Daniel Brandon

Modelling of Non-metallic Timber Connections at Elevated Temperatures

Models estimating the slip modulus and the load capacity, including temperature dependent effects, of non-metallic timber connections are presented. Previous studies, including the work of Thomson, have shown that ‘Glass Fibre Reinforced Polymer’ (GFRP) rods are suitable connectors for timber and that ‘Densified Veneer Wood’ (DVW) functions effectively as a flitch plate material. Thomson’s model predicting the slip modulus of the connection with GFRP rods and DVW plates is revised in this paper. The revised model is used to predict the slip modulus and the failure load at room temperature and elevated temperatures. The latter is achieved by predicting local temperatures in the connection and taking corresponding reduced material properties into account.

Timber under real fire conditions – the influence of oxygen content and gas velocity on the charring behavior

PurposeThe purpose of this study is to investigate the influencing factors on the charring behaviour of timber, the char layer and the charring depth in non-standard fires.Design/methodology/approa ...

Stiffness Modelling of Non-metallic Timber Connections with Pultruded Dowels

Previous studies have shown that double shear timber connections with glass fibre reinforced polymer dowels are a viable alternative to metallic timber connections. Different models have been proposed for predicting the load capacity of the connection. A model which accurately predicts stiffness for connections of this type is, however, not yet published. This paper discusses a two dimensional linear finite element model that predicts the slip modulus of non-metallic timber connections made with pultruded dowels. The model is compared to experimental results and it is concluded that the two dimensional model is accurate.

Structural Performance and Advantages of DVW Reinforced Moment Transmitting Timber Joints with Steel Plate Connectors and Tube Fasteners

This paper presents a study to the moment-rotation aspects of two 3-member DVW reinforced timber connections with an inter-connecting steel plate used as middle member. Previous studies showed that reinforcing dowel-type timber connections with ‘densified veneer wood’ (DVW) and using expanded tube fasteners results in connections with superior structural properties compared to all conventional connections. In this connection type, the DVW prevents premature timber splitting. The tube fasteners aid a high initial stiffness, a high ductility and a high reliability. A drawback of the connection, already in a 3-member connection, is the total thickness. By using only two side members and a much thinner, steel middle member, the thickness is strongly reduced. The steel middle member is used as a connecting interface in a flitch plate connection. This generally results in a 50% reduction of the rotational stiffness. However, it is shown by an analytical and numerical study, that the rotational stiffness of two closely spaced, flitch plate DVW connections acting in series remains unchanged if certain conditions are fulfilled. Two full connection tests are performed to confirm the analytical and numerical results. Additionally, the paper presents a comparison to a conventional connection, which confirms the structural quality of the reinforced connection.