Simplified Calculation Model for Typical Dou-Gong Exposed to Vertical Loads

Early Chinese traditional timber buildings preserved until now are mainly ancient buildings built in the time of the Song and Yuan dynasties (960–1368 AD). Dou-gongs of these ancient timber buildings are complex structures. Their complexities, however, are difficult to fully consider in large-scale structural analyses. Therefore, it is necessary to develop a reliable simplified modeling of Dou-gongs, which is applicable for large-scale analyses. In this study, the features of Dou-gongs of early Chinese traditional timber buildings were firstly reviewed, referring to the historical literature and on-site investigation. Then, the mechanical behavior of typical Dou-gongs exposed to vertical loads was examined through refined finite element analyses, where the solid elements were adopted and geometric characteristics were considered. According to the results of the load transferring path, a new beam-truss model representing a simplified Dou-gong was developed, and its accuracy was numerically verified. The results showed that the gravity load of the roof above the column is transferred down through the central axis; the weight of the overhang of the roof is transferred diagonally to the bottom of the Dou-gong, passing through the front of the cantilever components; in the collapse condition, the vertical load is transferred to the two sides through horizontal beams. Compared with the results of the refined model, the new beam-truss model proposed shows an acceptable computational accuracy concerning stress, deformation and stiffness, with 90–97% reduction in the calculation time consumption, which makes it suitable for large-scale structural analyses of early Chinese traditional timber buildings.