2008 Structural Engineering Traveling Fellowship
Aesthetics and Physical Models

Physical models have vast potential as visual, analytical, and design tools for the study and creation of aesthetically pleasing, technically challenging, efficient structures. Models are an ideal way to develop structural solutions through a balance of discipline and play. [1] Discipline as it pertains to structural design is the understanding of structural behavior and economic and material constraints, whereas play represents an exploration of form. For elegant forms to be efficient and economical to build, discipline should accompany play.

The Swiss engineer, Heinz Isler, engaged in a design process that exemplifies this balance; his process involved generating a series of models from which the form of the full-scale structure followed. In addition, Isler viewed completed works as opportunities to reflect on the process of design as well as a means of checking that the predicted results were reasonably achieved. Isler states that form-finding is only “the first link in a whole chain of investigations and the other links in the investigation are model tests, measuring of the first structure, 1:1 as we have it out [t]here; these are of primary importance.” [2] Isler’s process is tied to a physical understanding of behavior, and the Sicli Factory in Geneva, a free-form shell with seven supports, clearly demonstrates his methodology. To develop the complex form for the Sicli Factory, Isler created a series of hanging models, small-scale experimental models from which he could examine shell stresses and buckling capacity, and an architectural site model.

Concerns about long-term behavior led Isler to monitor the deflections of the Sicli Factory for almost twenty years after its completion. [3] Performance of the completed structure, not the complexity of the analysis, dictates a structure’s success. Isler, like other great structural artists relied on physical intuition gained from first-hand observation.

Today most physical modeling has been replaced by computer modeling. While the computer is an invaluable tool, it can compromise the development of one’s intuition about how structures behave. This report identifies how physical models have been used as visual, analytical, and design tools to create aesthetically pleasing, technically challenging, efficient structures both before and since the emergence of computer modeling. Physical models as complements to computer models still benefit practitioners today and promote more creative and rational form generation among college students as they prepare to become structural designers.

Conclusion

This report identified how physical models have been used as visual, analytical, and design tools in the past and suggested that despite the emergence of computer modeling, physical models can still benefit practitioners today. After the successful completion of a structure an engineer might commission a display model of the work. While display models may draw public attention to and allow engineers to reflect on their works, using visual models and prototypes during design can stimulate ideas and lead to unexpected changes. The physical model of the Severin Bridge is an exhibition model, but a similar model used early in the design process can give feedback about a structure’s proportion and relationship to its site. Computer graphics are also important in visualizing and refining a structure’s overall form and details and should complement physical models where modifications need to be realized quickly. Structural engineering like architecture is a visual art; generating study models and performing visual critiques should be as important in engineering as it is in architecture.

In contrast to visual models, which are more widely used by architects than engineers, analytical models have long been embraced by engineers for analyses too complicated or time consuming to perform by hand. Computer modeling has replaced physical modeling for well understood problems such as statically indeterminate network-tied arch and cable-stayed bridges, but not for predicting a structure’s wind response. For example, the Swiss Re Headquarters in London, completed in 2004, was tested by Rowan Williams Davies & Irwin (RWDI) in a wind tunnel. Computational fluid dynamics (CFD) continues to improve and give results closer to those observed physically. It is conceivable that CFD will eventually be reliable and quick enough to replace physical modeling. However, new forms and new methods of analysis will arise and require verification by physical means first.

Even the most well-conceived physical and computer analytical models can only approximate behavior and should complement simple hand calculations. If analysis is at best an approximation than some forms are easier to approximate than others. David Billington, when referring to the wide range of visually interesting shell forms that were generated by individuals who relied on and developed simple rather than complicated analysis techniques, notes that shells “carry forward the central scientific idea in structural art: the analyst of the form, being also the creator of the form, is free to change shapes so that complexity disappears.” [4] Here Billington does not mean that structures should only take on well-studied forms, but rather is emphasizing that engineers rely on experience to avoid unnecessary complications when creating new forms. Form-finding models like hanging chains and membranes and soap film take on rational forms and suggest how their full-scale equivalents will behave. These models may be of vastly different materials and scale than the final structure and therefore appear more like an abstraction than a facsimile. Engineers still need to exert judgment when assessing the validity of a form-finding technique, but the models are meant as a point of departure from which additional visual and analytical models are developed and used iteratively to inform the final design of a structure. Today, computational form-finding has replaced most physical form-finding and while physical form-finding is still informative as a means of developing intuition, physical modeling has a more direct benefit for the design of moveable and adaptable structures.

Physical models as complements to computer models have potential as visual, analytical, and design tools. At the small-scale one can generate and refine forms while approximating behavior. However, only at the full-scale can one make a proper aesthetic critique and confirm that the form safely carries the loads acting on it. For Isler, studying his completed works was an important part of his design process. Isler viewed each structure as an opportunity to reflect. This reflection is another form of discipline or striving to understand behavior and material constraints that informed his play or his future exploration of rational form. Today many of Isler’s shells like the BP Gas Station completed in 1968 and Bürgi Garden Center completed in 1971 are still used and are in excellent condition proving not only the success of these structures, but also the success of Isler’s process.

Isler, like other great structural artists relied on physical intuition gained from first-hand observation. Today most physical modeling has been replaced by computer modeling; however, computer modeling can compromise the development of one’s physical intuition. Because practitioners are more likely to use computer models than physical models, this physical intuition has to begin to be developed in college through the use of physical visual, analytical, and design models. Many institutes both abroad and in the United States already incorporate visual and analytical models into their curriculums, but more emphasis should be placed on creating design models as a means of generating more creative and rational forms and understanding the balance of discipline and play required to create efficient, economical, and elegant structures.

Student visits to built works and with practitioners should complement design exercises. In Europe, some practitioners are also full-time university faculty providing students with a mix of theory and practice in the classroom. However, in the United States while this is typical for architects it is not as common for engineers. As a result, universities in the United States usually emphasize theory and analysis rather than design. While this approach may teach students about fundamental structural behavior and how to analyze a particular set of members, it does not inspire creativity or elicit thinking about globally efficient forms. Visiting aesthetically pleasing built works and meeting with leading practitioners reassures aspiring engineers that the potential for new, visually interesting, and efficient forms exists. Physical models can help students and practitioners realize this potential.

Notes

[1] Concept presented in David P. Billington, The Tower and the Bridge (Princeton: Princeton University Press, 1983), 213–32.

[2] Heinz Isler, “New Shapes for Shells,” Bulletin of the International Association for Shell Structures 8 (1961): 123–30.

[3] John Chilton, The Engineer’s Contribution to Contemporary Architecture: Heinz Isler (London: Thomas Telford Publishing, 2000), 99.

[4] Billington, The Tower and the Bridge, 20.

Denmark, Norway, and UK

Germany

Switzerland

Spain

Fellow Experience

A Conversation with Edward M. (Ted) Segal
October 1, 2025

Edward M. (Ted) Segal, associate professor of engineering at Hofstra University, works at the intersection of art, design, technology, and teaching. In a recent conversation, Segal shares how his design/research team at Hofstra approaches material exploration in novel ways, discusses the importance of fostering curiosity and collaborative exploration with his students, and describes how the research he conducted on modeling during his 2008 Structural Engineering Traveling Fellowship remains relevant to his work today.

This interview, conducted by Molly Hanse, is part of a series of conversations that explores how SOM Foundation fellows are shaping the future of their fields.

Looking back to your 2008 Structural Engineering Traveling Fellowship, what stands out to you most about that experience?

When I received the fellowship, I did not realize how much I would continue to draw from my travel and research across my entire career. The focus of my fellowship was studying European physical modeling and testing laboratories as well as the structures that emerged from those facilities. The objective of this research was to identify potential roles for physical models as complements to computational models in design and education.

At Hofstra University, where I’m currently an associate professor of engineering, my program only has undergraduate students. I teach undergraduate courses, and my design/research group is made up entirely of undergraduates that I may only work with for a few months. Both inside and outside of the classroom I have found that working with physical models allows us to accomplish a lot more than if we were working primarily on the computer. For example, my senior design course is structured like a studio. In the course, the students review various precedent works (including ones that I visited while traveling) and then develop their own designs using physical form-finding methods that I studied as part of my fellowship. While many of these students are studying structural engineering, some are studying environmental engineering and may not have taken many structures courses. Using physical models allows students from a range of backgrounds to quickly create complex, yet efficient forms. After just a few weeks into the semester they are able to propose ambitious projects.

Recently, I have also been developing a cross-disciplinary course, “Drawing Across Disciplines Abroad,” with Professor Jim Lee in fine arts. As we put together the course I have been pulling from my fellowship travel itinerary. I am looking forward to revisiting locations and structures that I first visited over fifteen years ago.

Tell us about your career trajectory and how you got to where you are now.

I received the SOM Foundation Structural Engineering Travel Fellowship in 2008 while I was completing my Master’s degree in structural engineering at Princeton University. After graduating, I moved to New York City and worked as a staff engineer at Simpson Gumpertz & Heger (SGH) where I primarily worked on the design of new glass and metal enclosures. After my first few months at SGH I realized that I missed the teaching I had been doing in graduate school and reached out to Professor Maria Garlock there to see if I could teach part time. I was able to coordinate my schedule so that each spring I could take one day per week and teach. While I enjoyed the design office, it became clear that my favorite day of the week was the one when I was teaching.

In 2011, I returned to Princeton to work on my PhD with Professor Sigrid Adriaenssens. The focus of my research was understanding the behavior of suspended footbridges built from an unconventional bridge material, polyester rope. I also had the opportunity to continue teaching while completing my PhD.

In 2015, I was hired as an assistant professor of engineering at Hofstra University and in 2022, I became an associate professor. At Hofstra I work on experimental projects that involve both research and design and teach courses across the engineering curriculum. One of my focuses over the last few years has been collaborating with faculty in fine arts and engineering as well as the director of the Hofstra University Art Museum to create new opportunities at the university at the intersection of art, design, and technology. These kinds of projects are some of the highlights of working at a university that is supportive of cross-disciplinary collaborations.

Could you share more about the Segal Structures Group, and describe a few key projects that the group has done and is currently working on?

The Segal Structures Group is my design/research team at Hofstra. We often collaborate with architects, artists, and engineers on competitions and other projects at the pavilion and installation scales. Our work frequently involves utilizing materials in novel ways to develop engineering/architectural structures. One project, Cast & Place, was an experimental design-build pavilion that won the 2017 City of Dreams competition and was temporarily installed on Governors Island (New York, NY). The pavilion featured a set of panels that were created by casting recycled aluminum into cracked clay patterns. The method generated a series of unique panels without the materially intensive positive patterns required in traditional sand casting.

A second experimental design-build pavilion project, Two Blue Shells, was exhibited at the Form and Force Expo (International Association for Shell and Spatial Structures Symposium and Structural Membranes) in Barcelona, Spain in 2019. The structure consisted of two pink discretized scrap acrylic shells. Originally, the acrylic was anticipated to be blue, which led to the project name. The project was innovative because the shells were formed at the full scale by transforming flat tiles into curved surfaces without molds through heating in a walk-in oven.

My collaborators and I have continued our exploration of building and form finding with scrap acrylic (both acrylic and polycarbonate proliferated during the COVID-19 pandemic) and in 2022 we displayed a prototype, Acrylic Pixel, at the 5th International Conference on Structures & Architecture in Aalborg, Denmark. Additionally, with my students I am now exploring heat-based form finding at the full scale with 3D printed polylactic acid (PLA) grids and with wood gridshells featuring acrylic connectors. The projects shown below will be on display at the 2025 International Association for Shell and Spatial Structures Symposium in Mexico City, Mexico in October. At a small-scale we are developing a method for designers to rapidly create funicular (or nearly funicular) design models using 3D printing pens and an oven. This kind of form finding evolved from the research I conducted while traveling on my fellowship.

My group is also developing footbridges that can be rapidly deployed during flooding for rescue efforts and/or to repair walking networks. Specifically, the footbridges are being designed so that they can be constructed from only one side of the crossing (i.e., the second side is not initially accessible). Unconventional support structures such as trucks or trees anchor the bridge. Deployment relies in part on a manually controlled drone. We are currently working to make our deployment method adaptable to a wider range of conditions.

What changes have you seen in civil engineering over the course of your career? What’s on the horizon for the field?

Since much of my work involves physical modeling, I follow its trajectory alongside computational modeling. In 1997, the Swiss engineer Heinz Isler, known for designing his structures with physical models, wrote the article “Is the Physical Model Dead?” In the article, he makes the case for why physical models are still critical to the design process. In the last five years there have been at least two comprehensive books discussing the various roles of physical models.

Computational modeling is an important part of modern design, but physical models continue to be used. Advances in digital design and fabrication have created new opportunities for integrating physical models into the design process. With the rise of AI, the roles of physical models may change, but I believe they will continue to be used in design and education. Many people crave making things. Gathering in-person with others and creating physical objects is a balance to their online/digital lives.

The evolving relationship between physical and digital models is happening against the backdrop of a much larger concern, the climate crisis. From historic preservation efforts to the use of alternative materials to a heightened focus on circular economies there are many groups working in important ways to maintain, improve, and design new sustainable infrastructure. While my design/research group is thinking about the environmental impact of our larger design projects, we are also looking closely at how we are making our small-scale physical models to reduce waste.

As a professor, what are some key takeaways you hope your students learn before they embark on their careers?

I try to model curiosity for my students. I am open with them about what I don’t know and what questions I have. In many of my design/research projects my collaborators and I lay out an ambitious plan and it seems like we back ourselves into a corner and have to find our way out. Over the last few years, I have been encouraging students to do the same thing by tackling challenging projects. Initially it feels daunting, but they get through by asking questions and seeking answers across fields.

With my students I also try to take on the role of curator. We are all being bombarded by algorithms which are pushing specific content in our direction. I try to introduce them to precedents and ideas that they might not be exposed to otherwise. My master’s advisor, Professor David P. Billington, was masterful at telling engaging stories that drew not only from engineering, but also art, history, etc. He modeled for me what it means to study a range of sources. I don’t want my students to settle for what they are receiving in a feed online. I want them to see the wider world and how they can stitch it together through their own exploration of how items connect.