ABSTRACT
Despite the r elative brittleness of large tim ber members loaded in bending, s hear or tension, structures built from such material are widely considered to perform well during seismic events. The good seismic behaviour is often attributed to the high ratio between strength and mass that complete structures built primarily from timber components possess and the ability of such systems to dampen and at tenuate motions resulting from ground shaki ng. However, t his does not mean that timber structures per se are inherently resistant to seismic actions and like those made primarily from other materials, particular ti mber construction systems owe any ability to resist damaging effec ts o f ex ternal mechanical actions to m any factors. Firstly , it is im portant for good performance that constructed systems employ inherently stable geometric forms at complete system or substructure levels and t hat if localised damage occurs s ystems are capab le of developing alternative load paths. Secondly, and especially under seismic actions, it is important that systems and substructures be able to accommodate local distortions in components without failure of any members or connections in primary load paths. This capability, in turn, depends on the geo metry of co mponents and o n how appropri ately t hey combine materials. These requirements reflect that the ability of many timber structures to absorb kinetic energy and attenuate effects of large amplitude ground motions is strongly dependent on energy dissipation associated with plastic deformation of metal parts in mechanical connections and localised pseudoplastic compressive deformation of timber at carpentry of mechanical connections.
