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This paper discusses the application of a Multi-Objective Search method to the design of shell structures. Contrasting objectives of lightweight and high stiffness are considered for two case studies with different geometry and constraints. The Multi-Objective search is performed in the frame of the Pareto theory of non-domination, implemented in the NSGA-II algorithm. The research focuses on the way a designer can interact with the search computational procedure, driving it towards the desired solution. Diversely from pure optimization techniques, search strategies as Multi-Objective search produce sets of feasible solutions, which the designer can evaluate and use it their work, accordingly with other architectural requirements and purposes.

This paper deals with a multi-objective design/optimization grid-shell problem. Structural behavior and light absorption/shading have been selected as fitness functions. Such performance criteria can separately lead to different and divergent optimal solutions but, if they are considered as a whole, they are expected to result in several equivalent or similar sub-optimal shapes. This multi-objective optimization problem has been performed here with the aid of a Genetic Algorithm (GA). GAs explore and search widely for suitable solutions and, in this way, they become design tools rather than solution ones. Three benchmarks were established and then a more complex application was made to an existing case study, i.e. the Esplanade in Singapore, designed by DP Architects (DPA) and Michael Wilford & Partners (MWP).

This paper deals with the design of reciprocal spatial configurations, based on the use of planar elements, which are investigated and classified according to their morphological characteristics and design potential. Reciprocal structures were first originated as assemblies of elongated elements. In Europe, the concept of spanning longer distances than the length of the available timber beams was the key reason for the use of such structures, which were therefore called ‘short-beams’. In the East and especially in China, the use of interwoven strips of bamboo for the construction of baskets is an old tradition that was transferred to larger scale objects, and which has also led to the development of reciprocal configurations based on linear elements. In this framework, a study of reciprocal systems, based on the use of 2D planar panels, is proposed. A first morphological classification of reciprocal systems based on planar elements, which have been divided according to the shape of the elements and growth possibilities of their assembly, is provided. Moreover, some research issues for future investigations are highlighted. The presented systems and prototypes were developed by students at the École des Ponts in Paris during their Master’s degree and a workshop run by the authors in March 2012.

This paper deals with the design of reciprocal spatial configurations based on the use of planar elements, which are investigated and classified according to their morphological characteristics and potential. Reciprocal structures are generally designed with the use of linear elements. Since their historical conception, at least in Western culture, they have been strictly related to the use of short timber beams to cover large spans. This structural principle is described for instance by Villard de Honnecourt, who drew in his sketchbooks reciprocal grillage assemblies for the construction of floors, between 1225 and 1250, followed by Sebastiano Serlio in 1566, John Wallis in 1695, and it can be still found in several treatises of carpentry, written during the XIX century. From the morphological point of view, reciprocal structures have been generally used to develop bridges, slabs, domes and shells. We could conceptually refer to the first case linear developments. Examples are the so-called ‘Rainbow Bridge’ in Shandong or the Leonardo’s concept for a bridge structure. In the second and third cases we could refer to a two-dimensional development, since they can be conceptually conceived and represented as surfaces. Several examples have been built by the architects Ishii, Kijima and Kan. In architecture, reciprocal structures are rarely used due to a set of practical issues. Their simple technology allow a simple and rapid construction,. However, problems related to spatial complexity, structural calculations and cladding, generally encourage designers in exploring other structural typologies, making their use suitable just for temporary or experimental structures. In this framework, the authors propose a initial study of reciprocal systems based on the use of non-linear elements, i.e. 2D planar panels. Such configurations are classified in this paper according to the shapes and properties of their composing elements. For example: (1) most of the planar elements can generate the same configurations of beam elements; (2) some planar elements can be disassembled in two or more linear elements forming a similar configuration; (3) some planar elements can be composed in order to take advantage of their shape peculiarities, for structural or construction purposes. Configurations belonging to this category could be also referred to the previous ones. The presented categories are supported by drawings and photographs of prototypes, also realized with the contribution of the students of the École des Ponts in Paris (developed during a workshop run by the authors in March 2012) and the University of Melbourne.

In: "Bloom", vol. 14, pp. 17–24.

Original Italian abstract (English text below):

Negli ultimi vent’anni l’impatto del digitale in architettura è cresciuto esponenzialmente, manifestandosi nei ‘BLOB’ informi di Greg Lynn1, come anche nelle cosiddette ‘free-form’ dei NOX2. L’aggettivo ‘free’ identifica la libertà di generare forme architettoniche a prescindere da ogni principio compositivo, statico o costruttivo, e si estremizza, ad esempio, nella ‘trans-architettura’ puramente virtuale di Marcos Novak3. Il computer insidia il lavoro concettuale del progettista come la realizzazione delle sue opere. Attraverso la fabbricazione a controllo numerico, il ‘file-to-factory’, il gruppo Objectile4sfida la produzione seriale dell’industrial design. Così un unico modello digitale parametrico si concretizza in molteplici variazioni spaziali uniche, sempre nuove.

English translation:

Over the last twenty years, the impact of the “digital” inarchitecture has grown in an exponential manner, as demonstrated by Greg Lynn’sinform “BLOBs” and by the NOX “free-forms”. The adjective “free” here indicatesthe freedom to create architectural forms, irrespective of any composition,static or construction principle, and has been taken to an extreme in thepurely virtual “trans-architecture” of Marcos Novak. The computer threatens theconceptual work of designers, as well as the realization of their works.Through Computer Numerical Control (CNC) fabrication, the so-called“file-to-factory” process, the Objectile group has challenged the serialproduction of industrial design – a single parametric digital model can now bematerialized in a multitude of unique spatial variations without a significantincrease in costs.

Read the entire English text here.

This paper presents seven different three-dimensional structures based on the principle of structural reciprocity with superimposition joint and standardized un-notched elements. Such typology could be regarded as being intrinsically three-dimensional because elements sit one on top of the other, causing every configuration to develop naturally out-of the plane. The structures presented here were developed and built by the students of the Master of Science in "Architectural Design" during a two week long workshop organized at Aalborg University in the fall semester 2011.

This paper discusses the teaching of technical subjects in architecture, presenting two experimental activities, recently organized at Aalborg University - a two-week-long workshop and a one-day long lecture. The activities are strategically placed between seminar-based subjects and architectural design studios, from the pedagogical point of view. On the one hand, this allows a better mix of theoretical lectures, exercises and design practice; on the other hand, narrow topic related to structural design may be deepened on the basis of a research-based approach to design.

In this paper, the design of a free-form roof structure is presented, approaching the problem in order to reduce construction costs and to define an efficient structural behaviour. The design process is supported by the use of a parametric tool, Grasshopper, for the definition of an optimization problem related to shape-resistant structures, and then a Genetic Algorithm, Galapagos, is used to explore/improve the shape of the 'a priori' defined structure, or better a parametric solution domain of tentative structures. Finally, a scripting interface between the CAD software, Rhinoceros, and the FEM solver, Autodesk ROBOT, is described as a rapid way to check and refine the structural behav-iour of the overall roof.

This paper deals with the principle of structural reciprocity, considering its origins in both Occidental and Orient culture and aiming to highlight the definition, main characteristics and interesting aspects of such concept referring to its application to the world of construction. Issues spanning from history, form-finding and morphology, structural behaviour and construction techniques are discussed in the paper, which should be considered as a starting point to stimulate future research and design directions/approaches.