Research On Form Generation Of Architectural Curved Surface Based On Structural Performance

As the separation of architecture and structural engineering deepened,traditional methods such as physical form-finding and graphical statics found the way of combining architectural form and structure.Nowadays,with digital form-finding,digital graphic statics,topology optimization and morphology optimization,the digital structural performance-based theory is emerging.The aim of this paper is to find the inherent unity between traditional and digital form-finding theories.The paper also aims to construct the theoretical system and workflow of digital form generation of architectural curved surface.Firstly,based on traditional physical form-finding experiments,the paper summarizes form-finding methods of 2D catenary arch and 3D catenary nets which can date back to Hooke’s catenary theory.The soap film experiment is categorized by different boundary conditions and shapes.Then,after introducing the algorithm principles of Kangaroo plugin of Grasshopper,the paper explains the principle and example of traditional form-finding methods by digital tools.Two traditional form-finding methods,namely catenary model and soap film experiment,are integrated by ‘zero bending moment’ structural property.Furthermore,it demonstrates the inherent unity of traditional and digital form-finding methods and establishes the theoretical system of digital form-finding.Secondly,as contrast with generating form by mechanics,the paper explains the trend of free-form architecture and the ‘post-rationalization’ mode in structural analysis.Then,the principles and advantages of morphology optimization based on FEM method are summarized.The logic of morphology optimization algorithm and genetic algorithm in Grasshopper are introduced.Following that,after introducing principles of Karamba plugin in Grasshopper,the paper constructs the framework of combining Karamba and Galapagos/Octopus plugins so as to morphology optimization and screening.The theory is then verified and extended by shell examples.Thirdly,the paper proposes the workflow of form generation in curved surface architecture,including design concept,initial form,structural concept,physical model and digital model.Considering form,structure selection,material and load,different digital form generation methods are integrated.According to applications and features,various tools in form generation are compared.From the aspects of tectonic theory,balance of structure and form,architectural materiality,a comprehensive evaluation system for curved-surface architecture is established.Finally,the digital form generation of architectural curved surface based on structural performance is verified by two design works.