Tag: structural-patterns

Geometric patterns, pioneered centuries ago as a dominant form of ornamentation in Islamic architecture, represent an abundant source of possible topologies and geometries that can be explored in the preliminary design of discrete structures. This diverse design space motivates the coupling between Islamic patterns and the form finding of funicular grid shells for which structural performance is highly affected by topology and geometry. This thesis examines one such pattern through a parametric, performance-driven framework in the context of conceptual design, when many alternatives are being considered. Form finding is conducted via the force density method, which is augmented with the addition of a force density optimization loop to enable grid shell height selection. A further modification allows for force densities to be scaled according to the initial member lengths, introducing sensitivity to pattern geometry in the final form-found structures. The results attest to the viable synergy between architectural and structural objectives through grid shells that perform as well as, or better than, quadrilateral grid shells. Historic and cultural patterns therefore present design opportunities that both expand the conventional grid shell design vocabulary and offer designers an alternative means of referencing vernacular traditions in the modern built environment, through a structural engineering lens.

The layer-based technique of the fused deposition modeling (FDM) additive manufacturing process creates anisotropy within printed parts, but the full quantitative characterization of this anisotropy is not yet available, making it difficult to predict structural performance of printed parts. This research studies the tensile strength of ABS plastic created by FDM in incrementally rotated orientations, to analytically and experimentally characterize the anisotropy of the material. The known relationship between strength and orientation can then be used to create a predictive model of the local material behavior in any FDM printed object.

Principal stress lines, which are pairs of orthogonal curves that indicate trajectories of internal forces and therefore idealized paths of material continuity, naturally encode the optimal topology for any structure for a given set of boundary conditions. Although stress line analysis has the potential to offer a direct, and geometrically provocative approach to optimization that can synthesize both design and structural objectives, its application in design has generally been limited due to the lack of standardization and parameterization of the process for generating and interpreting stress lines. Addressing these barriers that limit the application of the stress line methods, this thesis proposes a new implementation framework that will enable designers to take advantage of stress line analysis to inform conceptual structural design. Central to the premise of this research is a new conception of structurally inspired design exploration that does not impose a singular solution, but instead allows for the exploration of a diverse high-performance design space in order to balance the combination of structural and architectural design objectives. Specifically, the thesis has immediate application for the topological design of both regular and irregular thin shell structures predominately subjected to in-plane and compressive structural actions.

The project presents a new integrated software and hardware process that reconsiders the traditional addive manufacturing (AM) technique of fused deposition modelling (FDM) by adding material explicitly along the three-dimensional principal stress trajectories, or stress lines, of 2.5-D structural surfaces. Using a six-axis robotic arm, this project materializes continuous stress fields into discrete structural topologies, rendered computationally as robotic tool paths. The goal of this project is to develop and perfect this new technique, and to explore conditions in which it is favorable to conventional layer-based additive manufacturing. The research is supported by methodologies including computational structural analysis and comparative structural load testing. For more video information, see this YouTube video.

Principal stress lines, which are pairs of orthogonal curves that indicate trajectories of internal forces and therefore idealized paths of material continuity, naturally encode the optimal topology for any structure for a given set of boundary conditions. Although stress line analysis has the potential to offer a direct, and geometrically provocative approach to optimization that can synthesize both design and structural objectives, its application in design has generally been limited due to the lack of standardization and parameterization of the process for generating and interpreting stress lines. Addressing these barriers that limit the application of the stress line methods, this paper proposes a new implementation framework that will enable designers to take advantage of stress line analysis to inform conceptual structural design. Central to the premise of this research is a new conception of structurally inspired design exploration that does not impose a singular solution, but instead allows for the exploration of a diverse high-performancedesign space in order to balance the combination of structural and architectural design objectives.