Drawing a blank – design modelling composite timber elements

Abstract

The shift towards bio-economies of architectural fabrication necessitates particular consideration of how characterizing aspects of bio-materials such as heterogeneity and anisotropy impact the designed performance of architectural elements. These aspects must be integrated into the modelling and representation of architecture and must be instrumentalised for digital design and fabrication processes. The use of timber in construction is challenging due to its complex material behaviours, and therefore robust methods for predicting and modelling these are crucial for exploiting the timber resource more effectively. In light of this, we focus on developing a holistic and integrated digital modelling approach for glue-laminated timber construction elements that connects the digital design model to the specific material resource and incorporates its material complexity into design simulation workflows. We question the role of the lamella in the glulam blank and trace its agency through a series of four disparate projects, from an initially silent and generic constituent of the blank to a key, operative actor in the design of performance-graded timber products through the added specificity of material composition and a liberation of its form. The first project develops a modelling approach that connects material specification and lamella sizing to free-form timber element geometries. It uses principles of industrial glulam production and knowledge of the anisotropic nature of timber to speculate on new forms of glulam blanks that could arise from a deeper engagement with the glue-lamination process. The second project looks further back in the timber value chain at the processing of the specific forest resource into tailored building elements, attaching a material specificity to the lamella. The third project expands the modelling and prototyping of non-standard glulam blanks into considerations of timber waste streams and aesthetics. The final project aims to further speciate the lamella by tailoring its form as well as its material composition to respond to simulated performance demands. Through these projects we outline the development of a novel digital framework that begins as a modelling approach for free-form glulam beams and grows to accommodate the mapping and allocation of specific, heterogeneous input material. As the digital framework matures, increasingly detailed and interlinked digital simulations of mechanical performance are integrated.