Seismic performance investigation of the Dou-gong joints of traditional Chinese timber structures

A Dou-gong joint is one of the essential components in traditional Chinese timber structures. This work investigates the seismic performance of Dou-gong joints under cyclic loading through experiments and model calibration. Four full-scale joints were subjected to cyclic loading to study the failure mechanism and ability to dissipate energy. The test results indicated that a Dou-gong joint will finally fail with a large overall tilt. The Dou-gong joint itself had a strong ability to dissipate energy through shear deformation and the extrusion of different components. The maximum load-bearing capacity in the Y direction was larger than that in the X direction because the Dou and Xiao components perform better in the Y direction than in the X direction. A macro model whose nonlinearity was governed by a spring element was used to model a Dou-gong joint. The spring element was separately assigned to two different hysteretic models, and the model parameters were calibrated using the tested data. Both the advantages and disadvantages of the two hysteretic models are compared and discussed. The obtained seismic performance of a Dou-gong joint provides useful and valuable information to maintain and retrofit historic Chinese timber structures.