Hysteretic modelling of moment-resisting nailed timber joints

While nailed timber joints have been used for many years, attention is now being focussed on producing nailed joints that have a significant moment resistance. Such joints can be made using steel sideplates and the increased moment resistance over more traditional nailing could be utilised to resist seismic loads. Like steel and concrete members used to resist seismic loads, the timber members and joints need to be modelled sufficiently accurately in order that computer models of the structures will provide adequate predictions of the overall seismic behaviour. This paper discusses hysteretic models and proposes a model for nailed timber joints (based on the modified Takeda model previously used for concrete models) that incorporates the pinching effect that is observed in tests on moment-resisting nailed timber joints. The behaviour of two simple portal frames under the El Centro 1940 earthquake record is discussed. Values for the model parameters were obtained from tests reported elsewhere.