Third-year PhD student Yefan Zhi, has won the Hangai Prize at the International Association for Shell and Spatial Structures (IASS) Annual Symposium 2025. Yefan and Dr. Masoud Akbarzadeh, co-authored the paper “Surface-Toolpath Twins of Shell Components in 3D Concrete Printing for Optimized Buildability and Surface Quality”.

In this study on the fabrication rationalization of 3D concrete printing, Yefan introduces surface-toolpath twins that can be interconverted and synchronized through efficient slicing and surface reconstruction algorithms, allowing for the combination of optimizations and modifications on either part of the twin in flexible orders. Global buildability optimization and local surface quality optimization methods are introduced and integrated. The proposed framework enables the integration of form-finding expertise with fabrication-oriented design, allowing the realization of spatial shell structures with complex topologies or extreme geometrical features through 3D concrete printing.

The living past as a source of innovation – IASS (International Association for Shell and Spatial Structures) Annual Symposium 2025 was held in Mexico City, Mexico from September 19th through the 23rd. In memory of Professor Yasuhiko Hangai (Japan, 1942-1998), a very active member of the IASS and its Executive Council, and in accordance with his career-long encouragement for young people, the Hangai Prize recognizes talented young researchers, designers, and engineers working in the field of shell and spatial structures. This recognition is achieved by selecting outstanding submissions to the Annual IASS Symposium in the form of research papers, resumes of design projects, or innovative ideas. Each year, four researchers under the age of 30 are recognized by the Hangai Prize.