The Analytical Model and Horizontal Resistance of the Column-Head Dou-Gong in the Traditional Chinese Timber Structure

ABSTRACT

To study the horizontal resistance of the column-head Dou-Gong (CHDG) in the traditional Chinese timber structure, the analytical model of CHDG without or with horizontal gap was proposed in this study. According to the structural form analysis of CHDG, the analytical model of CHDG considers the contact relationship between the components. CHDG has several distinct layers, of which the first layer is modeled as a rotation spring element and the second layer and above of CHDG are modeled as shear spring elements. Then, the horizontal resistance of CHDG was analyzed, and the horizontal load-displacement relationship of CHDG with horizontal gap appears triple polyline, while CHDG without horizontal gap is bilinear. Finally, the effects of parameters, including the length or width of Dadou bottom, height of Mantousun (MTS), width of horizontal gap, and vertical load, on the horizontal resistance was analyzed. The horizontal resistance of CHDG increases significantly with the length or width of the Dadou bottom, height of MTS, and vertical load increase, while the horizontal resistance of CHDG decreases significantly with width of horizontal gap increases.

HIGHLIGHTS

This study proposes theanalytical model of column-head Dou-Gong considering the interface between Dadou, Mantousun, and column head. Owning to the mechanical performances of semi-rigid joint of column-head Dou-Gong, the spring model is the core part of the analytical model of column-head Dou-Gong. The main conclusions are summarized as follows.

(1) Analytical model of column-head Dou-Gong without or with horizontal gap containing the Dadou model and Mantousun model are established. It is assembled from a model among its different components. There is a rotation that occurs at the first layer of the column-head Dou-Gong and it is modeled as a rotation spring element; the second layer and above of th ecolumn-head Dou-Gong is modeled as shear spring elements, while the connecting beams are modeled by beam elements.

(2) The horizontal resistance increases significantly as the length or width of the Dadou bottom increases. The relationship betweenthe displacement of intersection point 1 and the length or width of the bottom of the Dadou is a positive correlation. Displacement of intersection point 1 is a key parameter that affects the horizontal resistance. Therefore, in the restoration and protection of traditional Chinese timber structures, the goal of increasing the horizontal resistance, can be achieved by increasing the length or width of the Dadou bottom.

(3) Compared with the column-head Dou-Gong without horizontal gaps, the column-head Dou-Gong with horizontal gaps will significantly reduce the horizontal resistance. The existence of horizontal gaps will greatly delay the bearing ofthe load on Mantousun, i.e. the Mantousun will play the bearing role later.

KEYWORDS:

• Analytical model
• column-head dou-gong
• horizontal resistance
• rotation spring
• shear spring

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Ke Liu carried out the derivation, calculation, and writing of the paper. Qingshan Yang made the conception, framework, and guidance of the paper. Pan Yu participated in the derivation and editing.

Additional information

Funding

The work is supported by National Key Research and Development Program of China [2023YFF0906304], National Natural Science Foundation of China [52221002, 52308324 and 52108266], the 111 project of the Ministry of Education and the Bureau of Foreign Experts of China [No. B18062], Chongqing Science and Technology Plan Project Science and Technology Talent Training Program (Academician special) [2022YSZX-JCX0013CSTB] and Fundamental Research Program of Shanxi Province [202303021222004].