A Review of Mechanical Behavior and Failure Modes of Multi-Row Large-Diameter Dowel-Type Connections in Timber Structures

Abstract

Multi-row large-diameter dowel-type connections are widely used in timber structures for their high load-carrying capacity and convenient construction, but their brittle failure behavior is not yet fully covered by current design codes. This paper reviews the mechanical behavior and failure modes of such connections by synthesizing experimental, theoretical and numerical studies published mainly between 2000 and 2025 and by comparing the relevant Chinese, European and North American design provisions. The results show that load-carrying capacity, stiffness, slip and ductility are governed by coupled geometric and material parameters; the group effect causes non-uniform load distribution among the dowels; and brittle failures such as splitting, row shear and block shear depend mainly on end distance, edge distance, spacing and the ratio of wood thickness to dowel diameter, for which current code provisions differ noticeably. Experiment-validated numerical simulation is a reliable tool for studying these mechanisms. Accurate quantification of the group effect, prediction and control of brittle failure, and multi-factor coupling should be research priorities, particularly for improving the Chinese design provisions.