The paper is dedicated to the numerical analysis of a single-step joint, enabling the prediction of stiffness and failure modes of both single- and double-step joints. An experimental analysis of the geometrically simplest version, the single-step joint, serves as a reference for the calibration of the subsequent finite element model. The inhomogeneous and anisotropic properties of solid timber make detailed modelling computationally intensive and strongly dependent on the respective specimen. Therefore, the authors present a strategy for simplified but still appropriate modelling for the prediction of local failure at certain load levels. The used mathematical approach is based on the linear elasticity theory and orthotropic material properties. The finite element calculations are performed in the environment of the software Abaqus FEA. The calibrated numerical model shows a good conformity until first failures occur. It allows for a satisfactory quantification of the stiffness of the connection and estimation of the force when local failure begins and is, therefore, recommended for future, non-destructive research of timber connections of various shapes.

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Timber truss systems are very efficient load-bearing structures. They allow for great freedom in design and are characterised by high material use in combination with a low environmental impact. Unfortunately, the extensive effort in design and production have made the manufacturing and application of these structures, in this day and age, a rarity. In addition, the currently mainly used steel gusset plates adversely affect the costs and environmental impact of the trusses. The authors’ goals are to optimise the design of timber trusses and to solely use wood for all building components. The two research areas, (1) optimisation of the truss geometry and (2) optimisation of the joints by using solely wood–wood connections, are addressed in this paper. The numerical optimisation strategy is based on a parametric design of the truss and the use of a genetic solver for the optimisation regarding minimal material consumption. Furthermore, first results of the tensile and compression behaviour of the chosen wood–wood connections are presented. The basic idea for the joints is to use a plywood plate as a connector, which is inserted into the truss members and fixed with wooden pegs. The housing of the new robot laboratory located at BOKU Vienna is considered a special case study for the research and serves as an accompanying example for the application of the research within the present paper.

<p>Currently, laminated timber is widely used. The gluing allows for higher part length and involves an advantageous behavior regarding deformations due to shrinkage and lead to better, more regular mechanical properties. The drawback is a low material utilization factor. Starting from a tree trunk, only 25-30 % are part of the final product. Thus, the high-quality product has to be used as efficient as possible.</p><p>At moment mostly, plate girders made of laminated timber are used as a result of the efficient industrialized manufacturing process. If in comparison a truss system is used, a similar load bearing capacity and stiffness can be achieved with much less material effort. The aim of the authors is to industrialize the design and manufacturing process of timber truss systems to be able to compete with the common plate girder systems. The complete process starting from the design, static optimization, work preparation to production process will be cumulated in a continuous digital approach. The paper describes the research approach and experiments about the digital production (by use of a robot arm) and load bearing behavior of different wood- wood connections as first development step. In addition, the design of 1:1 load tests at different timber trusses as well as comparable plate girders is presented.</p>

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