Splitting Strength of Small Dowel-Type Timber Connections: Rivet Joint Loaded Perpendicular to Grain

Abstract

The existing models for the prediction of the splitting failure of dowel-type connections loaded perpendicular to grain are determined generally based on crack growth of the entire member cross-section. These models can be appropriate for stocky or rigid fasteners installed through the full thickness of the wood member. However, for slender dowel-type fasteners such as timber rivets, particularly when the penetration depth of the fastener does not cover the whole member thickness, the crack formation is different. Observations from current tests in thick members show that the crack growth across the grain occurs to a depth corresponding to the effective embedment depth of the fastener and propagates along the grain until it reaches its unstable condition. The design method presented in this paper to predict the connection splitting capacity takes into account the observed two possible failure modes of wood: either partial or full width splitting. In the proposed method, the effect of geometry parameters such as connection width and length, fastener penetration depth, loaded and unloaded edge distances, end distance, and member thickness as observed by others are considered. Results of the tests undertaken with laminated veneer lumber (LVL) and glulam manufactured from New Zealand Radiata Pine (RP) and data available from literature confirm the validity of this new method and show that the proposed design approach can be used advantageously in comparison to other existing models for timber rivet connections under transverse loading.