Research on the simplified model for early Chinese Dou-gong under horizontal load

Dou-gong is one of the most crucial joints in traditional Asian timber buildings. However, due to its complex structural construction, it is challenging to develop a simplified model that balances computational efficiency and accuracy in large-scale seismic analysis. Therefore, the motivation of this study is to establish a simplified model for the early style Dou-gong used in East Asia under horizontal load. Firstly, a nonlinear refined finite element (FE) analysis considering elastoplastic damage and contact behavior is performed for the Dou-gong. Secondly, force flow analysis is conducted to extract the load transferring path and determine the beam distribution in the simplified model. Then, based on the embedded pressure theory, a method is developed to determine the cross-sectional dimensions of the simplified model. Finally, low-cycle hysteretic experiments on three typical Dou-gong joints are carried out, and comparisons are made between the refined finite element (FE) models and the simplified models. The results indicate that the computational efficiency of the simplified model is 820–1110 times higher than that of the refined FE models. In terms of accuracy, the hysteretic envelope area error of the simplified model compared to the experimental results ranges from −12.33–0.33 %, the R² of secant stiffness ranges from 0.801 to 0.910, the R² of hysteretic energy ranges from 0.791 to 0.933, and the R² of skeleton curve ranges from 0.949 to 0.961. The findings of this study provide a scientific basis for seismic analysis of timber architectural heritages and offer a simplified model for the seismic performance evaluation of Dou-gong that balances both computational efficiency and accuracy.