais durante a obra. A estratégia de pesquisa adotada neste trabalho foi a Design Science Research, na qual se buscou o desenvolvimento de um conjunto de prescrições para um problema real. Considerando o caráter exploratório desta pesquisa e algumas limitações no estudo empírico, a fase de compreensão do problema teve maior destaque do que a fase de implementação da solução. O estudo empírico foi realizado em uma obra na Irlanda do Norte, sendo que diferentes cenários de execução foram propostos para a execução da obra, utilizando BIM 4D para a identificação e redução das perturbações para os usuários finais. Entre as principais contribuições do trabalho, pode-se destacar a caracterização das perturbações causadas durante as obras de retrofit quando ocupadas pelos usuários, assim como o uso de cenários simulados com o uso de BIM 4D, na análise de planos alternativos nas etapas de projeto e produção. / There has been a growing interest in retrofit projects in the house building sector, given the increasing age of the existing building stock. In general, retrofit projects bring a number of challenges, especially when works are carried out in occupied buildings. Much of these challenges are related to disruptions caused to occupiers. Previous studies have indicated that Building Information Modeling (BIM) has contributed substantially in production management for new projects. However, the application of BIM in retrofit has not been much explored, especially concerning the use of 4D modelling to simulate production processes. The objective of this dissertation is to propose a set of guidelines for using 4D BIM for managing production in housing retrofit projects. Such recommendations were devised to support decision makers involved in the management of this type of project, particularly regarding the identification and minimization of disruptions that affect final users during the construction stage. Design Science Research was the research approach adopted in this investigation, in which a set of prescriptios were proposed for the solution of real problems. In the present study, the solution is a set of guidelines to be adopted by managers. Considering the exploratory character of this research work, and some limitations in the empirical study, the understanding the problem was the more emphasized than the implementation of the solution. The empirical study was developed in a construction project carried out in Nothern Ireland, in which different scenarios for the construction phase were developed using 4D BIM models, in order to identify and reduce disruptions to the end users. The main contributions of this investigation were related to the characterization of different types of disruption, and the use of scenarios simulated in BIM models developed for analyzing alternative plans during the design and production stages.
39

O RETROFIT SUSTENTÁVEL COMO UMA ESTRATÉGIA PARA A REABILITAÇÃO CONSCIENTE DO PATRIMÔNIO CULTURAL ARQUITETÔNICO / THE SUSTAINABLE RETROFIT AS A STRATEGY TO REHABILITATE CONSCIOUS ARCHITECTURAL CULTURAL HERITAGE

Gaspary, Fernanda Peron 27 February 2012 (has links)
This dissertation constitute a reflection on the sustainable Retrofit as a conscious strategy to rehabilitate the architectural cultural heritage. In this context, the concept of Retrofit is explored and associated with various dimensions of sustainable development. This research also reviewed aspects relating to diversities and similarities between models of interventions. The methodology accommodated bibliographic search, consultation on regulatory agencies of brazilian constructions, theoretical-historical survey and direct observation on case study of a building of historic heritage, the Museu do Pão, located at the top of the Vale do Taquari, RS. In this case study, the Retrofit was analyzed from Brazilian Association of Technical Standards to a broader perspective on research. The results seems to evidence that are other sustainable development variables were detected after the Retrofit in addition to the environmental dimension. These dimensions are the cultural, social, and economic. These results may help explain the emphasis term's sustainable Retrofit on architectural cultural heritage. / Esta dissertação constitui-se em uma reflexão a respeito do Retrofit sustentável como uma estratégia consciente para reabilitar o patrimônio cultural arquitetônico. Neste sentido, o conceito de Retrofit é explorado e associado com as várias dimensões do desenvolvimento sustentável. Esta pequisa também revisou aspectos relacionados às diversidades e às adjacências entre modelos de intervenções. A metodologia adotou pesquisa bibliográfica, consulta em normativas, levantamento teórico-histórico e observação dirigida no estudo de caso de uma edificação do patrimônio histórico, o Museu do Pão, localizado no Alto do Vale do Taquari, RS. Nesse estudo, o Retrofit foi analisado a partir de uma perspectiva mais abrangente do que a proposta pela Associação Brasileira de Normas Técnicas. Os resultados parecem evidenciar que outras variáveis do desenvolvimento sustentável foram detectadas após o Retrofit além da dimensão ambiental. Essas dimensões são a cultural, a social e a econômica. Esses resultados podem ajudar a explicar a ênfase no termo Retrofit sustentável em patrimônios culturais arquitetônicos.
40

Retrofitting heritage buildings for energy and seismic upgrades

Kobraei, Mohsen 25 September 2020 (has links)
The application of retrofit options to existing heritage buildings has become one of the most interesting topics in construction. In Victoria, BC, Canada, only 4% of commercial or institutional heritage buildings have been upgraded to current building codes in the last 10 years. Remaining 96% buildings exist with poor energy performance characteristics and a risk to occupant safety in the event of a damaging earthquake. This study investigates the importance and benefits of simultaneous energy and seismic retrofitting of existing heritage buildings. It presents a case study for a building with identifiable heritage value, located in Victoria, BC, Canada, and analyzes five feasible options in terms of energy retrofitting and presents a solution for both seismic and energy upgrading. To this aim, the energy retrofit options are compared based on the amount of saved energy, annual heating demand and estimated costs. The seismic solution is designed based on the weakness and needs of the building, and cost-effectiveness. Finally, the best solution is selected for a building that dates back to the beginning of the 20th century. This study shows that the integration of energy and seismic retrofitting of heritage buildings provides economic benefits to owners while improving energy savings and building safety. / Graduate / 2021-08-31

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