The growing timber manufacturing industry faces challenges due to increasing geometric complexity of architectural designs. Complex and structurally efficient curved geometries are nowadays easily designed but still involve intensive manufacturing and excessive machining. We propose an efficient form-giving mechanism for large-scale curved mass timber by using bilayered wood structures capable of self-shaping by moisture content changes. The challenge lies in the requirement of profound material knowledge for analysis and prediction of the deformation in function of setup and boundary conditions. Using time- and moisture-dependent mechanical simulations, we demonstrate the contributions of different wood-specific deformation mechanisms on the self-shaping of large-scale elements. Our results outline how to address problems such as shape prediction, sharp moisture gradients, and natural variability in material parameters in light of an efficient industrial manufacturing.
Recent development in research and practice for curved cross-laminated timber (CLT) opens up novel and interesting possibilities for applications of slender surface-active shell structures in architecture. Such typologies provide advantageous structural behaviour allowing for efficient and lightweight structures while simultaneously determine the envelope and space of a building. The high degree of prefabrication combined with a sustainable and renewable building material makes CLT an ecological and economic solution for future construction. This paper presents the design development and construction of the Urbach Tower for the Remstal Gartenschau 2019: a structure made from high curvature CLT components on a building scale. This research contribution illustrates a sophisticated integrative design to construction process emphasizing computational and structural design, fabrication and detailing for curved timber components in complex spatial structures. The authors further explore the structural potential of self-shaped curved CLT investigating the influence of curvature radius on the load-bearing behaviour of the tower structure. The Urbach Tower translates these technical developments into practice arising at the intersection of digital innovation and scientific research.