A Structural Basis for Surface Discretization of Free Form Structures: Integration of Geometry, Materials and Fabrication.

Free Form Surface Structures;Planar Quadrilateral Meshing;Architecture;Arts;Architecture

Berk, AysuBoland, Patrick ;

University of Michigan

关键词: Free Form Surface Structures;    Planar Quadrilateral Meshing;    Architecture;    Arts;    Architecture;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/96115/aysuberk_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This study focuses on free form surfaces and the challenges of construction due to the complex geometry. A unique approach is proposed that incorporates attributes of form, material selection and fabrication methods of free form surfaces into the early stage of design in aid of optimum mesh generation towards redesigning a practically constructible structure.Free form surfaces need to be discretized into panels with manageable sizes so that the surface can be fabricated in smaller pieces that are all assembled on site. Planarity has been a significant constraint for free form discretization because brittle materials, such as glass, can fail suddenly, without any warning. Triangulation has been a common pattern for free form surface discretization, where the panels are always planar. Due to node complexities of triangulated meshing, quadrilaterals are considered as an alternative pattern for free form surfaces. However, the biggest problem with quadrilaterals is that quadrilaterals do not always form planar faces. A method to generate and apply quadrilateral meshing on free form surfaces is introduced in this study where pre-deformed (non-planar) quadrilateral panels are proposed to be used at high curvature areas of the complex surface where planar meshing is not possible. In this study, structural tests and simulations are conducted on quadrilateral panels to find out the limits of surface curvature allowed for specific materials. The analyses demonstrate the behavior of quadrilateral panels under uniform wind load, pre-deformation load and finally a combined load case, which considers wind load on pre-deformed panels. The behavior of quadrilateral panels under pre-deformation is observed, and the relationship between this pre-deformation amount and the related structural and geometric design parameters, such as panel size, thickness, and material properties is investigated. The limiting curvature value for any design then can be determined using these relationships. The results of the study also demonstrate that this pre-deformation acts as pre-tensioning that increases the capacity of the panels to carry more with less deflection.