Anna Krtschil

Zusammenfassung

The increasing use of timber in multi-story construction has highlighted challenges related to the vibration behavior of timber floor slabs, affecting both structural and acoustic performance. Floor vibrations between 0 and 20 Hz and structure-borne sound especially between 50 and 100 Hz are impairing the user comfort and serviceability. This paper investigates a mono-material approach using wooden tuned mass dampers (TMDs) to reduce these vibrations in timber slabs, particularly in buildings with long spans. Eigenmodes in relevant frequency ranges are first identified, followed by the separate design and interdisciplinary integration of TMDs for structural and acoustic performance. The study integrates acoustic and structural design requirements through an interdisciplinary process, employing both experimental and numerical models. Results demonstrate that wooden TMDs can address both disciplines and reduce deflection in timber slabs and improve structure-borne and low-frequency sound transmission.

Zusammenfassung

Modular floor slabs must be subdivided into prefabricable, transportable segments. This slab segmentation process conventionally uses a rectangular pattern, particularly for timber buildings. Regular segmentation patterns and strict column grids are ideal for rectangular building shapes, but restrict timber buildings to only some architectural uses, and are unideal for urban infill. Unfortunately, planning and constructing multi-storey wood buildings without a strict grid is still challenging. There is therefore a conflict between the desired column placement and the constraints imposed by building systems. This article investigates novel methods for segmenting timber floors supported by irregular column layouts. It proposes six different segmentation methods that are informed through Co-Design by structural, material waste, and transportation requirements. Co-Design allows for the direct integration and automated feedback of such diverse criteria into the early building design phase. These methods are based on three well-known computational approaches: Single-Objective Optimisation, Parametric Modelling, and Agent-Based Modelling. They could also be applied to other non-timber prefabricated floor systems. The segmentation methods are demonstrated on two example floor slabs with irregular column layouts, one with a rectilinear and the other with an irregular outline. The methods are compared using quantitative proxies for cost, fabrication time, architectural adaptability, and assembly complexity. More benchmark testing is needed, but initial results showed that the most efficient segmentations cannot adapt to irregular layouts, emphasising the need for a more adaptable approach to modular timber construction.

Zusammenfassung

Climate change requires the economical use of all raw materials, including renewable construction materials such as timber. The aim of this study is to understand the interdependencies between structural and nesting performance to define the segmentation method that uses the least raw material. To do this, six segmentation methods are compared for 16 floor plans. Based on these simulations the amount of raw material needed per project is estimated for two timber building systems: one solid and the other hollow. Two of the developed segmentation methods are competitive with the commonly used regular segmentation method in terms of their raw material use. The overall performance however is dependent on the column layout, the boundary shape of the floor plan, and the chosen building system.

Zusammenfassung

To meet climate change goals and respond to increased global urbanisation, the building industry needs to improve both its building technology and its design methods. Constrained urban environments and building stock extensions are challenges for standard timber construction. Co-design promises to better integrate disciplines and processes, promising smaller feedback loops for design iteration and building verification. This article describes the integrated design, fabrication, and construction processes of a timber building prototype as a case study for the application of co-design methods. Emphasis is placed on the development of design and engineering methods, fabrication and construction processes, and materials and building systems. The development of the building prototype builds on previous research in robotic fabrication (including prefabrication, task distribution, and augmented reality integration), agent-based modelling (ABM) for the design and optimisation of structural components, and the systematisation of timber buildings and their components. The results presented in this article include a functional example of co-design from which best practises may be extrapolated as part of an inductive approach to design research. The prototype, with its co-designed process and resultant flat ceilings, integrated services, wide spans, and design adaptability for irregular column locations, has the potential to expand the design potential of multi-storey timber buildings.

Zusammenfassung

This paper proposes an interactive computational approach for designing the layout of timber column-slab structures in a material-saving and structural-performance aware manner. The generated column slab layout meets the serviceability limit state deflection criteria by integrating gradient-based optimization within an agent system approach. This was achieved by extending the ABxM framework with an interactive design framework termed Timber Column Slab (TCS) solver. This solver is underpinned by three data structures: Firstly, an agent system representing a column-slab system for layout exploration. The finite element (FE) model that computes the slab’s nodal displacements, which enables rapid serviceability checks at each agent-system update in a real-time loop. With the TCS extension, the agent-based model uses the numerical analysis results to refine the decision of the adaptive agents. The real-time interaction built within the agent-based model is responsible for the live user guidance and design software integration. The proposed methodology has been built with multiple scientific stacks and encapsulated into an open-source framework in a C# environment. The developed method is tested on a wide range of real building floor plans of different scales and typologies, demonstrating how effective it is compared to previous efforts.

Zusammenfassung

This paper presents a feedback-based computational method for the placement of columns in the early design phase of complex multi-story structures. The method integrates a circle packing algorithm, a spring system, and structural engineering simulations within a single script for the reciprocal and informed arrangement of columns in the space. While allowing the users to have an explorative approach, it empowers diverse potentials in multi-story constructions including additional cantilevering spaces around the boundary, increased spatial qualities with large span possibilities, multidirectional structural arrangements, and multi-purpose use of space. As a result, the developed algorithm allows for flexibility by leveraging the design possibilities of grid-based and irregular column arrangements and promotes the integration of structural and design-related constraints in the spatial organization of various building typologies.

Zusammenfassung

This paper discusses the architectural design potentials of a novel hollow timber slab building system for flexible and adaptive multi-storey timber building typologies. Current timber building systems are defined by their standardized nature, which limits most structures to unidirectional, rigid grids and limits designs to rectilinear layouts. At the same time, recent developments in computational design and digital fabrication open new possibilities to overcome these limitations. In this paper we present four building design applications of a new multi-directional slab building system that allows for a greater level of spatial flexibility and adaptability with free column placement and a tuned network of internal shear webs. These examples expand on previous work through the co-development of building design, skin, building system, and building service integration strategies for a long lifespan and changeable building program. The design applications illustrate open, reprogrammable floor plates that can support three different program states: office, residential, and mixed-use. Furthermore, the novel conceptual approaches to building service integration and the resulting slabs are compared to approaches more common in mass timber construction. Finally, we contextualize the study with related developments and discuss how computational and integrated design thinking could lead to a greater level of design freedom in timber construction and an increased applicability to more complex site conditions than in conventional masstimber construction

Zusammenfassung

The goal of this ongoing research is the development of a novel, digital, modular wood building system, which allows for open-plan, flexible spaces and bespoke architectural solutions. This paper presents a comparison of two new timber building systems for multi-storey construction. The building systems, one solid and one hollow, are developed using an integrative approach that considers structural, fabrication and assembly requirements in the system design process.

Zusammenfassung

Though capable of allowing multi-directional spans, timber products such as cross-laminated timber are primarily utilized uni-directionally using linear supports like walls or beam elements. Recent building designs increasingly show punctual supports but with narrow column grid layouts. Support beams and narrow grids limit the design space for multi-storey timber buildings. To overcome these design limits, an integrative design concept for punctually supported timber slabs is being developed that allows for large spans and irregular column layouts. Therefore, engineering methods are integrated in the architectural design of the building components, such as plates, columns, and their connections. The developed slab system combines hardwood and softwood materials in a sandwich construction. The plates have a tailored internal topology considering the force flow in the slab. A plate-to-plate connection design is evaluated through mechanical tests, which also serve as calibration for the global structural model. The research findings are validated through the design and construction of a large scale demonstrator: the ITECH Campus Lab.

Zusammenfassung

The arrangement of columns and their spacing in multi-story timber construction is restricted to rectangular grids by the production and shipping sizes of floor assemblies. This is particularly true for hollow box floor systems, for which the punctual supports must be placed at the reinforced edges of the hollow boxes. The arrangement of the columns and their spacing is thereby restricted by the production and shipping sizes of the box ceilings to rectangular grids. To overcome these design limits a new wooden box building system is developed that allows for irregular column layouts through a tailored slab interior design. This development allows for the increased applicability of timber floor systems regardless of site shape or architectural design intent. The slab interior design is dependent on occurring forces and fabrication requirements. Three methods for the internal slab layout are developed and compared: a sequential method, a structurally informed agent-based method, and a geometrically informed agent-based method that uses both a sequential and agent-based approach. The structural performance of each method is compared through the analysis of three reinforcement layouts an architectural testing setup.

Zusammenfassung

This paper presents an agent-based method for the design of complex timber structures. This method features a multi-level agent simulation, that relies on a feedback loop between agent systems and structural simulations that update the agent environment. Such an approach can usefully be applied for the design of variable density timber slab systems, where material arrangements based on structural, fabrication, and architectural boundary conditions are necessary. Such arrangements can lead to multi-directional spanning slabs that can accept pointwise supports in unique layouts. We discuss the implementation of such a method on the basis of the structural design of a pavilion-scale multi-storey testing setup. The presented method enables a more versatile approach to the design of multi-storey timber buildings, which should increase their applicability to a diverse range of building typologies.