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This thesis focuses on small scale residential cooling application with unitary air conditioning units as they are wide spread in the so called Middle East North African Region. The presence of these single room or single apartment cooling systems is evaluated and their impact throughout the region assessed. They have a tremendous impact on the electric supply in countries like Saudi Arabia where most of the households already have an AC-unit. The impact in other countries with relatively less installed systems, like in Egypt, is already crucial and leads to regular power cuts. However, the stability of the grids of these countries will decrease further with a higher penetration rate of electric air conditioning systems. Current technology development aims to reduce the buildings cooling energy demand, increase the coefficient of performance, or to substitute the cooling mechanism with a different approach such as sorptive cooling systems. However, these systems require a costly and time intensive change of the building structure or an exchange of the existing cooling system. Due to this reasons, this thesis focuses on the additional installation of a small scale PV electric system, including a battery and applying advanced control strategies to utilize the thermal storage capacity of the building masses. Therefore, the present room cooling system is modeled as a reference system as it could be present throughout the entire region. This system consists of a room model of a typical apartment structure and is cross validated. Two use cases are applied: a bed room and a living room. Further, it includes a model of the solar electric system which is as well parametrized to regional values. Newly, a split unit model and an extended Kinetic Battery model are set up. The single models are combined to an entire system simulation. Afterwards, the main parameters are varied in particle swarm optimization runs to determine the impact of various boundary conditions, such as the electricity price and feed in tariffs, battery and thermal storage capacities, and solar collector field size. The simulation results are compared in terms of levelized costs of cooling, solar coverage rate and the solar cooling autonomy. The findings are compared in a case study. This study highlights the results of the Hurghada, Egypt city district of El Gouna. There, personal observations of the results where possible and an in depth analysis of the results was undertaken. In this location, the levelized costs of electricity for a small scale PV system with 1kWpeak drop there to 0.18USD/kWh with a short investment period of 5 years. They even drop to 0.08 and 0.05USD/kWh when taking an investment period of 15 or 25 years into consideration. With this values, various levelized costs of cooling are simulated as a parameter field of the particle swarm optimization. The findings show, that in most cases, the cooling costs become negative, even with relatively short investment periods. Within a bed room, a solar coverage rate of 0.9 can be achieved with a small scale PV system with weighted costs of only 677USD. In terms of solar cooling autonomy, the most cost efficient system has weighted costs of1,036USD, resulting in a coverage rate of 0.71. The living room air conditioning system can achieve best weighted costs of1,459USDfor a cooling autonomy of 0.86.Further, the practical application of a small scale PV electric solar cooling system was evaluated by the author in the case study location itself. The limitations of the theoretic system design are presented and discussed. Part of this analysis is the thermal stratification in typical vaulted apartment structures as they have a huge impact on the deviation between simulated and measured room air cooling demand.
Within the application context of interior spaces, this thesis investigates the emerging area of body-driven energy harvesting technologies from the perspective of human computer interaction (HCI) design. Upcoming innovations in new materials and low-power devices have enabled the conversion of body movements such as steps and arm movements into electrical energy for powering small computational things. Everyday interior spaces such as public buildings or homes can be fitted with new materials that harness human kinetic energy to produce electrical energy. Recent developments in the area of engineering and materials science aim to make these technologies more efficient. However, research about the implications of implementing them in the everyday from the perspective of the experiences and interactions of the people adopting these technologies is highly under-explored. In order to examine this design space, this research proposes to identify emerging concerns and challenges brought by everyday engagement with electricity production that need to be addressed through an interaction design inquiry.
To investigate the above proposition, a design program situated between the field of human computer interaction research and the practice of e-textile design is formulated with the aim to
investigate, at the scale of the interior, how static electricity can bring new perspectives and possibilities for ways of engaging with e-textiles, and designing interactions for energy harvesting with textiles.
The research sets up four research studies to systematically explore the design program. These research studies focus on four questions of how static electricity shapes e-textiles, how electrostatic textiles shape e-textile interactions, how e-static interactions shape everyday behaviours and how e-static studies shape energy interpretations. By developing a working knowledge of textile-based triboelectric generators, various body-generated electricity systems of different scales are envisioned. In the process of making, discovering and exploring different textile systems, questions regarding human interactions, material behaviours and the role of electricity in the everyday are discussed.
This thesis contributes to the practice of e-textiles by creating the foundational knowledge of using static electricity as a resource in e-textile design and development without needing specialised materials. Furthermore, it contributes to the field of human computer interaction research by further developing the topic of energy harvesting as a research area of interaction design. The thesis identifies two key areas for addressing challenges presented by body-driven energy harvesting with HCI which include considering accumulation of interactions over time and incorporating the electric properties of the body in interaction.
Additionally, practical outcomes of this research include:
1) www.estatictextiles.cc- An online handbook for learning about and working with static electricity and e-textiles which includes tutorials and examples from the research process.
And 2) E-static textiles prototyping board- A prototyping board developed for easy integration of static electricity and textiles to be used as an educational tool for designing and prototyping electrostatic energy-related interactions.
Nowadays, society is becoming increasingly conscious of the adverse effect of energy use on the environment, contributing to the depletion of fossil fuels and increasing global warming. Because of the substantial contribution of building energy to these concerns, the intention should be not only to improve building energy efficiency but also to promote the use of renewable technologies, especially solar energy. Today building-integrated photovoltaic (BIPV) and building-integrated solar thermal (BIST) technologies are recognized by building designers as innovative technology for clean energy and greenhouse gas reduction, especially in cities, where multi-story buildings are dominant with limited roof area.
For the Mediterranean area, the high level of solar radiation and plentiful sunny hours make it appropriate for solar system installation, however, the development of solar energy is still limited. Moreover, due to the high population growth rate, lack of local resources, high energy price, and urbanization, one of the priorities in the Mediterranean area is to promote the energy efficiency of the building both on the supply side and demand side.
Therefore, this research aims to investigate the potential of installation of the photovoltaic (PV) and solar thermal (ST) technologies in the new multi-family residential building envelope in the Mediterranean area, taking Amman, Jordan, as a case study. The focus of this research is on the typical multi-family residential buildings in Amman, as it is the city where about 50% of the new construction in Jordan is taking place, and the residential buildings are the major consumers of energy and electricity in Jordan. The multi-family buildings also form about 75% of the total housing stock in Jordan. The typical multi-family building studied here is composed of five main floors, contains ten residential apartments; the area of each apartment is 150 m2. It is assumed that the building is located in a common residential urbanized zone in Jordan, with 6 m sides offset and 8 m back offset, assuming that one side is facing the main street, and all the buildings have a maximum allowable height of 15 m. All the architectural parameters related to the multi-family buildings have been defined through analyzing the residential building stock in Jordan.
In order to achieve the research aim, the possibility of reducing the energy demand of the typical multi-family building in Amman, Jordan, through passive and architectural design strategies was firstly investigated. After that, different performance criteria were evaluated, mainly quantitative criteria including energy consumption, energy production, and life cycle assessment (energy, carbon, cost). In addition to the qualitative criteria, including visibility and functionality, the purpose here is to emphasize the substantial function of BIPV systems. Each performance criterion was assessed alone. Then, all the performance criteria results were presented in a decision support matrix, which can be used as a comparison to evaluate and identify the solar system's application of choice, based on the criteria of the user. Moreover, a new energy index was formulated to evaluate the overall annual energy performance of BIPV design in terms of multifunctional effects on building energy.
Different methods were adopted in this research; the qualitative criteria were evaluated based on the literature review analysis, while the quantitative criteria were evaluated by using different simulation software, previous literature review, and spreadsheet calculations.
Literature review analyses were conducted in order to identify the relevant possibilities and the aesthetical solution the market offers, and the multiple benefits for PV and ST integration. The knowledge acquired from this part played a significant role in choosing and designing the proposals of PV and ST installation into the multi-story building envelope. Regarding the simulation studies, different building and energy simulation software was used to simulate and optimize the energy performance of the typical multi-family building in Amman, Jordan, through passive and architectural design strategies, as well as to find out the optimum design of the energy system in terms of energy performance (energy demand of the system, and solar energy fraction), and to investigate the energy-saving potential of PV and ST systems with various designs (tilt angles, azimuth, installed area, etc.). For the building energy simulation, each zone in the building was modeled as a space of its own. The energy demand was calculated on an hourly basis for a period of a whole year. The results from the simulation analysis, related literature and guidelines were adopted to conduct a life cycle assessment through spreadsheet calculation, to determine the long-term performance in terms of energy and carbon emissions, as well as cost considerations, taking into account the current market practice. The cradle-to-grave approach was adapted for the environmental life cycle assessments.
The general conclusion of this research is that installing the PV modules into the multi-family buildings envelope in Amman, Jordan, makes a positive contribution in terms of energy performance, as PV systems can cover up to 97% of the new building electricity demand when they are installed on both the roof and south façade, and up to 43% is covered by installing the PV modules into the south facade. Regarding the environmental life cycle assessment, the results proved the carbon saving potential of all the proposed PV systems, as the energy payback time (EPBT) is between 1.5- 3.5 years and the carbon payback time (CPBT) is between 3.4- 7.8 years. However, for the life cycle cost assessment the result showed that due to high capital cost and low cost of electricity, neither system is currently feasible for investment, as the payback time (PBT) is between 9.0- 16 years. However, with future advances in each system and more efficient designs, the payback periods would become tangible and therefore yield better performances. Lastly, the results were used to derive a decision support matrix aimed at providing a friendly approach to facilitate the implementation of solar building applications.
When going deep into the area of sustainability and looking at the crosslinks that open up regarding the practice of design, a dark narrative appears whereby sustainable design is a failing practice, either aiming too high by trying to tackle global, inter- and intragenerational challenges, or aiming too low by focusing on, for example, material impacts of new products and services; this narrative appears to have an upper hand over one that is more positive and constructive that sees the strengths and potentials that design can bring to the challenges of sustainability. While the growth-oriented sustainable development discourse still dominates the way sustainable design is practiced, there are other streams with a more holistic view of sustainability. These streams are rooted in a post-growth / no-growth or strong sustainability discourse, which are slowly making their way into design practice through the guise of sufficiency, resilience and activism with a common theme of sharing knowledge, allowing citizens to be an active part of their community.
The dark narrative of sustainability in design as well as the call for designers to transform a practice of “un-sustainability” into one that allows “futuring”, leaves most of them shrugging their shoulders in light of how to implement the theoretical (utopian) requirements into their own practice. I argue for providing a different, more positive narrative, moving past the finger-pointing attitude towards reminding oneself what the practice of design in the context of sustainability can bring to the table.
Why there are new directions in sustainable design is largely because design has broadened beyond its product and service fixation towards a more process-oriented practice and an awareness of the impact designers have on this world. In these processes, designers are often taken outside the boundaries of growth-oriented economic progress towards social progress. They are continuously reminded that they cannot operate outside of a societal context and that their work has an impact on the Earth’s dynamic equilibrium (however small it might be).
Thus, the aim of my work is to re-frame sustainable design as a default configuration, stripping it from the unwieldy term of sustainability and extracting its core features of transformation, participation and future-focused thinking. Considering this core configuration, design is bound to be situated between anthropo- and eco-centricity, putting into question current user- and human-centric design approaches that tend to marginalize the everyday context and wider implications of the designed product or service.
Through an investigation that spanned the last five years, I have come to realize that sustainable design has nothing to do with a specific practice, but rather with a mindset which is, at its basis, tied to ethical considerations rooted in everyday life. It is moreover tied to broad, interdisciplinary knowledge that is needed to grasp the interconnected and global challenges that lie ahead. To make this point, in my work I am retracing the steps from the early roots of sustainable design within the sustainability movement towards its radical opening in different directions such as design activism, transformation design, design for social innovation and participatory design.
Furthermore, I propose a re-framing of the practice of sustainable design, (tentatively) linking it with a research-through-design approach and subsequently, through the design case, constructing a dynamic, interdisciplinary action repertoire for designers.
When framing this renewed idea of sustainable design, not only do the two dimensions of transformation and participation almost automatically appear in the current discourse, but also the notion of opening up contexts through design in a way that is directed towards possible (sustainable) futures becomes apparent. Several overarching perspectives resurface in the course of this work:
1 Opening – How can designers open access to contexts, tools, knowledge and technology through collaborative, interdisciplinary action?
2 Making – How can designers provide processes to involve stakeholders in critically assessing and making possible futures?
3 Transforming – How can designers transform contexts and situations from one state to a preferred one (and how can they facilitate the negotiation-processes tied to them with regards to social equity and intra-generational justice)?
The topic of transformation and future-focused thinking is currently engaging most of design, not exclusively sustainable design, and this thinking seems to provide an underlying idea that design may be able to provide at least part of the skill-set required to cater to this transformation. It is, however, not only the context and situations design claims to transform, but also user behavior and market incentives. In this research, transformation is viewed as a careful byline to a project which spans almost six years and is now coming to a close.
The design case for this research is the project Neighborhood Labs which has been run by an interdisciplinary group of design researchers, citizens and other stakeholders in a central, but isolated area in Berlin’s Mitte district. It incorporated the development of a research concept and experimentation process which builds on a participatory design methodology as well as a living lab approach. It was planned open-ended with the potential of stakeholders taking over after the official end of the research project.
In terms of sustainability, the subject and guiding theme of sharing and collaboration was the baseline of the design phases and iterations. While focusing at first on the sharing of concrete objects in a specific community of practice, there was a shift to sharing knowledge, as well as to the empowerment of citizens to impact local decision-making processes, a much fuzzier subject than the sharing of objects or services. The project was run in three intertwined phases:
– Sharing phase / Neighborhood lab: Setting up and running a living lab. Investigating the context and building the infrastructure. Approaching the neighborhood and designing tools for gathering insights about needs and issues within it while drawing active citizens towards the project. After this step, insights inform the research process and help focus the research question further. This phase produced several concepts and sketch prototypes in collaboration with the stakeholders of the Fischerinsel, Berlin.
– Infrastructure phase / Designing infrastructures & fostering change: Designing and testing participatory tools such as the Hybrid Letterbox, an analog-digital bridge device, in order to discuss and evaluate questions of social cohesion and communication within the neighborhood and to activate citizens for involvement in these issues.
– Transfer phase / Design transfer: opening up the context and pushing the methods and tools outside of its initial project and creating new instances thereof.
As I am reflecting on the process of a long-term project now behind me, such as working through trial-and-error phases, prototypical research-through-design attempts and the immersion in the Fischerinsel-context that the research group grew a part of, several key directions in the dealing with and conveying of sustainability challenges appear.
On a practical level, these directions materialize in the categories of investigative action, participatory tools and workshop formats, which are distilled from a broad range of interdisciplinary actions conducted over the course of the research, leading to an action repertoire for transformation which I propose as one of the outcomes of my work.
On a theoretical level, I argue for sustainable design by default, meaning sustainability as an inherent, embedded goal of any design process, integrating a research-through-design mindset in sustainable design or vice versa. In further steps, this entails restructuring the way we teach design and how design practice is informed throughout its process.
Elastic gridshells are celebrated for their striking biomimetic curves, long spans and efficient material usage. Constructed from a grid mechanism of slender beams, an elastic gridshell is assembled on a flat surface then repositioned into its final curved shape after which stabilising elements are added and the structure becomes a stiff load-bearing shell.
While elastic gridshells are efficient in their built-state, the established methods with which to erect them (‘lift up’, ‘push up’ and ‘ease down’) are associated with substantial complexity, cost and time which inhibit their adoption. The central research question of this thesis asks whether elastic gridshells can be erected by means of pneumatic falsework (i.e. ‘inflate’), if so how and what would be the implications of doing so.
The work presented in this thesis proves that the pneumatic erection of elastic gridshells is not only feasible but can offer many advantages (such as speed of erection, structural robustness and architectural qualities) over existing shelters for humanitarian, event and architectural applications. A literature review is presented on the historical precedent for this novel method. The computational challenges of simulating the complex erection process are investigated in depth leading to the development of bespoke simulation methods based on the novel application of a projection-based dynamic relaxation solver.
Case studies and a benchmark compare state-of-the-art finite element solvers based on both global and local stiffness revealing their quantitative and qualitative differences giving some indication as to the future of finite element modelling for the built environment in engineering, research and education. Innovative prototypes of augmented and virtual reality engineering tools for education are presented as wider reaching applications of the novel simulation method developed for this thesis.
The simulation methods developed to answer the central research question deliver valuable findings relating to the scope of feasibility and the practical execution of the novel method including: suitable shapes and sizes of shells, ‘trigger’ pressures required, the function and importance of tethering cables during erection, development and detailed analysis of erection sequences and identification of material suitability and performance criteria. One small and two full-scale physical prototypes were built which validate the novel computational methods to a high level of precision, offer practical detailing solutions and demonstrate the architectural and humanitarian potential within the pneumatic erection of elastic gridshells.
This dissertation offers a critical engagement with design’s implication in the ontological constitution of gendered, racialized, subjugated bodies. To do so, it starts from a broad understanding of design as an activity that articulates modes of being in the world — and that, in so doing, also shapes itself. This approach is grounded on an interrogation of the political motives that permeate and inform design processes; I take particular interest in how these have been manifested throughout the history of birth control technology.
Starting from this background, I outline and propose the concept of technoecologies of birth control — that is, spaces that emerge through the performances of co-constitutive material-semiotic actors, for the purposes of birth control. Throughout this dissertation, I identify two fundamental sets of actors operating within the technoecological space: bodies and things. The co-constitution of these actors is realized across historically, geopolitically, socioculturally, technoscientifically located performances; as such, technoecological actors are approached as relational, contextual and mutually structuring entities.
This conceptualization of technoecologies of birth control is informed by feminist and decolonial theories, and posits that these spaces are crucial for the establishment and sedimentation of biopolitical regimes of domination. Design is thoroughly implicated in the emergence of technoecologies of birth control, as it holds a crucial role in the management and regulation of bodies characteristic of biopolitical regimes of domination. In other words, design inscribes ontological meaning onto some bodies in detriment of others; it is with the sedimentation of these conditions that bodies become coded as ‘naturally’ or ‘fundamentally’ different. The constitution of difference amongst material-semiotic actors in technoecologies of birth control is thus articulated by design; in other words, it is the result of a planned, deliberate inscription of ontological meaning.
My interrogation of design’s role in the constitution of subjugated bodies occurs within the scope of these technoecologies. Starting from this framework, I discuss the insights offered by a series of experiments (‘Yarn Sessions’ and 'Oniria') conceived as both explorations of the technoecological space, and speculations on the instability of the social constitution of bodies by design. My theorization of technoecologies of birth control happens, thus, through a process of research through design — that is, a process in which theory and practice are deployed as mutually informing forces in design research. Through the analysis of these design experiments, I propose three fundamental aspects of the performances of material-semiotic actors within technoecologies of birth control: relativity, opacity, and duplicity.
Decolonizing the Earview of Design: Listening Anxieties and the Apparatus of Auditory Governance
(2018)
This dissertation attends to the intersection of sound, material culture, racism, and police violence in Brazil from a decolonizing perspective. With a focus on theories informed by cultural and sound studies, it unravels the contingent arrangements through which certain designed objects and practices function as material-discursive nodes for the normalization and perpetuation of racialized violences. To explore these ideas, it reads design—a field of knowledge and a set of practices—as a material-discursive apparatus, accountable for not only the results but also the conditions of possibility for any research endeavor.
The main driving force of this work is the identification and evincing of ‘listening anxieties.’ These emerge through enactments of political consensus, policing, and compliance; the articulation of these three in institutional, designerly, as well as everyday practices is what this research identifies as the Apparatus of Auditory Governance (or AAG). More specifically, I look at three manifestations of these auditory governances in contemporary Brazil—from the early 2000s to the judiciary Coup d’Etat of late 2016. These range from the criminalization of jukeboxes by a Military Police acting outside the scope of written law in so-called ‘pacified’ neighborhoods in Rio de Janeiro, to the construction of a seven kilometer-long acoustic barrier in the city as a device for urban segregation, to the deployment of sound bombs as devices for the enforcement of silence by the same police force in São Paulo.
The articulation of auditory governances, however, is not fixed; rather, it shifts and mutates to account for distinct and diverse experiences of listening. These shifts are what this work calls earviews: a conceptual orientation which determines the “listening point” where narratives and perceptions of auditory reality unfold from. The AAG, articulated and deconstructed at the intersection of distinct and conflicting earviews, forms the main method of this dissertation, and is of particular interest for sound and design studies. By understanding the earview as an asset of and for designing, it is possible to interrogate the role of design in the enforcement, reproduction, and normalization of sonic violences, and the erasure of other(ed) narratives of listening. Rather than simply evincing the hegemony of normative—qua racialized—earviews, I intervene by reading them through first-person accounts and storytelling stemming from fieldwork with artists and activists in Brazil, as well as from two movies by Brazilian directors—O Som ao Redor (2012) and Branco Sai, Preto Fica (2014). These intersections are further complemented by a semi-fictional narrative created throughout five collective pedagogical sessions fusing designing and fabulation. This format, named “Yarn Sessions,” is my methodological proposition for design research in this work.
This research started out by posing three broad questions relating to the connection between auditory practices—i.e. sounds and their social, cultural, and political engagements—and the design of listening devices. It asked: what is the contribution of design to the politics of mediated listening and its devices? What might be the possible, probable and/or preferable enactments of the political agency of designed listening devices? These initial questions are all addressed by this work, and have shifted from their initial form as a general investigation on the entanglement of design and listening, to offer an inquiry and an intervention on violences enacted with and through sound.
This work thus participates in a re-historicization of the colonial underpinnings of design, while at the same time offering a decolonizing methodological proposition for design research and design studies with a sound and listening-oriented locus. It demonstrates that the material conditions of sonic violence—from architectural planning to transitional/illegalized sound objects to the development of weaponry—are a form of ontological design (cf. Anne-Marie Willis) which succeeds by making its own colonial and racialized ethos discursively and materially invisible. This ontological enunciation demands the accountability of the designer as both producer and reproducer of racialized/colonial phenomena in the making of their own practices.
Yet this research does not align itself completely with discourses from the “ontological turn” or “new materialisms” in philosophy (cf. Karen Barad), insofar as these often undermine and erase the role played by coloniality and “racialized assemblages” (cf. Alexander Weheliye) to the constitution of its own ontologies and epistemologies. My proposition for design understands the field to constitute in itself an ontoepistemology (cf. Willis, Gloria Anzaldúa), albeit reading such ontological alignments through decolonial and critical race studies. In so doing, it opens up a new field of inquiry in which sound studies and decolonial thought inform designerly inquiries into material culture not only for the evincing of specific material-discursive phenomena (e.g. sonic violences), but also for intervening on them with intersectional and decolonizing frameworks.
Introduction
Following their first meeting in Düsseldorf in 1961, Joseph Beuys and Nam June Paik began their lifelong series of artistic collaborations so-called EURASIA. Sharing a common interest in Europe and Asia, they started to consider Europe (=West) and Asia (=East) as one continental culture, and tried to connect them as EURASIA.
Containing Europe and Asia, Eurasia is one continuous mass of land. Europe and Asia, or West and East are merely imaginary divisions, but once they are named Europe and Asia or West and East, this fixed division makes it difficult to understand that these two areas are in fact one continent with common roots, and that they developed through mutual influence. To realize the continuity of Europe and Asia and understand how to connect these two regions is becoming an urgent question.
In our globalized world, it is becoming impossible to uphold protection through the entity of the nation-state, which defines the enemy as being outside the nation. In order to find an alternative to the nation-state, we need to look back in history and restructure the world on a more abstract level; in other words, the sublation of Westphalian sovereignty which developed after the Thirty Years’ War is now required.
Also if Asia becomes one political entity, just as Europe is becoming one political entity, the tension between Europe and Asia will be intense; it will be no different from that between nations, which caused two World Wars. As Asia, a large part of which was once colonized by Europe, begins to gain political and economical power, it becomes necessary to prepare a plan to reconcile Europe and Asia. Meanwhile, if Eurasia is united as an expansion of the nation-state, the result may be regional hegemony with a one-sided national perspective, similar to that of the Greater East Asia Co-Prosperity Sphere led by the Empire of Japan. The Eurasian Economic Union led by Vladimir Putin’s Russian Federation threatens to make the same mistake. Bearing in mind the fact that the bloc economy triggered World War II, to connect Europe and Asia while eschewing regional hegemony will be crucial for our co-existence in the 21st century.
Having endured World War II, both Joseph Beuys and Nam June Paik were aware of the contradictions of modernity and the nation-state which originated in Europe. They reflected on how to overcome divisions such as those between nations, between Europe and Asia in colonial history, and between East and West during the Cold War at that time. Eliminating borders, Beuys and Paik’s utopian vision of EURASIA is an abstract and archetypical metaphor for connecting Europe and Asia, West and East, or two opposite things into one, and it will give us a hint on how to overcome the divisions caused by modernity.
This thesis investigates and describes the design and structural behaviour of elastic gridshells. Elastic gridshells are shell structures composed of a single- or multi-layer grid of continuous profiles, which are initially straight and will be progressively bent until achieving an architecturally and structurally satisfactory geometry. Usually used as medium to large span surface structures, elastic gridshells present a wide variety in their surface geometry, grid configuration and materiality. One important structural criterion of elastic gridshells is the high residual stress to which they are subjected after the bending process. Using materials with high limit strain, the residual utilisation rate can be reduced. In the first part of the work, the structural aspects to be considered on the design procedure of elastic gridshells are described and identified on existing design approaches. Then, the mechanical properties of available materials, suitable for elastic gridshells, have been compared and application examples have been presented and illustrated.
Elastic gridshells offer significant cost and time advantages during the production, transport and construction processes. Nevertheless, the shaping of the initially flat grid also generates important bending stresses on the structures, reducing therewith their bearing capacity against external loads. In order to diminish the initial stresses, profiles with low sections and materials with low modulus of elasticity are usually chosen. However, this leads to a reduction of the global stiffness of the gridshell which can result in stability problems. With an optimisation of the grid pattern - orientation and arrangement of the grid profiles - a minimisation of the profiles’ curvature can be obtained and the load-bearing capacity of the gridshells improved. In the second part of the thesis, an optimisation method based on variational principles for regular and irregular gridshells is proposed and different case studies presented. The aim of using variational principles is to establish extremal functions which minimize the value of quantities related to particular grid properties. These properties are: the curvature of the profiles, the distance to a target surface geometry and the deviation of the edge lengths from a desired mesh size. The advantage of this method is that weighting factors can be applied to the grid parameters to be minimised, so that a variety of grid configurations can be established responding to different specific requirements.
The bending process and load-bearing behaviour of elastic gridshells can be analysed using three-dimensional finite element models. During the shaping of the profiles, internal forces are induced on the structure, so that the final equilibrium shape of the gridshell will be attained once its edges have been fixed, the bracing elements have been assembled and the external shaping forces have been removed. The goal of the numerical analysis is to quantitatively evaluate the geometry and material stresses resulting from the shaping process and the load-bearing capacity of the gridshell under external loading. In the third part of the thesis, the influence of the orientation and arrangement of the grid profiles on the residual stresses after erection process and on the distribution of forces and deformability of the gridshell under external loading are analysed on three regular anticlastic gridshells with varying grid pattern. Moreover, the potential and limitations of using tensile membranes as restraining and at the same time covering element of elastic gridshells are studied on a hemispheric regular elastic gridshell.
Numerical techniques are commonly used for the calculation of stress distributions and displacements of complex indeterminate bearing structures. Nevertheless, to model the elements they are composed of and the connection properties between them, simplifications and approximations are done. The purpose of the fourth and last part of the work is to analyse the influence of these simplifications on the results of the simulation and thereby recalibrate and benchmark the numerical models with physical prototypes. Two gridshells composed of GFRP profiles have been built: an irregular hemisphere of 10 m diameter, braced with a third layer of profiles, and a regular hemisphere of 5 m diameter, restraint with a tensile membrane. The prototypes have been loaded symmetrically and asymmetrically applying point loads at the grid nodes and the resulting nodal displacements have been compared to those calculated with the numerical models.
My doctoral thesis with the title „Rebuilt Rubble - Community Gardens in the South Bronx from 1970s to the 21st century: Common land use in the inner city from a socio-economic open space planning perspective” is focused on the assumption that people are longing for and are committed to a common urban open space land use form in the inner city – a hypothesis that I investigated by analyzing the development of community gardens in the study area South Bronx from the 1970s to the 21st century.
My thesis is contextualized in the research fields of social open space planning and urban design. The analysis is based on qualitative data collection that encompasses census data, plans, open interviews and participatory observation and includes the discussion of secondary literature regarding community gardens and urban open space development in the South Bronx.
Since the urbanization and industrialization at the end of the nineteenth century residential space in densely build-up inner cities, and especially in low-income neighborhoods, has been reduced often to a minimum, and privately usable open space is absent in many cases. Starting with the global economic recession of the 1970s in the urban centers of North American cities such as New York City there have been privately, but collectively used gardens created on public open land. These so called community gardens were started by low-income residents on vacant property lots in the vicinity of their apartments in order to improve their quality of life and in answer to the “neglect” of their neighborhoods by the government and municipality. Today there are about 600 community gardens in the metropolitan area of New York City and 44 gardens alone in the area called South Bronx, the study area of my thesis.
I analyze in my thesis the development of this common land use in the study area South Bronx from a social-economic and open planning perspective. The case study of my research is focused on community gardening and the “casita”, the small hut that low-income residents with Latin American and Caribbean cultural background build themselves out of found and recycled materials in many community gardens in the South Bronx.
My thesis researches the development of community gardens in the South Bronx since the 1970s influenced by often conflicting interests of various land use groups, residents and city planning agendas until today. It is a document of the humans’ need for common urban open space land use and of their commitment to the community garden land use form in the inner city.