Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 17 - 20 August 2015, Amsterdam, The Netherlands The physical model in structural studies within architecture education: paradigms of an analytic rationale? Maria VRONTISSI* *Doctoral Candidate ETH-Zürich Stefano-Franscini-Platz 5, Zurich 8093, Switzerland vrontissi@arch.ethz.ch Abstract In a quest for a means to develop conceptual structural awareness within a creative design scope, this article discusses the presence and use of the physical model in various teaching and learning practices related to structural studies (analysis or synthesis studies) within architecture education. The work is based on the hypothesis that structural engineering is a design discipline and modelling is one of the distinctive methods of inquiry appropriate to the culture of design. Following this line of thought, the role of the physical model – as an instance of modelling – in structural studies is discussed as a reflection on the way of reasoning in structural design. Keywords: structural design, structural engineering, structural studies, architecture education, physical model, modelling, synthesis studies, conceptual studies 1. Introduction – Scope of work In a quest for a means to develop conceptual structural awareness within a creative design scope, this article discusses the presence and use of the physical model in various teaching and learning practices related to structural studies (analysis or synthesis studies) within architecture education. A wide, yet not exhaustive, range of representative educational practices is discussed in order to formulate a case about the value and potential of the physical model as a conceptual design tool in structural studies. However, the purpose of the article is not merely to address questions related to educational research regarding the appropriate learning theory or didactic strategy for such studies; neither to simply discuss the role and potential of the physical model per se or as a design tool, as it would have been the case in a framework of visual or design studies research. The study serves as a means to tackle a rather epistemological question: to comment on the mode of reasoning in structural studies – be it in education, practice or research – and build an argument about the very nature of structural design itself. Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 2. Research Motivation – Research Hypothesis – Research Question In architecture education, structural issues are typically approached within an analytic rather than a synthetic scope, often resulting to a limited comprehension of global structural performance. Though these deficiencies are often attributed to the intrinsics of the particular educational framework (Foug [14]), the discussion about the lack of conceptual structural awareness remains likewise pertinent in educational reports (May & Johnson [23]), academic and professional discourse (IASS [19]) or statements of leading practitioners (Schlaich [28]) about structural engineering education and practice: inadequate structural insight from the architect, limited conceptual design input from the structural engineer. In the prevailing paradigm, based on the dipole ‘science-art’, structural studies operate within the scientific realm; structural engineering (employing ‘problem-focused’ strategies to deal with ‘welldefined’ problems) following the scientific paradigm as opposed to architecture (coping with ‘illdefined’ problems in a ‘solution-focused’ approach) within the artistic sphere (Lawson [21]). The present work adopts the proposition that engineering is a design discipline as first suggested by Simon [29] and follows the argumentation about the three cultures of human knowledge, as introduced by Archer [2] and then elaborated by Cross [10]. We therefore work with the threefold ‘science-art-design’ instead, structural design being placed under the design umbrella, just as its architectural counterpart. (Figure 1) In this framework, structural design is discussed as apt to embrace ‘designerly ways’ (Cross [10]) that is to acknowledge the open-end nature of structural design issues and the problem-solving mode of the structural designer (‘satisficing’ vs. optimizing) employing a synthetic design-erly rather than an analytic scientific rationale and relevant modes of reasoning. Following this line of thought, structural design is to share methods of inquiry appropriate to the culture of design – namely synthesis, modelling and pattern-formation – and distinct from those employed by the cultures of science or the arts – their modes of inquiry being the controlled experiment, classification and analysis and the analogy, metaphor, criticism and evaluation respectively. Figure 1: The three cultures of human knowledge and appropriate methods of inquiry as adapted from Cross [10] Based on the hypothesis that structural engineering is predominantly a design discipline, the role of the physical model – as an instance of modelling – in structural studies is discussed as a reflection of the mode of reasoning in structural design; the issue in question being whether the lack of conceptual awareness in structural studies is a deficiency of the educational framework, a shortcoming of the method of inquiry or does it relate to the mode of reasoning to begin with and a misconception of the nature of the discipline first and foremost? Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 3. Modelling as a method of inquiry The actual definition of the word model illustrates its multiple roles; definitions ranging from the reference object with qualities worthy of imitation to a scheme of abstraction embodying crucial properties of the empiric reality or a device of reduction carrying information in a smaller scale or a simplified manner. (Coste [9]) In structural engineering practice, in-scale physical models have been for long an important aid in structural studies (Motro [25]), especially in the case of innovative or experimental structures (Gass & Otto [16]), interpreting structural configurations, simulating structural and material performance and providing data that otherwise would be extremely difficult, if not impossible to extract, in order to improve structural efficiency. With the advent of digital technologies and the shift of the role of the computer from a machine executing analytical and drafting tasks to a tool delivering performance simulation operations and comprehensive optimization processes, the contribution of the physical model has been shifted to the size of the full-scale mock-up to inform the design process about structural, material, fabrication and assembly parameters and assist in fine-tuning design variables. In architecture, modelling is an omnipresent element in the design process; be it in the form of a rough sketch, an inclusive diagram, a material artefact, a digital object or a numerical definition. Serving as an abstract artefact to schematize a design concept or a detailed replica to represent a design proposal, an ambiguous ideogram allowing for design associations and interpretations or a concrete device to demonstrate design principles, the model is an essential tool in the architectural design process, apt to assume either roles in an analytic or synthetic mode of reasoning. ‘Du paradigme a la representation, l’architecture fait du modele une utilisation apparemment paradoxale, qui navigue entre l’exercice d’abstraction d’une realite physique et la concretization materielle d’une idée. Pourtant, on a toujours eu recours au modele pour concevoir et pour comprendre.’ (Coste [9]) In architecture education, the physical model, in particular, has a significant place in the student’s toolset, not only as a means of (re)presentation, but as an indispensable medium capable to perform a dual role: resuming and reflective (analysis) or generating and productive (synthesis). From a design perspective, modelling as a method of inquiry acts as a mediator towards the exploration of a pattern within a synthetic rationale. Likewise, the physical model in structural studies is expected to serve as a tool to generate, manipulate, validate or communicate a structural pattern. The present work attempts to comment on the use of the physical model in structural studies within architecture education from this specific perspective. 4. The physical model in structural studies – Case-studies While the context is seemingly quite different from professional practice and research, there are several attributes that sustain the present approach and allow for a certain degree of generalization about the role of the physical model in structural studies. Within the field of architecture education, the use of the physical models is abundant and showcases a wide range of purposes and perspectives, often exploring experimental directions. Furthermore, the omnipresent culture of modelling enables relevant academic discourse. Finally, the particular issue of the role of the physical model as a method of inquiry in structural studies has already been addressed in the specific framework, although discussed in tentative attempts merely from an educational perspective. Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.1. The tradition of the humanities: implying patterns of structural behavior Historically, prominent scholars, educators and practitioners have made of the physical model a key reference for a qualitative approach to structural matters based on visual reasoning; despite the actual format, the devised schemes, vigorous and resourceful, bear dynamic qualities beyond the mere visualization of a structural configuration, rather operating as simulation tools by implying patterns of structural behavior. In these theoretical treatises, the author is making use of the physical model to make an argument or illustrate a theory. These alternative models are used in order to condense and translate the – often elaborate – knowledge, accumulated by practice and on-site expertise, for the general, yet interested or in any case concerned, audience or to reduce to their fundamental essence theoretical concepts for a public novice to structural matters. The physical model works here primarily through the mechanisms of metaphor or analogy – in the tradition of the humanities – by referring to a composition of humans or a common object, mechanism or phenomenon; serving as a sensory medium for processing information in an inductive way within a passive, yet reflective, practice in order to explain the global performance of the structure. 4.1.1. The metaphor – the ‘live-model’: feel/ sense (Figure 2) Figure 2: V. de Honnecourt’s [12] drawings to explain thrust forces in medieval cathedrals [9], Sir B.Baker’s [3] ‘live’ model for the Forth Bridge, F.Wilson’s [33] original illustrations for children 4.1.2. The analogy: recall/ relate (Figure 3) Figure 3: P.Abraham’s [1] ‘intuitive experiment with the ball’ to confront V.le Duc’s interpretation of the structural function of gothic vaults, M.Salvadori [27] illustrating shear forces, F.Moore’s [24] contraption to discuss beam deflection Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.2. The scientific paradigm: demonstrating structural performance In educational activities reminiscent of the scientific paradigm, the physical model is present in the form of a set of carefully prepared devices serving for the execution of a meticulously designed set of experiments to illustrate a range of methodically chosen structural principles or system configurations. While the set of experiments, either as a built-in lab component or as an auxiliary stand-alone activity, has a supplementary position next to the theoretical module of an introductory course in structures, the physical model has an instrumental role as a powerful apparatus to demonstrate in a live manner structural performance patterns under loading for specific structural elements or systems; the two modes showcasing the scope of the educational approach ranging from a teaching activity with roots back to the scientific experiment, yet seeking to expand the behaviorist paradigm by adopting a performative character, to a self-motivated learning activity pertaining in the constructivist realm. The physical model consists here of the ultimate demonstration tool to render tangible abstract theoretical concepts in a direct visual way, enabling to process information in an inductive way from facts to principles. While the contribution of these activities to a qualitative understanding of structural behavior is powerful and irrefutable, questions arise in regards to the pool of chosen or possible experiments, to the rather passive role of the student and the sequential way of building up structural knowledge; issues that the advent of digital technology has come to address with the introduction of educational devices that perform ‘digital’ structural experiments in similar ways. 4.2.1. The experiment: prove (Figure 4) Figure 4: Experiments with physical models performed in a lab component as suggested by Prof.O.Künzle [20] for Building Structures I & II – 1st year course at ETH-Zurich 4.2.2. The composition (kit-of-parts): discover (Figure 5) Figure 5: The MOLA structural kit (Barrato [5]): “simulating real structures” and “allowing users to assemble, visualize and experience the feel of structures themselves” Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.3. In-scale structural models: the role of the precedent In structural studies, physical models are often used to represent in-scale the structural configuration of an entire building structure in order to render explicit the hierarchy of structural components and their dependencies, to depict discrete structural elements and highlight specific structural, technical and material issues. Working with such models is usually within the framework of a concluding project of an introductory course in building structures of an undergraduate curriculum; the learning objective of the assignment being to attest on the ability of implementing skills and competences acquired in the theoretical part of the course. While the principal objective of the course – be it of analytic or design nature – is to critically analyze or efficiently design a building structure within the realm of fundamental structural typologies, the physical model operates as a proof of the student’s capacity to outline, deconstruct or articulate a consistent structural configuration of own design proposal – often paraphrasing a selected precedent – or of a case-study of designated precedents. The primary tools of investigation consist here of analytical or graphic methods for sizing structural members and qualitative diagrams or quantitative reports to estimate internal forces; the physical model acting primarily as a visual tool to demonstrate a global interpretation of the structural design scheme as an outcome of a process of analysis or synthesis. 4.3.1. The precedent analysis: deconstruct (Figure 6) Figure 6: Physical models illustrating the structural configuration of selected precedents – Building Structures II (mandatory 1st year course – Prof.M.Vrontissi [32] – Univ.of Thessaly 4.3.2. The precedent-based synthesis: articulate (Figure 7) Figure 7: Physical models of proposals for a design assignment (footbridge or long-span structure) Building Structures I & II (mandatory 1st year courses – Prof.Dr.Ph.Block [8] – ETH-Zurich (photo courtesy of Block Research Group ETH-Zurich) Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.4. The constructivist paradigm: the ‘learning-through-play’ approach In educational practices following the constructivist paradigm, the student is guided through hands-on exercises to explore basic structural principles or is introduced to the basics of elementary structural components by means of short design competitions; the physical model being an effective tool to materialize the design scheme and render tangible its structural qualities. These activities, usually as part of an undergraduate curriculum in an introductory level and within a limited timeframe, are small exploratory design assignments operating as initiation to structural design and structural efficiency. However, the objective is to playfully familiarize with the structural performance patterns of specific structural elements or configurations and intuitively comprehend the intrinsic characteristics of the structural system or typology in question rather than emphasize on the actual design. The activity is exclusively based on the physical model as an output of a hands-on experimentation in a trial-and-error method. The physical model is a powerful sensory aid to bring concrete evidence, processed in an inductive way – without necessarily understanding the intrinsics of structural performance to all their extent – and ensuring the active engagement of the student. The model performs here its dual role in generating a pattern (synthesis) and reducing it (analysis) to test the proposed scheme in a visual concrete way; its part being instrumental in the generation of the scheme as well as the process of validation. The range of the activities is rather wide, showcasing two principal directions in problem-solving practices: satisficing vs. optimizing; reflected in the framing of the corresponding learning objective, suggesting the design drive and outlining the qualities and variety of outcomes. 4.4.1. The experience: generate (Figure 8) Figure 8: Studying elementary stuctural principles by means of hands-on exercises: exploring isostaticity (Tixier [31]) or testing overall strength and stability (Egg Drop Project) 4.4.2. The in-scale competition: validate (Figure 9) Figure 9: Discussing trusses by means of load testing of spaghetti, straw or popsickle sticks bridges Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.5. The engineering tradition: highlighting or fine-tuning design parameters In a rather experimental approach, often driven from the engineering disciplines, the physical model appears in its full-scale version either as a rough prototype to offer speculative input or as an accurate mock-up to provide targeted feedback for the design scheme or the design process. These activities usually take place in the form of a design-build workshop or an intensive educational module, often functioning within a broader research scope; the role of the instructors being instrumental in guiding the process. The educational objectives remain particularly valid in bridging the gap between theory and practice and fostering a research mindset; the physical model serving as a means to simulate patterns of structural or material performance in a concrete way in order to understand, discuss or validate structural behavior, material properties and construction configurations. The full-scale structure serves as a critical means of the investigation as a stand-alone medium or in combination with other, analog or digital, means, especially in the case of experimental structures, as it has been the case for long in structural engineering practice. However, the role of the model, as defined by the scope of the research-driven activity – often systemspecific – is rather constrained in the scientific realm; the full-scale prototype is used as an exploratory device to offer an empirical proof of concept, while the full-scale mock-up operates as an apparatus for design validation in providing concrete, factual data within a controlled experiment setting. 4.5.1. The full-scale prototype: speculate (Figure 10) Figure 10: Full-scale prototypes in the framework of exploratory design-build workshops in Ateliers Design (ENPC, Paris) [17], ERASMUS-IP [6], Les Grands Ateliers [22] 4.5.2. The full-scale mock-up: inform (Figure 11) Figure 11: Full-scale mock-ups in the framework of research-driven educational modules: a) Master Class Studio at UTS, Sydney, b) The Sequential Structure I & II at ETH-Zurich, c) Funicular Funnel Shell Workshop at ILEK, Stuttgart – all projects with collaboration with Block Research Group ETH-Zurich [8] (photo courtesy of Block Research Group ETH-Zurich) Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 4.6. Full-scale structures: outcome-based vs. process-based approach The full-scale structure is present in yet another instance; this version, however, deviating from the scientific paradigm. Given the challenges of the design brief, asking for a full-scale footbridge, pier, canopy, shelter or pavilion, the endeavor remains within the realm of structural studies; the emphasis, however, is placed towards architectural or structural design or topics related to building technology. While the design-build workshop remains the framework of the work, the focus is shifting away from a research-driven approach, adhering to the educational perspective. The objective is the integration of specific design parameters within a – basic or complex – synthetic scope and the experience of the full-cycle of the design process in the form of an elementary initiation or a mature implementation depending on the level of the participants. When dealing with novice students, the outcome depends on the meticulousness of the execution for the most part; the originality of the design scheme and the resourcefulness of the construction process being by default limited or largely directed. The approach turns out to be outcome-based; performance criteria juggling between optimal structural efficiency and technical feasibility. On the other end, projects addressing senior students with advanced technical competences allow for an open-end approach, outlined by design constraints just as in a real setting, and call for a process-based module fostering creativity and favoring experimentation. The full-scale structure IS here the final outcome of the process – and not a means to an (other) end; the actual physical object being a concrete manifestation of the design scheme, as well as of a certain construction process; it remains, however, a powerful medium by default exploratory for novice or mature students, operating as the field for real-time explorations for both the scheme and the process. 4.6.1. The full-scale competition: construct (Figure 12) Figure 12: Ateliers Design, ENPC Paris: Full-scale footbridges in bamboo, cardboard or timber [17] 4.6.2. The full-scale exploration: materialize (Figure 13) Figure 13: Defis du Bois 2013 (Bignon [7]): “Vogel Holz”,“Smoke on the Water”,“Ame Vagabonde” Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions 5. Discussion – The physical model in conceptual structural design studies From an educational perspective, the contribution of the physical model proves to be instrumental in switching the teaching mode towards the constructivist paradigm; as a medium to transform elementary tasks in structures courses based on the behaviorist tradition to engaging practical problem-solving learning activities. While “most engineering education is auditory, abstract (intuitive), deductive, passive, and sequential” (Felder & Silverman [13]) built on the behaviorist tradition, the physical model, proliferating in architecture education, serves as a visual or tactile means bearing concrete evidence, engaging the student in both actively dealing with and consciously reflecting on the information by implementing an inductive way of reasoning and enabling a global awareness of the issues in question. Nevertheless, if we are to consider the contribution of the physical model in the design process in the reviewed practices, one would rightfully notice that its role is somehow delineated within certain boundaries, not to mention limited to specific tasks. The physical model serves in the process of developing schemes, exploring variations or investigating iterations; the outcome, however, of these operations is often constrained within a certain pool of solutions outlined by the educational or research scope; to state but a few of such constraints: allocated means and timeframe, suggested materials and fabrication method, precedent-grounded approach, typology-founded reasoning, outcome-based assessment. Though this strategy may indeed prove strategically wise for the efficiency of the method and the effectiveness of the tool, it manifests, nonetheless, a scarce, if not none, presence of the physical model in the process of generating a structural concept in the early stages of the design process, even in the form of a rough or tentative hypothesis. Confined within the engineering tradition, the physical model is constrained in a role defined primarily by the scientific paradigm, predominantly used as a tool for a controlled experiment in order to produce ‘data’ within an analytic rationale, seeking for the maximum structural efficiency of the optimal configuration. In the architecture realm academic discourse supports the potential of the physical model as conceptual tool in design studies. In an issue devoted to models as “autonomous objects or structures that evoke associations, interpretation and imagination”, the architecture journal OASE (Holtrop et al. [18]) revokes the concept of the 1976 exhibition ‘Idea as Model’, suggesting models “as studies of a hypothesis, a problem, or an idea of architecture.” In the exhibition catalogue (Frampton & Kolbowski [15]), P.Eisenman, the initiator of the endeavor, adopts the idea of “a model as a conceptual as opposed to narrative tool […] having an almost unconscious, unpremeditated, even generative, effect on the design process”. Figure 14: ‘(A)Percevoir la Gravite’. [ALICE] – Prof. D.Dietz [11] – ENAC, EPFL & ‘Balanceakt’. Structural Design IV – Prof. Dr.J.Schwartz [30] – D-ARCH, ETH-Zurich Proceedings of the International Association for Shell and Spatial Structures (IASS) Symposium 2015, Amsterdam Future Visions In architecture education, recent practices deviating from the prevailing paradigm, foster conceptual structural studies based on the physical model, borrowing an example from the arts (P.Fischli & D.Weiss, Equilibrium Series); unexpected compositions of otherwise trivial objects express unconscious, unpremeditated structural patterns within a synthetic scope (Figure 14). The present overview illustrates the poor presence of the physical model as a tool for conceptual structural design studies; however, the study suggests that this is neither a deficiency of the particular educational setting or isolated pedagogical strategies – shown as successful from an educational perspective – nor a shortcoming of the method of inquiry or the tool – discussed as effective for specific design tasks and otherwise suggested as apt for conceptual studies. The study argues that, if closely examined, this is a reverberation of the actual lack of conceptual structural design studies in architecture education in the first place; reflecting probably the trend in structural engineering education and possibly the prevailing paradigm in practice; revealing an analytic rationale in structural studies and a mode of reasoning confined in the scientific paradigm. 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