CAREER: Geometry and Mechanics of Textile-Based Structural Design

Trustees Of Boston University, Boston

Investigators

Abstract

Advances in rapid prototyping have had a profound impact on fabrication, by enabling individuals to engage in the design and manufacturing pipeline. However, the technology has primarily focused to date on small build volumes; creating large, durable, and high-quality objects at the size of sculptural and architectural construction is still impractical for all but highly trained experts. Combining state-of-the-art techniques in computer graphics, optimization, and mechanics, this research will lay the algorithmic foundation for introducing textiles in large scale fabrication by exploring their innovative use for fabric formwork: a molding and casting procedure for 3D shapes. The formwork consists of a flexible fabric membrane whose deformation is governed by equilibrium of the membrane boundary and fluid pressure from the casting material (typically plaster or concrete). The procedure is capable of producing objects with freeform curved surfaces using minimal material and at a range of scales up to full span architectural beams and columns. Textiles offer benefits as a lightweight, economical material that can easily form curved surfaces and span large areas, so project outcomes have the potential to dramatically transform how objects are built (for example, consider shipping rolled up fabric formwork to a remote village to build a concrete shelter, where only a simple supporting frame must be constructed on site). Broader impacts, including affordable construction in economically less developed countries, sustainable construction methods for shaped concrete beams, and membrane structures for medical protective equipment, will be explored through a selection of design case studies, Three tracks will explore the full design-to-fabrication workflow of fabric formwork. (1) The central contribution is a novel optimization framework that poses fabric formwork as an inverse shape design problem. Given a target shape, the goal is to navigate the complex space of design options including 3D rest shape computation, surface patterning and segmentation, positioning of external supports, and orientation and boundary conditions during casting. (2) Patterning techniques will be studied for constructing the 3D membrane surface with textiles. The goal is a generalizable method for free-form 3D shapes with complex geometry and topology. Surface segmentation into 2D developable panels will be studied to allow construction from flat sheets. Alternatively, to provide additional possibilities for locally varying elasticity 3D surfaces may be constructed directly using machine knitting procedures. (3) Drawing upon cognitive principles in perception and domain knowledge in traditional garment making, algorithmic techniques will be investigated for generating visual assembly guides for the final construction phase. Strategies will be developed for the sequence of assembly (the order in which parts are built), along with visualization techniques for communicating assembly instructions. Evaluation will include analyzing 3D scanned reconstructions of physical prototypes and performing user studies to assess the effectiveness of the design platform. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.