Soft architecture. CBA-CFS : complex bending-active hybrid structure introducing the use of spacer fabrics in the architectural field

This thesis aims to provide an approach for development a new architectural space. Soft and welcoming, easily transformable and extremely lightweight in terms of perception and construction. This kind of spaces are highly requested in a modern world with growing speed of life, tendency to the temporary solutions and trends of sustainability in architectural approaches. This goal became a basis for a research into the direction soft and light materials of architectural and other fields, and a study of existing mold-less structures processing aesthetic qualities of visual softness, mainly soft curvatures of its surfaces. This kind of constructions is commonly attributed to the structural type actuated by active bending. Thus an investigation was done on active-bending structures. The main insight of this work lays in coupling the material and geometrical aspects of the structure. This two tightly connected qualities define a new structural type and building system. The proposal based on derivation of non-architectural material into architectural sector after scaling its inner geometry and careful design, which allowed to create a system, where a covering soft material became structural. This resulted in appearance of a new, fully made with soft materials, structural system named СBA-CFS (i.e. complex bending-active continuous flexible sheets), developed by the author. The СBA-CFS is an innovative structural system based on interactive work of tensioned and bended elements equilibrating each other, made with soft materials. The structural system implies the behavior of elastic sheet material pre-stressed by active bending, thence the investigation is referred to almost unlearned structural field. Blind sheets of common materials used for bending-active structures are basically hardly yield to the complex bending, nevertheless use of particularly customized material with a high grade of elasticity doesn’t require introduction of holes or cuts in the surface to allow the bending process. Since the all the materials used are soft, each element of the system is unstable alone but while working together create a shell rigid enough to bear self-weight and additional distributed loads. Principal acting elements of the structure are a composite elastic material based on spacer fabric and system of membranes working on tension and deforming the spacer sheet in a desirable configuration. In order to create a structurally efficient shape from the point of view of stress distribution, mentioned deformations occur in buckles which follow the direction of maximum compressive stresses. Instead, tensioned membrane system is placed in a proper direction to resist maximum tensile stresses. Moreover, the depth of the buckles depends on the quantity of stress in each part of the shell. This complex process of optimization the buckles carried with the Finite Element (FE) solver of Millipede for Grasshopper by analyzing general yet not buckled shape conceived by the designer. The final preview of the shape and dynamic behavior of the structure is done through form-finding simulations based on Particle Spring Systems (Kangaroo 2). After a few cycles of optimization an aesthetic and relevant architectural shape can be produced using the CBA-CFS method. The design methodology of this system and the research path is explicitly described in following chapters. Anticipating this part of the thesis, a consistent discussion on series of prototypes produced during the investigation is given, as well as detected problems and solutions related to the production and structural work. The last part dedicated to the development of the detailed project of a temporary multifunctional shelter implementing the CBA-CFS system. Design of an exact shape, especially in a bigger scale usually meets some particular problems that were not found on previous stages of trials and method definition. Such issues as manufacturing of 1:5 model, tailoring irregular buckles, logic of prefabrication and installation process as well as development of the support system is given in the “Project” chapter. The work concluded by summing up the advantages, disadvantages and particular features of the system. In relation to this providing considerations for further development and use of the system, defining possible variations and vectors of the further research.