Paul Nicholas

A Multiscale Adaptive Mesh Refinement Approach to Architectured Steel Specification in the Design of a Frameless Stressed Skin Structure

This paper describes the development of a modelling approach for the design and fabrication of an incrementally formed, stressed skin metal structure. The term incremental forming refers to a progression of localised plastic deformation to impart 3D form onto a 2D metal sheet, directly from 3D design data. A brief introduction presents this fabrication concept, as well as the context of structures whose skin plays a significant structural role. Existing research into ISF privileges either the control of forming parameters to minimise geometric deviation, or the more accurate measurement of the impact of the forming process at the scale of the grain. But to enhance structural performance for architectural applications requires that both aspects are considered synthetically. We demonstrate a mesh-based approach that incorporates critical parameters at the scales of structure, element and material. Adaptive mesh refinement is used to support localised variance in resolution and information flow across these scales. The adaptation of mesh resolution is linked to structural analysis, panelisation, local geometric formation, connectivity, and the calculation of forming strains and material thinning.

Computational Strategies for the Architectural Design of Bending Active Structures

Active bending introduces a new level of integration into the design of architectural structures, and opens up new complexities for the architectural design process. In particular, the introduction of material variation reconfigures the design space. Through the precise specification of their stiffness, it is possible to control and pre-calibrate the bending behaviour of a composite element. This material capacity challenges architectures existing methods for design, specification and prediction. In this paper, we demonstrate how architects might connect the designed nature of composites with the design of bending-active structures, through computational strategies. We report three built structures that develop architecturally oriented design methods for bending-active systems using composite materials. These projects demonstrate the application and limits of the introduction of advanced engineering simulation into an architectural workflow, and the extension of architectures existing physics-based approaches.

SCRIM – Sparse Concrete Reinforcement in Meshworks

This paper introduces a novel hybrid construction concept, namely Sparse Concrete Reinforcement In Meshworks (SCRIM), that intersects robot-based 3D Concrete Printing (3DCP) and textile reinforcement meshes to produce lightweight elements. In contrast to existing 3DCP approaches, which often stack material vertically, the SCRIM approach permits full exploitation of 6-axis robotic control by utilising supportive meshes to define 3D surfaces onto which concrete is selectively deposited at various orientation angles. Also, instead of fully encapsulating the textile in a cementitious matrix using formworks or spraying concrete, SCRIM relies on sparsely depositing concrete to achieve structural, tectonic and aesthetic design goals, minimising material use. The motivation behind this novel concept is to fully engage the 3D control capabilities of conventional robotics in concrete use, offering an enriched spatial potential extending beyond extruded geometries prevalent in 3DCP, and diversifying the existing spectrum of digital construction approaches. The SCRIM concept is demonstrated through a small-scale proof-of-concept and a larger-scale experiment, described in this paper. Based on the results, we draw a critical review on the limitations and potentials of the approach.

Multiscale modeling frameworks for architecture: Designing the unseen and invisible with phase change materials

Multiscale design and analysis models promise a robust, multimethod, multidisciplinary approach, but at present have limited application during the architectural design process. To explore the use of multiscale models in architecture, we develop a calibrated modeling and simulation platform for the design and analysis of a prototypical envelope made of phase change materials. The model is mechanistic in nature, incorporates material-scale and precinct scale-attributes, and supports the design of two- and three-dimensional phase change material geometries informed by heat transfer phenomena. Phase change material behavior, in solid and liquid states, dominates the visual and numerical evaluation of the multiscale model. Model calibration is demonstrated using real-time data gathered from the prototype. Model extensibility is demonstrated when it is used by designers to predict the behavior of alternate envelope options. Given the challenges of modeling phase change material behavior in this multiscale model, an additional multiple linear regression model is applied to data collected from the physical prototype in order to demonstrate an alternate method for predicting the melting and solidification of phase change materials.

Machine learning for architectural design: Practices and infrastructure:

In this article, we propose that new architectural design practices might be based on machine learning approaches to better leverage data-rich environments and workflows. Through reference to recent architectural research, we describe how the application of machine learning can occur throughout the design and fabrication process, to develop varied relations between design, performance and learning. The impact of machine learning on architectural practices with performance-based design and fabrication is assessed in two cases by the authors. We then summarise what we perceive as current limits to a more widespread application and conclude by providing an outlook and direction for future research for machine learning in architectural design practice.

An Integrated Modelling and Toolpathing Approach for a Frameless Stressed Skin Structure, Fabricated Using Robotic Incremental Sheet Forming

For structural assemblies that depend upon robotic incremental sheet forming (ISF) the rigidity, connectivity, customization and aesthetics play an important role for an integrated and accurate modeling process. Furthermore, it is critical to consider fabrication and forming parameters jointly with performance implications at material, element and structural scales. This paper briefly presents ISF as a method of fabrication, and introduces the context of structures where the skin plays an integral role. It describes the development of an integrated approach for the modelling and fabrication of Stressed Skins, an incrementally formed sheet metal structure. The paper then focus upon the use of prototypes and empirical testing as means to inform digital models about fabrication and material parameters including: material forming limits and thinning; the parameterisation of macro and meso simulations with calculated and observed micro behaviour; the organisation and extraction of toolpaths; and rig setup logics for fabrication. Finally, the validity of these models is evaluated for structural performance, and for geometric accuracy at multiple scales.