Timber frame connections
Table of contents
Project data
| Titel | Title Nichtmetallische mechanische Verbindungen für Holztragwerke | Non-metallic mechanical joints for timber trusses Förderer | Funding Bundesministerium für Wirtschaft und Energie (BMWi) Zeitraum | Period 07.2014 – 12.2016 Leiter | Project manager Prof. Dr.-Ing. Peer Haller (Institut für Holzbau, TU Dresden) Bearbeiter | Contributors M.Sc. Siavash Namari, Dipl.-Ing. Jörg Wehsener, Dr.-Ing. Jens Hartig (Institut für Holzbau, TU Dresden) Projektpartner | Project Partners STRAB Ingenieurholzbau Hermsdorf GmbH, Hermsdorf | EBF Dresden GmbH, Dresden |
Report in the year book 2016
Non-metallic mechanical joints
n the last time, there has been renewed interest in timber in the construction industry because of its sustainability, adaptability and aesthetic properties. This trend can be seen in the case of warehouses for aggressive substances like salt, fertilizer or chemicals, which are built with timber as a very resistant material against such critical environmental conditions in contrast to steel. However, the load bearing capacity of large timber structures is strongly depending on the design of connections and joints, which are mostly constructed with steel components. Hence, reducing the amount of metal used within a timber structure has many advantages including durability, reducing thermal bridging and less weight of the structures. In Eurocode 5, design guidance for connections is provided, but this code only provides guidance for mechanical connections made of metallic and wooden components. The absence of design guidance for alternative connector materials is a restriction that should be removed.
Therefore, in this study, by means of an experimental program and developing numerical and analytical models, it is tried to provide a sound knowledge for mechanical non-metallic connections. Through a small scale experimental testing program, potential materials – glass fibre reinforced plastics (GFRP), densified veneer wood and laminated veneer lumber – in the form of plates and dowels in different test configurations were surveyed and investigated. Analytical and numerical models were developed for a better understanding of the load-bearing behaviour and to perform static verifications. The models were validated based on the experimental results. In the next step, real scale tests (truss models were about 6 meter long and 1 meter high) in Otto-Mohr-Laboratory of the TUDresden have been performed. The data from tests are captured and analysed.
The results demonstrate that the combination of GFRP dowels with GFRP plates has almost same bearing capacity in comparison to the steel-to-steel connections and also have a more ductile behaviour. Therefore, use of this combination can provide a robust connection system for contemporary applications.